Malic Acid
100 Scientific Studies About Malic Acid
Malic
Acid |
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- Search all fields for: malic acid
- Published in 1980 through 1999
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Documents: 1 to 100 of 656
NLM database Documents
Record 1 from database: MEDLINE
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- Title
- Structure and expression of murine malic enzyme mRNA.
Differentiation-dependent accumulation of two forms of malic enzyme mRNA in
3T3-L1 cells.
- Author
- Bagchi S; Wise LS; Brown ML; Bregman D; Sul HS; Rubin CS
- Address
-
- Source
- J Biol Chem, 1987 Feb, 262:4, 1558-65
- Abstract
- Many murine cells express two mRNAs with markedly different sizes (2.0 and
3.1 kilobases (kb)) that hybridize with cDNA probes for cytosolic malic enzyme
((S)-malate NADP+ oxidoreductase (oxaloacetate-decarboxylating, EC 1.1.1.40). A
series of overlapping cDNA clones corresponding to 3129 nucleotides of malic
enzyme mRNA was isolated and sequenced to determine the relationship between the
two mRNAs and establish the primary structure of mouse malic enzyme. The larger
mRNA has an open reading frame of 1716 nucleotides followed by a 3' untranslated
region of 1348 nucleotides. The sequence of an exceptionally G/C-rich (88%)
portion (65 nucleotides) of the 5' noncoding region was also established. An
uncommon poly A addition signal (AUUAAA) is used during the processing of the
3.1-kb mRNA. The 2.0-kb mRNA results from the utilization of another poly A
addition signal that truncates the 3' noncoding sequence by approximately 1 kb.
The mRNA coding sequence indicates that the malic enzyme subunit contains 572
amino acid residues and has a Mr of 64,000. Two putative components of an
NADP-binding domain are located between residues 100 and 165. During the
differentiation of 3T3-L1 preadipocytes into adipocytes both the rate of
synthesis and relative mRNA concentration for malic enzyme and another lipogenic
enzyme, ATP-citrate lyase, are coordinately increased 5-7-fold. However, as
preadipocytes approach confluence, the mRNA levels for both lipogenic enzymes
transiently increase 3-4-fold, whereas the rates of synthesis of the two
proteins are only slightly elevated. Thus, lipogenic enzyme expression is
controlled at a pretranslational level during adipogenesis, but the accumulation
of the same enzymes may also be subject to translational control in the
fibroblast-like preadipocytes. In contrast, mRNA coding for a third enzyme
required for lipogenesis, glycerol-3-phosphate dehydrogenase, is not detected in
3T3-L1 preadipocytes, but rapidly accumulates during adipocyte development.
- Language of Publication
- English
- Unique Identifier
- 87109297
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- MeSH Heading (Major)
- Malate Dehydrogenase|BI/*GE; Nucleic Acid Conformation|*
- MeSH Heading
- Adipose Tissue|CY/EN; Amino Acid Sequence; Animal; Base Sequence; Cell
Differentiation; Cell Line; Gene Expression Regulation; Glycerolphosphate
Dehydrogenase|BI/GE; Mice; Multienzyme Complexes|BI/GE; Oxo-Acid-Lyases|BI/GE;
Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 2 from database: MEDLINE
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- Title
- The cytosolic pathway of L-malic acid synthesis in Saccharomyces cerevisiae:
the role of fumarase.
- Author
- Pines O; Even Ram S; Elnathan N; Battat E; Aharonov O; Gibson D; Goldberg I
- Address
- Department of Molecular Biology, Hebrew University-Hadassah Medical School,
Jerusalem, Israel. ophry@md2.huji.ac.il
- Source
- Appl Microbiol Biotechnol, 1996 Nov, 46:4, 393-9
- Abstract
- Saccharomyces cerevisiae accumulates L-malic acid but not only minute
amounts of fumaric acid. A 13C-nuclear magnetic resonance study following the
label from glucose to L-malic acid indicates that the L-malic acid is
synthesized from pyruvic acid via oxaloacetic acid. From this, and from
previously published studies, we conclude that a cytosolic reductive pathway
leading from pyruvic acid via oxaloacetic acid to L-malic acid is responsible
for the L-malic acid production in yeast. The non-production of fumaric acid can
be explained by the conclusion that, in the cell, cytosolic fumarase catalyzes
the conversion of fumaric acid to L-malic but not the reverse. This conclusion
is based on the following findings. (a) The cytosolic enzyme exhibits a 17-fold
higher affinity towards fumaric acid than towards L-malic acid; the Km for
L-malic acid is very high indicating that L-malic acid is not an in vivo
substrate of the enzyme. (b) Overexpression of cytosolic fumarase does not cause
accumulation of fumaric acid (but rather more L-malic acid). (c) According to
13C NMR studies there is no interconversion of cytosolic L-malic and fumaric
acids.
- Language of Publication
- English
- Unique Identifier
- 97141384
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- MeSH Heading (Major)
- Cytosol|EN/*ME; Fumarate Hydratase|GE/*ME; Malates|*ME; Saccharomyces
cerevisiae|EN/*ME
- MeSH Heading
- Carbonyl Cyanide m-Chlorophenyl Hydrazone|PD; Citric Acid Cycle|PH;
Ionophores|PD; Kinetics; Mitochondria|EN; Oxaloacetates|ME; Pyruvic Acid|ME;
Substrate Specificity; Support, Non-U.S. Gov't; Support, U.S. Gov't, Non-P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0175-7598
- Country of Publication
- GERMANY
Record 3 from database: MEDLINE
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- Title
- Determination of D-malic acid in apple juice by liquid chromatography:
collaborative study.
- Author
- Eisele TA
- Address
- Tree Top, Inc., Technical Center, Selah, WA 98942, USA.
- Source
- J AOAC Int, 1996 Jan, 79:1, 50-4
- Abstract
- Eleven laboratories collaboratively studied a liquid chromatographic (LC)
method for determination of D-malic acid in apple juice. The mobile phase
consisted of mM L-valine and 8 mM copper acetate adjusted to pH 5.5 with NaOH.
The UV detector was set at 330 nm, and a single reversed-phase LC column was
used. Seven paired samples containing various amounts of D-malic acid ranging
from 0 to 188 mg/100 mL of 12 Brix pasteurized apple juice were tested by each
collaborator. Repeatability and reproducibility coefficients of variation ranged
from 1.0 to 3.5% and 7.7 to 11.7%, respectively, within the range of 26 to 188
mg D-malic acid/100 mL of 12 Brix apple juice. The collaborative study results
demonstrated that the method could quantitate the economic adulteration of apple
juice with DL-malic acid at lower levels than those reported with previous
methods. The LC method for determination of D-malic acid in apple juice has been
adopted first action by AOAC INTERNATIONAL.
- Language of Publication
- English
- Unique Identifier
- 96230021
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- MeSH Heading (Major)
- Beverages|*AN; Chromatography, High Pressure Liquid|*MT; Food Additives|*AN;
Fruit|*; Malates|*AN
- MeSH Heading
- Sensitivity and Specificity; Stereoisomerism
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 1060-3271
- Country of Publication
- UNITED STATES
Record 4 from database: MEDLINE
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- Title
- Transport of malic acid and other dicarboxylic acids in the yeast Hansenula
anomala.
- Author
- Côrte Real M; Leão C
- Address
- Laboratory of Biology, University of Minho, Braga Codex, Portugal.
- Source
- Appl Environ Microbiol, 1990 Apr, 56:4, 1109-13
- Abstract
- DL-Malic acid-grown cells of the yeast Hansenula anomala formed a saturable
transport system that mediated accumulative transport of L-malic acid with the
following kinetic parameters at pH 5.0: Vmax, 0.20 nmol.s-1.mg (dry weight)-1;
Km, 0.076 mM L-malate. Uptake of malic acid was accompanied by proton
disappearance from the external medium with rates that followed Michaelis-Menten
kinetics as a function of malic acid concentration. Fumaric acid,
alpha-ketoglutaric acid, oxaloacetic acid, D-malic acid, and L-malic acid were
competitive inhibitors of succinic acid transport, and all induced proton
movements that followed Michaelis-Menten kinetics, suggesting that all of these
dicarboxylates used the same transport system. Maleic acid, malonic acid, oxalic
acid, and L-(+)-tartaric acid, as well as other Krebs cycle acids such as citric
and isocitric acids, were not accepted by the malate transport system. Km
measurements as a function of pH suggested that the anionic forms of the acids
were transported by an accumulative dicarboxylate proton symporter. The
accumulation ratio at pH 5.0 was about 40. The malate system was inducible and
was subject to glucose repression. Undissociated succinic acid entered the cells
slowly by simple diffusion. The permeability of the cells by undissociated acid
increased with pH, with the diffusion constant increasing 100-fold between pH
3.0 and 6.0.
- Language of Publication
- English
- Unique Identifier
- 90253148
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- MeSH Heading (Major)
- Dicarboxylic Acids|*ME; Malates|*ME; Pichia|*ME; Saccharomycetales|*ME
- MeSH Heading
- Biological Transport, Active; Diffusion; Hydrogen-Ion Concentration;
Kinetics; Succinates|ME; Support, Non-U.S. Gov't; Support, U.S. Gov't,
Non-P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0099-2240
- Country of Publication
- UNITED STATES
Record 5 from database: MEDLINE
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- Title
- Transport of malic acid in the yeast Schizosaccharomyces pombe: evidence for
a proton-dicarboxylate symport.
- Author
- Sousa MJ; Mota M; Leão C
- Address
- Center of Chemical Engineering, University of Porto, Portugal.
- Source
- Yeast, 1992 Dec, 8:12, 1025-31
- Abstract
- The transport system for malic acid present in Schizosaccharomyces pombe
cells, growing in batch culture on several carbon sources, has been studied. It
was found that the dicarboxylic acid carrier of S. pombe is a
proton-dicarboxylate symporter that allows uphill transport and accumulation as
a function of delta pH with the following kinetic parameters at pH 5.0: Vmax =
0.1 nmol of total malic acid s-1 mg (dry weight) of cells-1 and Km = 1.0 mM
total malic acid. Malic acid uptake (pH 5.0) was accompanied by disappearance of
extracellular protons, the uptake rates of which followed Michaelis-Menten
kinetics as a function of the acid concentration. The Km values calculated as
the concentrations either of anions or of undissociated acid, at various
extracellular pH values, pointed to the monoanionic form as the transported
species. Furthermore, accumulated free acid suffered rapid efflux after the
addition of the protonophore carbonyl cyanid m-chlorophenyl hydrazone. These
results suggested that the transport system was a dicarboxylate-proton
symporter. Growth of cells in a medium with glucose (up to 14%, w/v) and malic
acid (1.5%, w/v) also resulted in proton-dicarboxylate activity, suggesting that
the system, besides being constitutive, was still active at high glucose
concentrations. The following dicarboxylic acids acted as competitive inhibitors
of malic acid transport at pH 5.0: D-malic acid, succinic acid, fumaric acid,
oxaloacetic acid, alpha-ketoglutaric acid, maleic acid and malonic acid. In
addition, all of these dicarboxylic acids induced proton movements that followed
Michaelis-Menten kinetics.(ABSTRACT TRUNCATED AT 250 WORDS)
- Language of Publication
- English
- Unique Identifier
- 93190631
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- MeSH Heading (Major)
- Carrier Proteins|*ME; Malates|*ME; Schizosaccharomyces|*ME
- MeSH Heading
- Glucose|ME; Ion Transport; Kinetics; Proton Pump; Succinates|ME; Support,
Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0749-503X
- Country of Publication
- ENGLAND
Record 6 from database: MEDLINE
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- Title
- Regulation of mitochondrial and cytosolic malic enzymes from cultured rat
brain astrocytes.
- Author
- McKenna MC; Tildon JT; Stevenson JH; Huang X; Kingwell KG
- Address
- Department of Pediatrics, University of Maryland School of Medicine,
Baltimor USA.
- Source
- Neurochem Res, 1995 Dec, 20:12, 1491-501
- Abstract
- Malate has a number of key roles in the brain, including its function as a
tricarboxylic acid (TCA) cycle intermediate, and as a participant in the
malate-aspartate shuttle. In addition, malate is converted to pyruvate and CO2
via malic enzyme and may participate in metabolic trafficking between astrocytes
and neurons. We have previously demonstrated that malate is metabolized in at
least two compartments of TCA cycle activity in astrocytes. Since malic enzyme
contributes to the overall regulation of malate metabolism, we determined the
activity and kinetics of the mitochondrial and cytosolic forms of this enzyme
from cultured astrocytes. Malic enzyme activity measured at 37 degrees C in the
presence of 0.5 mM malate was 4.15 +/- 0.47 and 11.61 +/- 0.98 nmol/min/mg
protein, in mitochondria and cytosol, respectively (mean +/- SEM, n = 18-19).
Malic enzyme activity was also measured in the presence of several endogenous
compounds, which have been shown to alter intracellular malate metabolism in
astrocytes, to determine if these compounds affected malic enzyme activity.
Lactate inhibited cytosolic malic enzyme by a noncompetitive mechanism, but had
no effect on the mitochondrial enzyme. alpha-Ketoglutarate inhibited both
cytosolic and mitochondrial malic enzymes by a partial noncompetitive mechanism.
Citrate inhibited cytosolic malic enzyme competitively and inhibited
mitochondrial malic enzyme noncompetitively at low concentrations of malate, but
competitively at high concentrations of malate. Both glutamate and aspartate
decreased the activity of mitochondrial malic enzyme, but also increased the
affinity of the enzyme for malate. The results demonstrate that mitochondrial
and cytosolic malic enzymes have different kinetic parameters and are regulated
differently by endogenous compounds previously shown to alter malate metabolism
in astrocytes. We propose that malic enzyme in brain has an important role in
the complete oxidation of anaplerotic compounds for energy.
- Language of Publication
- English
- Unique Identifier
- 96381600
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- MeSH Heading (Major)
- Astrocytes|DE/*EN/UL; Cytosol|*EN; Homeostasis|*; Malate Dehydrogenase|*ME;
Mitochondria|*EN
- MeSH Heading
- Animal; Aspartic Acid|PD; Cells, Cultured; Citrates|PD; Glutamic Acid|PD;
Ketoglutaric Acids|PD; Lactates|PD; Malates|ME; Rats; Support, U.S. Gov't,
P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0364-3190
- Country of Publication
- UNITED STATES
Record 7 from database: MEDLINE
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- Title
- Experimental sports drinks with minimal dental erosion effect.
- Author
- Meurman JH; Härkönen M; Näveri H; Koskinen J; Torkko H; Rytömaa I; Järvinen
V; Turunen R
- Address
- Department of Cariology, University of Helsinki, Finland.
- Source
- Scand J Dent Res, 1990 Apr, 98:2, 120-8
- Abstract
- The effects of new experimental sports drinks on dental enamel were studied
in vitro using bovine tooth specimens. Profilometric analysis was used to
measure the loss of tooth material after immersion of the specimens in the
drinks. Thereafter the specimens' surface hardness was measured and scanning
electron microphotographs were taken. In addition, 13 commercial sports drinks
and experimental drinks containing either citric acid or malic acid were tested
for their capacity to dissolve hydroxyapatite in vitro. The erosive effect
increased markedly with decreasing pH. The citric acid containing drinks were
more erosive than malic acid containing drinks. No erosion was observed with the
malic acid containing drink (pH 5.90) but the drink of similar composition
containing citric acid caused an erosion 1.3 +/- 1.1 microns deep and a
commercial citric acid containing drink caused a lesion 12.3 +/- 4.5 microns
deep after 120 min immersion. Softening of enamel was greater in specimens
immersed in citric acid than in those immersed in malic acid containing drink.
The in vitro hydroxyapatite dissolving effect of the commercial sports drink
samples studied (all having a pH under 4.22) was markedly greater (0.48-4.38
mmol/l) than that of the malic acid containing experimental drink (pH 5.50, Ca++
concentration in the supernatant 0.19 mmol/l) and of the similar citric acid
containing drink (0.35 mmol/l). The hydroxyapatite dissolving effect of both
drinks started to be marked at a pH level of about 5.0 but increased thereafter
exponentially with decreasing pH. At pH levels above 4.0 the hydroxyapatite
dissolving effect of citric acid containing drinks was greater than that of
malic acid containing drinks.
- Language of Publication
- English
- Unique Identifier
- 90260579
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- MeSH Heading (Major)
- Beverages|*/AE/AN; Tooth Erosion|*ET/PA
- MeSH Heading
- Animal; Calcium|AN; Cattle; Chemistry, Physical; Citrates|AN; Hardness;
Hydrogen-Ion Concentration; Hydroxyapatites|AN; Malates|AN; Microscopy,
Electron, Scanning; Spectrophotometry, Atomic Absorption; Sports; Support,
Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0029-845X
- Country of Publication
- DENMARK
Record 8 from database: MEDLINE
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- Title
- Selective oxidative modification and affinity cleavage of pigeon liver malic
enzyme by the Cu(2+)-ascorbate system.
- Author
- Chou WY; Tsai WP; Lin CC; Chang GG
- Address
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan,
Republic of China.
- Source
- J Biol Chem, 1995 Oct, 270:43, 25935-41
- Abstract
- Pigeon liver malic enzyme was rapidly inactivated by micromolar
concentration of Fe2+ in the presence of ascorbate at neutral pH. The
inactivated enzyme was subsequently cleaved by the Fe(2+)-ascorbate system at
the chemical bond between Asp258 and Ile259 (Wei, C.H., Chou, W.Y., Huang, S.M.,
Lin, C.C., and Chang, G.G. (1994) Biochemistry, 33, 7931-7936), which was
confirmed by site-specific mutagenesis (Wei, C.H., Chou, W.Y., and Chang, G.G.
(1995) Biochemistry 34, 7949-7954). In the present study, at neutral pH, Cu2+
was found to be more reactive in the oxidative modification of malic enzyme and
the enzyme was cleaved in a similar manner as Fe2+ did. At acidic pH, however,
Fe2+ was found to be ineffective in oxidative modification of the enzyme.
Nevertheless, Cu2+ still caused enzyme inactivation and cleaved the enzyme at
Asp141-Gly142, Asp194-Pro195, or Asp464-Asp465. Mn2+ and L-malate
synergistically protect the enzyme from Cu2+ inactivation at acidic pH. Cu2+ is
also a competitive inhibitor versus Mn2+ in the malic enzyme-catalyzed reaction
with Ki value 70.3 +/- 5.8 microM. The above results indicated that, in addition
to the previously determined Asp258 at neutral pH, Asp141, Asp194, and Asp464
are also the coordination sites for the metal binding of malic enzyme. We
suggest that the mechanism of affinity modification and cleavage of malic enzyme
by the Cu(2+)-ascorbate system proceed in the following sequence. First, Cu2+
binds with the enzyme at the Mn2+ binding site and reduces to Cu+ by ascorbate.
Next, the local oxygen molecules are reduced by Cu+, thereby generating
superoxide or other reactive free radicals. These radicals interact with the
susceptible essential amino acid residues at the metal-binding site, ultimately
causing enzyme inactivation. Finally, the modified enzyme is cleaved into
several peptide fragments, allowing the identification of metal site of the
enzyme. The pH-dependent different specificities of metal-catalyzed oxidation
system may be generally applicable for other enzymes or proteins.
- Language of Publication
- English
- Unique Identifier
- 96029696
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- MeSH Heading (Major)
- Ascorbic Acid|CH/*ME; Copper|CH/*ME; Enzyme Inhibitors|CH/*ME; Liver|*EN;
Malate Dehydrogenase|AI/CH/DE/*ME
- MeSH Heading
- Amino Acid Sequence; Animal; Binding Sites; Cations, Divalent|ME;
Malates|ME; Manganese|ME; Models, Chemical; Molecular Sequence Data; NADP|ME;
Oxidation-Reduction; Pigeons; Sequence Homology, Amino Acid; Support, Non-U.S.
Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 9 from database: MEDLINE
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- Title
- Influence of pH, malic acid and glucose concentrations on malic acid
consumption by Saccharomyces cerevisiae.
- Author
- Delcourt F; Taillandier P; Vidal F; Strehaiano P
- Address
- ENSIGC, Laboratoire GÆenie Chimique, URA CNRS 192, Toulouse, France.
- Source
- Appl Microbiol Biotechnol, 1995 May, 43:2, 321-4
- Abstract
- Malic acid consumption by Saccharomyces cerevisiae was studied in a
synthetic medium. The extent of malic acid degradation is affected by its
initial concentration, the extent and the rate of deacidification increased with
initial malate concentration up to 10 milligrams. For malic acid consumption, an
optimal pH range of 3-3.5 was found, confirming that non-dissociated organic
acids enter S. cerevisiae cells by simple diffusion. A full factorial design has
been employed to describe a statistical model of the effect of sugar and malic
acid on the quantity of malate degraded (milligrams) by a given amount of
biomass (milligrams). The results indicated that the initial malic acid
concentration is very important for the ratio of malate consumption to quantity
of biomass. The yeast was found to be most efficient at higher levels of malate.
- Language of Publication
- English
- Unique Identifier
- 95336707
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- MeSH Heading (Major)
- Glucose|*ME; Malates|*ME; Saccharomyces cerevisiae|*ME
- MeSH Heading
- Biomass; Fermentation; Hydrogen-Ion Concentration; Research Design; Support,
Non-U.S. Gov't; Wine|MI
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0175-7598
- Country of Publication
- GERMANY
Record 10 from database: MEDLINE
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- Title
- Malic enzyme and fatty acid synthase in the uropygial gland and liver of
embryonic and neonatal ducklings. Tissue-specific regulation of gene expression.
- Author
- Goodridge AG; Jenik RA; McDevitt MA; Morris SM Jr; Winberry LK
- Address
-
- Source
- Arch Biochem Biophys, 1984 Apr, 230:1, 82-92
- Abstract
- Malic enzyme [L-malate-NADP oxidoreductase (decarboxylating), EC 1.1.1.40]
and fatty acid synthase activities were barely detectable in the uropygial gland
of duck embryos until 4 or 5 days before hatching, when they began to increase.
These activities increased about 30- and 140-fold, respectively, by the day of
hatching. Malic enzyme and fatty acid synthase activities were also very low in
embryonic liver. However, hepatic malic enzyme activity did not increase until
the newly hatched ducklings were fed. Hepatic fatty acid synthase began to
increase the day before hatching and the rate of increase in enzyme activity
accelerated markedly when the newly hatched ducklings were fed. Starvation of
newly hatched or 12-day-old ducklings had no effect on the activities of malic
enzyme and fatty acid synthase in the uropygial gland but markedly inhibited
these activities in liver. Changes in the concentrations of both enzymes and in
the relative synthesis rates of fatty acid synthase correlated with enzyme
activities in both uropygial gland and liver. Developmental patterns for
sequence abundance of malic enzyme and fatty acid synthase mRNAs in uropygial
gland and liver were similar to those for their respective enzyme activities.
Starvation of 4-day-old ducklings had no significant effect on the abundance of
these mRNAs in uropygial gland but caused a pronounced decrease in their
abundance in liver. It is concluded that developmental and nutritional
regulation of these enzymes is tissue specific and occurs primarily at a
pretranslational level in both uropygial gland and liver.
- Language of Publication
- English
- Unique Identifier
- 84177455
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- MeSH Heading (Major)
- Ducks|EM/*ME; Fatty Acid Synthetase Complex|*GE; Gene Expression
Regulation|*; Liver|EM/*EN; Malate Dehydrogenase|*GE; Sebaceous Glands|EM/*EN
- MeSH Heading
- Animal; Animals, Newborn; Chemistry; Electrophoresis, Polyacrylamide Gel;
Food Deprivation|PH; Organ Specificity; RNA, Messenger|ME; Support, Non-U.S.
Gov't; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0003-9861
- Country of Publication
- UNITED STATES
Record 11 from database: MEDLINE
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- Title
- Regulation of genes for enzymes involved in fatty acid synthesis.
- Author
- Goodridge AG; Back DW; Wilson SB; Goldman MJ
- Address
-
- Source
- Ann N Y Acad Sci, 1986, 478:, 46-62
- Abstract
- The levels of malic enzyme and fatty acid synthase are increased by feeding
and decreased by starvation in liver in vivo and are increased by
triiodothyronine and decreased by glucagon in hepatocytes in culture. Cloned
malic enzyme and fatty acid synthase cDNAs are being used to analyze regulation
of these unique genes. Dietary regulation of both enzymes occurs at
pretranslational steps. Increased transcription and increased mRNA stability
contribute about equally to a 20-fold increase in malic enzyme mRNA level when
starved ducklings are refed. In contrast, a 10-fold increase in the level of
fatty acid synthase mRNA is largely accounted for by increased transcription of
this gene. In chick-embryo hepatocytes incubated in serum-free medium containing
insulin, triiodothyronine causes a greater than 10-fold increase in levels of
both malic enzyme and fatty acid synthase mRNAs. Kinetic and inhibitor
experiments suggest a protein intermediate in the increases of malic enzyme and
fatty acid synthase mRNAs caused by triiodothyronine. For malic enzyme, the
stimulation by triiodothyronine is predominantly posttranscriptional. Glucagon
decreases the level of malic enzyme mRNA by 90 to 95%, with regulation occurring
at a posttranscriptional step. Inhibitor experiments suggest that stimulation of
the degradation of malic enzyme mRNA is partially responsible. Glucagon
inhibited fatty acid synthase mRNA level by less than 50%; the inhibited step
has not been identified. Thus, the coordinated regulation of malic enzyme and
fatty acid synthase proteins by nutritional state may involve different hormones
regulating at different points. A surprisingly large component of the regulation
is posttranscriptional.
- Language of Publication
- English
- Unique Identifier
- 87098420
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- MeSH Heading (Major)
- Fatty Acid Synthetase Complex|*GE; Gene Expression Regulation|*; Malate
Dehydrogenase|*GE
- MeSH Heading
- Animal; Cells, Cultured; DNA|IP; DNA, Recombinant; Food; Glucagon|PH;
Liver|EN; RNA, Messenger|ME; Starvation|EN; Support, Non-U.S. Gov't; Support,
U.S. Gov't, P.H.S.; Triiodothyronine|PH
- Publication Type
- JOURNAL ARTICLE; REVIEW
- ISSN
- 0077-8923
- Country of Publication
- UNITED STATES
Record 12 from database: MEDLINE
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- Title
- Detection of adulteration in apple juice by L-malic/total malic acid ratio:
collaborative study.
- Author
- Elkins ER; Heuser JR
- Address
- National Food Processors Association, Washington, DC 20005.
- Source
- J AOAC Int, 1994 Mar, 77:2, 411-5
- Abstract
- L-Malic acid is the predominate acid in pure apple juice and no D-malic acid
should be present. Synthetic malic acid contains 50% D-malic acid, is
inexpensive, and can be used to create nonauthentic apple juice. L-Malic/total
malic ratios of 0.9 or less are indicative of a nonauthentic sample. Fourteen
laboratories participated in a collaborative study to determine the
L-malic/total malic acid ratio in apple juice. Ten samples of apple juice were
sent to each laboratory. Authenticity of the samples varied from 0 to 100%. The
coefficients of variation in all cases were acceptable, i.e., ca 5%. The method
was adopted first action by AOAC INTERNATIONAL.
- Language of Publication
- English
- Unique Identifier
- 94257987
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- MeSH Heading (Major)
- Beverages|*AN; Food Contamination|*; Fruit|*CH; Malates|*AN/CH
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 1060-3271
- Country of Publication
- UNITED STATES
Record 13 from database: MEDLINE
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- Title
- Overexpression of cytosolic malate dehydrogenase (MDH2) causes
overproduction of specific organic acids in Saccharomyces cerevisiae.
- Author
- Pines O; Shemesh S; Battat E; Goldberg I
- Address
- Department of Molecular Biology, Hebrew University-Hadassah Medical School,
Jerusalem, Israel. ophry@md2.huji.ac.il
- Source
- Appl Microbiol Biotechnol, 1997 Aug, 48:2, 248-55
- Abstract
- Saccharomyces cerevisiae accumulates L-malic acid through a cytosolic
pathway starting from pyruvic acid and involving the enzymes pyruvate
carboxylase and malate dehydrogenase. In the present study, the role of malate
dehydrogenase in the cytosolic pathway was studied. Overexpression of cytosolic
malate dehydrogenase (MDH2) under either the strong inducible GAL10 or the
constitutive PGK promoter causes a 6- to 16-fold increase in cytosolic MDH
activity in growth and production media and up to 3.7-fold increase in L-malic
acid accumulation in the production medium. The high apparent Km of MDH2 for
L-malic acid (11.8 mM) indicates a low affinity of the enzyme for this acid,
which is consistent with the cytosolic function in the enzyme and differs from
the previously published Km of the mitochondrial enzyme (MDH1, 0.28 mM). Under
conditions of MDH2 overexpression, pyruvate carboxylase appears to be a limiting
factor, thus providing a system for further metabolic engineering of L-malic
acid production. The overexpression of MDH2 activity also causes an evaluation
in the accumulation of fumaric acid and citric acid. Accumulation of fumaric
acid is presumably caused by high intracellular L-malic acid concentrations and
the activity of the cytosolic fumarase. The accumulation of citric acid may
suggest the intriguing possibility that cytosolic L-malic acid is a direct
precursor of citric acid in yeast.
- Language of Publication
- English
- Unique Identifier
- 97444594
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- MeSH Heading (Major)
- Malate Dehydrogenase|GE/*PH; Malates|*ME; Saccharomyces cerevisiae|*ME
- MeSH Heading
- Citric Acid|ME; Cytosol|EN; Fumarates|ME; Kinetics; Support, Non-U.S. Gov't;
Support, U.S. Gov't, Non-P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0175-7598
- Country of Publication
- GERMANY
Record 14 from database: MEDLINE
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- Title
- Iron-ascorbate cleavable malic enzyme from hydrogenosomes of Trichomonas
vaginalis: purification and characterization.
- Author
- Drmota T; Proost P; Van Ranst M; Weyda F; Kulda J; Tachezy J
- Address
- Department of Parasitology, Faculty of Science, Charles University, Prague,
Czech Republic.
- Source
- Mol Biochem Parasitol, 1996 Dec, 83:2, 221-34
- Abstract
- Two isoforms of NAD(P)(+)-dependent malic enzyme (EC 1.1.1.39) were isolated
from hydrogenosomes of Trichomonas vaginalis. A positively charged isoform at pH
7 was obtained in a single purification step using cation-exchange
chromatography. The second isoform, negatively charged at pH 7.5, was partially
purified using a combination of anion-exchange and affinity chromatography. Both
isoforms displayed similar physical and kinetic properties. Molecular weight
determination of the native enzyme suggested a homotetrameric arrangement of the
60 kDa subunits. The enzyme utilized NAD+ (Km, 6-6.3 microM) preferentially to
NADP+ (Km, 125-145 microM). The NAD(+)-dependent activity showed a broad pH
optimum with maximum under alkaline conditions (pH 9) likely to be present
inside hydrogenosomes. Immunocytochemical studies using a polyclonal rabbit
antibody raised against purified T. vaginalis malic enzyme proved hydrogenosomal
localization of the enzyme. Subfractionation of hydrogenosomes suggested an
association of the malic enzyme with the hydrogenosomal membranes. The 60 kDa
malic enzyme subunit was highly sensitive to non-enzymatic cleavage by an
iron-ascorbate system resulting in two enzymatically inactive fragments of about
31 kDa. Microsequencing of the fragments revealed that the 60 kDa subunit was
cleaved at the metal-binding site between Asp279-Ile280. The enzyme inactivation
was inhibited by an excess of manganese. Iron-dependent posttranslational
modification might contribute to the regulation of malic enzyme activity in
vivo.
- Language of Publication
- English
- Unique Identifier
- 97179499
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- MeSH Heading (Major)
- Malate Dehydrogenase|AN/CH/*IP/*ME; Trichomonas vaginalis|*EN
- MeSH Heading
- Amino Acid Sequence; Animal; Ascorbic Acid|PD; Cell Fractionation;
Chlorides|PD; Ferrous Compounds|PD; Hydrogen-Ion Concentration; Intracellular
Membranes|EN; Isoenzymes|CH/IP/ME; Kinetics; Manganese Compounds|PD; Molecular
Sequence Data; Molecular Weight; NAD|ME; Organelles|EN; Sequence Analysis;
Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0166-6851
- Country of Publication
- NETHERLANDS
Record 15 from database: MEDLINE
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- Title
- Purification and characterization of a malic enzyme from the ruminal
bacterium Streptococcus bovis ATCC 15352 and cloning and sequencing of its gene.
- Author
- Kawai S; Suzuki H; Yamamoto K; Inui M; Yukawa H; Kumagai H
- Address
- Department of Food Science and Technology, Faculty of Agriculture, Kyoto
University, Japan.
- Source
- Appl Environ Microbiol, 1996 Aug, 62:8, 2692-700
- Abstract
- Malic enzyme (EC 1.1.1.39), which catalyzes L-malate oxidative
decarboxylation and pyruvate reductive carboxylation, was purified to
homogeneity from Streptococcus bovis ATCC 15352, and properties of this enzyme
were determined. The 2.9-kb fragment containing the malic enzyme gene was
cloned, and the sequence was determined and analyzed. The enzymatic properties
of the S. bovis malic enzyme were almost identical to those of other malic
enzymes previously reported. However, we found that the S. bovis malic enzyme
catalyzed unknown enzymatic reactions, including reduction of 2-oxoisovalerate,
reduction of 2-oxoisocaproate, oxidation of D-2-hydroxyisovalerate, and
oxidation of D-2-hydroxyisocaproate. The requirement for cations and the optimum
pH of these unique activities were different from the requirement for cations
and the optimum pH of the L-malate oxidative decarboxylating activity. A
sequence analysis of the cloned fragment revealed the presence of two open
reading frames that were 1,299 and 1,170 nucleotides long. The 389-amino-acid
polypeptide deduced from the 1,170-nucleotide open reading frame was identified
as the malic enzyme; this enzyme exhibited high levels of similarity to malic
enzymes of Bacillus stearothermophilus and Haemophilus influenzae and was also
similar to other malic enzymes and the malolactic enzyme of Lactococcus lactis.
- Language of Publication
- English
- Unique Identifier
- 96316385
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- MeSH Heading (Major)
- Malate Dehydrogenase|CH/GE/*IP; Streptococcus bovis|*EN
- MeSH Heading
- Amino Acid Sequence; Base Sequence; Cloning, Molecular; Enzyme Stability;
Hydrogen-Ion Concentration; Keto Acids|ME; Molecular Sequence Data; Molecular
Weight; Pyruvates|ME; Sequence Homology, Amino Acid
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0099-2240
- Country of Publication
- UNITED STATES
Record 16 from database: MEDLINE
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- Title
- Developmental and nutritional regulation of the messenger RNAs for fatty
acid synthase, malic enzyme and albumin in the livers of embryonic and
newly-hatched chicks.
- Author
- Morris SM Jr; Winberry LK; Fisch JE; Back DW; Goodridge AG
- Address
-
- Source
- Mol Cell Biochem, 1984 Sep, 64:1, 63-8
- Abstract
- The mRNAs for fatty acid synthase and malic enzyme were almost undetectable
in total RNA extracted from the livers of 16-day old chick embryos. Both mRNAs
increased in abundance between the 16th day of incubation and the day of
hatching. In neonates, fatty acid synthase mRNA level was dependent on
nutritional status, increasing slowly if the chicks were starved and rapidly if
they were fed. The abundance of malic enzyme mRNA decreased in starved neonatal
chicks and increased in fed ones. When neonates were first fed and then starved,
starvation caused a large decrease in the abundance of both mRNAs. Conversely,
feeding, after a period of starvation, resulted in a substantial increase in
both mRNAs. The relative abundances of fatty acid synthase and malic enzyme
mRNAs correlated positively with relative rates of enzyme synthesis. Thus,
nutritional and hormonal regulation of the synthesis of these two 'lipogenic'
enzymes is exerted primarily at a pre-translational level. The abundance of
albumin mRNA decreased significantly between the 16th day of incubation and the
day of hatching but did not change thereafter in fed or starved chicks. The
relative stability of albumin mRNA levels after hatching attests to the
selectivity of the nutritional regulation of fatty acid synthase and malic
enzyme mRNAs. The decrease in albumin mRNA which occurred between 16 days of
incubation and hatching contrasts with the increase in albumin mRNA sequences
which occurred during late gestation in the fetal rat (20). High levels of
albumin in the chick embryo may be related to the lack of an analogue of
mammalian alpha-fetoprotein in birds.
- Language of Publication
- English
- Unique Identifier
- 85036274
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- MeSH Heading (Major)
- Fatty Acid Synthetase Complex|*GE; Liver|EM/*PH; Malate Dehydrogenase|*GE;
Serum Albumin|*GE
- MeSH Heading
- Animal; Animals, Newborn; Chick Embryo; Chickens|GE; Gene Expression
Regulation; RNA|GE; RNA, Messenger|GE; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0300-8177
- Country of Publication
- NETHERLANDS
Record 17 from database: MEDLINE
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- Title
- Regulation of the malic enzyme and fatty acid synthase genes in chick embryo
hepatocytes in culture: corticosterone and carnitine regulate responsiveness to
triiodothyronine.
- Author
- Roncero C; Goodridge AG
- Address
- Department of Biochemistry, University of Iowa, Iowa City 52242.
- Source
- Arch Biochem Biophys, 1992 Jun, 295:2, 258-67
- Abstract
- Triiodothyronine (T3) added to chick embryo hepatocytes between 20 and 68 h
of culture caused a 30- to 40-fold increase in malic enzyme activity. This T3
response decreased as a function of time; after 1 week in culture, a 48-h
incubation with T3 had no effect on hepatocyte malic enzyme activity. Neither
corticosterone nor carnitine had a significant effect on malic enzyme activity
in the absence of T3 at any time or on the response of malic enzyme to T3 during
the first 68 h of culture; both stimulated responsiveness to T3 subsequent to 68
h. The effects of corticosterone and carnitine on malic enzyme activity were
additive, suggesting different mechanisms. Corticosterone and carnitine
regulated abundance of malic enzyme mRNA. For corticosterone, at least, this
effect was due to regulation of transcription. Abundance of fatty acid synthase
mRNA was also stimulated by T3 in chick embryo hepatocytes in culture, and its
responsiveness to T3 decreased with time. Corticosterone and carnitine
stimulated responsiveness to T3 at times subsequent to 68 h. Corticosterone had
no effect on binding of T3 to nuclear receptors. Intracellular accumulation of
long-chain fatty acids or long-chain acyl-CoAs probably did not cause the loss
of responsiveness to T3 or the stimulation of that responsiveness by
corticosterone or carnitine because adding serum albumin (0.5%) or long-chain
fatty acids (0.25-0.5 mM) to the medium was without effect. Corticosterone and
carnitine may control the levels of other metabolic intermediates or protein
factors which, in turn, regulate the transcriptional response of the lipogenic
genes to T3.
- Language of Publication
- English
- Unique Identifier
- 92264722
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- MeSH Heading (Major)
- Carnitine|*PH; Corticosterone|*PH; Fatty Acid Synthetase Complex|*GE; Gene
Expression Regulation, Enzymologic|*; Liver|EM/*EN; Malate Dehydrogenase|*GE;
Triiodothyronine|*PH
- MeSH Heading
- Actins|GE; Animal; Blotting, Northern; Cells, Cultured; Chick Embryo;
Glyceraldehyde-3-Phosphate Dehydrogenases|GE; RNA, Messenger|GE; Support,
Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.; Transcription, Genetic
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0003-9861
- Country of Publication
- UNITED STATES
Record 18 from database: MEDLINE
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- Title
- Desaturation of polyunsaturated fatty acids in Mucor circinelloides and the
involvement of a novel membrane-bound malic enzyme.
- Author
- Kendrick A; Ratledge C
- Address
- Department of Applied Biology, University of Hull, England.
- Source
- Eur J Biochem, 1992 Oct, 209:2, 667-73
- Abstract
- 1. The component fatty acids of the endogenous phospholipids of microsomal
preparations of Mucor, when shaken at 30 degrees C, increased in both chain
length and in degree of unsaturation. The net effect was the production of
gamma-linolenic acid which, over 2 h, increased from 17% to 32% of total fatty
acids present. No further significant changes occurred after this time. 2. The
major site for desaturation/elongation reactions was at the sn-2 position of
PtdIns. PtdCho and PtdEtn were not implicated. 3. Of numerous metabolites and
cofactors added to the microsomes, only malate could prolong the
elongation/desaturation reactions for up to 6 h. This effect was shown to be due
to a membrane-associated malic enzyme [malate dehydrogenase (decarboxylating)
NADP+] with the NADPH produced being used in fatty-acid desaturation. 4. Kinetic
analysis of cytosolic and microsomal enzymes [both in 0.1% (mass/vol.) Chaps]
could not distinguish between them. However, when the microsomal malic enzyme
was dialysed to remove Chaps, it lost 90% of activity, although the cytosolic
malic enzyme lost only 20% activity. 5. The structural analogue of malate,
tartronic acid, which is an inhibitor of malic enzyme, also inhibited the
malate-induced stimulation of fatty-acyl group desaturation and elongation in
the microsomal membranes. 6. It is concluded that two distinct malic enzymes
exist, one soluble and one membrane bound, with similar active sites. Both have
different roles in the production of NADPH, for lipid metabolism. The former
will produce NADPH for fatty-acid biosynthesis whilst the latter produces NADPH
for fatty-acid desaturation.
- Language of Publication
- English
- Unique Identifier
- 93049312
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- MeSH Heading (Major)
- Fatty Acids, Unsaturated|*ME; Malate Dehydrogenase|*ME; Microsomes|*EN;
Mucor|*EN
- MeSH Heading
- Comparative Study; Cytochrome b5|ME; Cytochrome Reductases|ME; Cytosol|EN;
Enzyme Stability; Intracellular Membranes|EN; Kinetics; Substrate Specificity;
Support, Non-U.S. Gov't; Thermodynamics
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-2956
- Country of Publication
- GERMANY
Record 19 from database: MEDLINE
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- Title
- Simultaneous determination of organic acids and vitamin C in green beans by
liquid chromatography.
- Author
- Vazquez Oderiz ML; Vazquez Blanco ME; Lopez Hernandez J; Simal Lozano J;
Romero Rodriguez MA
- Address
- Universidad de Santiago de Compostela, Facultad de Farmacia, Departmento de
QuÆimica AnalÆitica, NutriciÆon y BromatologÆia, La CoruÃna, Spain.
- Source
- J AOAC Int, 1994 Jul, 77:4, 1056-9
- Abstract
- A method is described for determining and quantitating organic acids
(oxalic, malic, citric, and fumaric) and vitamin C by liquid chromatography with
a UV-visible detector that allows simultaneous monitoring at 2 wavelengths. The
method was applied to samples of green beans (Phaseolus vulgaris L.). Recoveries
were 97.8% for oxalic acid, 98.9% for malic acid, 98.7% for citric acid, 99.2%
for fumaric acid, and 98.5% for vitamin C. Method precisions (coefficients of
variation) were 1.7% for oxalic acid, 0.8% for malic acid, 0.9% for citric acid,
1.5% for fumaric acid, and 1.2% for vitamin C. Measurement precisions
(coefficients of variation) were 1.32% for oxalic acid, 0.33% for malic acid,
0.62% for citric acid, 1.01% for fumaric acid, and 0.39% for vitamin C. Limits
of detection were 0.025 mg/mL for oxalic acid, 0.022 mg/mL for malic acid, 0.024
mg/mL for citric acid, 1.0 x 10(-4) mg/mL for fumaric acid, and 2.7 x 10(-4)
mg/mL for vitamin C.
- Language of Publication
- English
- Unique Identifier
- 94348290
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- MeSH Heading (Major)
- Acids|*AN; Ascorbic Acid|*AN; Chromatography, Liquid|*MT; Legumes|*CH
- MeSH Heading
- Citrates|AN; Fumarates|AN; Malates|AN; Oxalates|AN; Reproducibility of
Results; Sensitivity and Specificity; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 1060-3271
- Country of Publication
- UNITED STATES
Record 20 from database: MEDLINE
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- Title
- Apple juice composition: sugar, nonvolatile acid, and phenolic profiles.
- Author
- Lee HS; Wrolstad RE
- Address
- Oregon State University, Department of Food Science and Technology,
Corvallis 97331.
- Source
- J Assoc Off Anal Chem, 1988 Jul, 71:4, 789-94
- Abstract
- Apples from Michigan, Washington, Argentina, Mexico, and New Zealand were
processed into juice; the 8 samples included Golden Delicious, Jonathan, Granny
Smith, and McIntosh varieties. Liquid chromatography was used for quantitation
of sugars (glucose, fructose, sucrose, and sorbitol), nonvolatile acids (malic,
quinic, citric, shikimic, and fumaric), and phenolics (chlorogenic acid and
hydroxymethylfurfural [HMF]). Other determinations included pH, 0Brix, and
L-malic acid. A number of compositional indices for these authentic juices,
e.g., chlorogenic acid content, total malic - L-malic difference, and the
HMF:chlorogenic ratio, were at variance with recommended standards. The phenolic
profile was shown to be particularly influenced by gelatin fining, with peak
areas decreasing by as much as 50%. The L-malic:total malic ratio serves as a
better index for presence of synthetic malic acid than does the difference
between the 2 determinations. No apparent differences in chemical composition
could be attributed to geographic origin.
- Language of Publication
- English
- Unique Identifier
- 88330681
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- MeSH Heading (Major)
- Beverages|*AN; Carbohydrates|*AN; Fruit|*AN; Phenols|*AN
- MeSH Heading
- Acids|AN; Chromatography, Liquid; Gelatin|DU; Indicators and Reagents;
Malates|AN; Reference Standards; Support, Non-U.S. Gov't; United States
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0004-5756
- Country of Publication
- UNITED STATES
Record 21 from database: MEDLINE
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- Title
- Derepressed utilization of L-malic acid and succinic acid by mutants of
Pachysolen tannophilus.
- Author
- Harrod CJ; Rodriguez SB; Thornton RJ
- Address
- Department of Microbiology and Genetics, Massey University, Palmerston
North, New Zealand.
- Source
- J Ind Microbiol Biotechnol, 1997 Jun, 18:6, 379-83
- Abstract
- Utilization of the tricarboxylic acid (TCA) cycle intermediates, L-malic
acid and succinic acid, by the yeast Pachysolen tannophilus is repressed in the
presence of glucose. Strains of P. tannophilus containing mutations in two
hexokinases and a glucokinase were characterized for growth on glucose plus
L-malic acid or succinic acid. Increased specific utilization rates of malic
acid and succinic acid in the presence of glucose were observed in mutants
containing a lesion in hexokinase A, an enzyme associated with catabolite
repression. Such derepressed mutants may have application in winemaking in which
utilization of a major grape acid, L-malic acid, is often desirable for acidity
reduction.
- Language of Publication
- English
- Unique Identifier
- 97391261
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- MeSH Heading (Major)
- Malates|*ME; Saccharomycetales|*ME; Succinates|*ME
- MeSH Heading
- Glucose|ME; Hydrogen-Ion Concentration; Mutation; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 1367-5435
- Country of Publication
- ENGLAND
Record 22 from database: MEDLINE
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- Title
- Production of L-malic acid via biocatalysis employing wild-type and
respiratory-deficient yeasts.
- Author
- Wang X; Gong CS; Tsao GT
- Address
- Laboratory of Renewable Resources Engineering, Potter Engineering Center,
Purdue University, West Lafayette, IN 47907, USA.
- Source
- Appl Biochem Biotechnol, 1998 Spr, 70-72:, 845-52
- Abstract
- The yeast Saccharomyces cerevisiae has been used to efficiently produce
L-malic acid from fumaric acid. Fumarase is responsible for the reversible
conversion of fumaric and L-malic acids in the TCA cycle. To investigate the
function of mitochondrial and cytoplasmic fumarase isoenzymes in L-malic acid
bioconversion, a wild-type strain and a cytoplasmic respiratory-deficient mutant
devoid of functional mitochondria were employed. The mutant strain, which only
contained the cytoplasmic fumarase, was still functional in fumaric acid to
L-malic acid bioconversion However, its specific conversion rate was much lower
(0.20 g/g.h) than that of the wild-type strain (0.55 g/g.h).
- Language of Publication
- English
- Unique Identifier
- 98290870
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- MeSH Heading (Major)
- Malates|*CS; Saccharomyces cerevisiae|GE/*ME
- MeSH Heading
- Catalysis; Cytoplasm|EN; Dyes; Fermentation; Fumarate Hydratase|CH;
Fumarates|CH; Mitochondria|EN; Oxygen Consumption|GE; Stereoisomerism; Support,
U.S. Gov't, Non-P.H.S.; Tetrazolium Salts
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0273-2289
- Country of Publication
- UNITED STATES
Record 23 from database: MEDLINE
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- Title
- Molecular analysis of the malic enzyme gene (mae2) of Schizosaccharomyces
pombe.
- Author
- Viljoen M; Subden RE; Krizus A; Van Vuuren HJ
- Address
- Department of Microbiology, University of Stellenbosch, South Africa.
- Source
- Yeast, 1994 May, 10:5, 613-24
- Abstract
- Sequence analysis of a 4.6-kb HindIII fragment containing the malic enzyme
gene (mae2) of Schizosaccharomyces pombe, revealed the presence of an open
reading frame of 1695 nucleotides, coding for a 565 amino acid polypeptide. The
mae2 gene is expressed constitutively and encodes a single mRNA transcript of
2.0 kb. The mae2 gene was mapped on chromosome III by chromoblotting. The coding
region and inferred amino acid sequence showed significant homology with 12
malic enzyme genes and proteins from widely different origins. Eight highly
homologous regions were found in these malic enzymes, suggesting that they
contain functionally conserved amino acid sequences that are indispensable for
activity of malic enzymes. Two of these regions have previously been reported to
be NAD- and NADP-binding sites.
- Language of Publication
- English
- Unique Identifier
- 95028159
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- MeSH Heading (Major)
- Genes, Fungal|*; Malate Dehydrogenase|*GE/ME; Schizosaccharomyces|EN/*GE
- MeSH Heading
- Amino Acid Sequence; Base Sequence; Blotting, Northern; Chromosome Mapping;
DNA Probes; Molecular Sequence Data; NAD; NADP; Sequence Analysis, DNA; Sequence
Homology, Amino Acid; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0749-503X
- Country of Publication
- ENGLAND
Record 24 from database: MEDLINE
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- Title
- Affinity cleavage at the putative metal-binding site of pigeon liver malic
enzyme by the Fe(2+)-ascorbate system.
- Author
- Wei CH; Chou WY; Huang SM; Lin CC; Chang GG
- Address
- Graduate Institutes of Life Sciences and Biochemistry, National Defense
Medical Center, Taipei, Taiwan, Republic of China.
- Source
- Biochemistry, 1994 Jun, 33:25, 7931-6
- Abstract
- Pigeon liver malic enzyme was rapidly inactivated by micromolar
concentrations of ferrous sulfate in the presence of ascorbate at neutral pH and
0 or 25 degrees C. Omitting the ascorbate or replacing the ferrous ion with
manganese ion did not lead to any inactivation. Manganese, magnesium, zinc,
cobalt, or calcium ion at 200 molar excess over ferrous ion offered complete
protection of the enzyme from Fe(2+)-induced inactivation. Ni2+ provided partial
protection, while Ba2+ or imidazole was ineffective in protection. Addition of 4
mM Mn2+ or 5 mM EDTA into a partially modified enzyme stopped further
inactivation of the enzyme. Inclusion of substrates (L-malate or NADP+, singly
or in combination) in the incubation mixture did not affect the inactivation
rate. The enzyme inactivation was demonstrated to be followed by protein
cleavage. Native pigeon liver malic enzyme had a subunit M(r) of 65,000. The
inactivated enzyme with residual activity of only 0.3% was cleaved into two
fragments with M(r) of 31,000 and 34,000, respectively. The cleavage site was
identified as the peptide bond between Asp258 and Ile259. Native pigeon liver
malic enzyme was blocked at the N-terminus. Cleavage at the putative
metal-binding site exposed a new N-terminus, which was identified to be at the
34-kDa fragment containing the C-terminal half of original sequence 259-557. Our
results indicated that Fe2+ catalyzed a specific oxidation of pigeon liver malic
enzyme at Asp258 and/or some other essential amino acid residues that caused
enzyme inactivation. The modified enzyme was then affinity cleaved at the
Mn(2+)-binding site.
- Language of Publication
- English
- Unique Identifier
- 94281225
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- MeSH Heading (Major)
- Ascorbic Acid|*CH; Ferrous Compounds|*CH; Malate Dehydrogenase|AI/*CH;
Manganese|*CH; Metalloproteins|*CH
- MeSH Heading
- Amino Acid Sequence; Animal; Aspartic Acid|CH; Comparative Study; Liver|EN;
Molecular Sequence Data; Pigeons; Sequence Alignment; Sequence Homology, Amino
Acid; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2960
- Country of Publication
- UNITED STATES
Record 25 from database: MEDLINE
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- Title
- Cloning and expression of pigeon liver cytosolic NADP(+)-dependent malic
enzyme cDNA and some of its abortive mutants.
- Author
- Chou WY; Huang SM; Liu YH; Chang GG
- Address
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan,
Republic of China.
- Source
- Arch Biochem Biophys, 1994 Apr, 310:1, 158-66
- Abstract
- A full-length 1927-base-pair cDNA of pigeon liver malic enzyme was obtained
by utilizing the screening of the cDNA library and polymerase chain reaction
techniques. The cDNA contained one open reading frame coding for 557 amino acid
residues, flanked by 86 and 167 nucleotides at the 5' and 3' termini,
respectively, and was successfully cloned and expressed in Escherichia coli
cells. Functionally active recombinant malic enzyme was purified from the cells.
This recombinant enzyme has a Km value for L-malate of 160 +/- 30 microM, which
is almost identical to that for the natural enzyme (150 +/- 17 microM). The Km
value for Mn2+ (4.2 +/- 0.3 microM) is higher than that for the natural pigeon
malic enzyme (1.4 +/- 0.2 microM), while the Km value for NADP+ (3.8 +/- 0.3
microM) is lower than that for the natural enzyme (10.8 +/- 0.1 microM). The
catalytic constant (kcat) for the recombinant enzyme is decreased by 3.6-fold,
but the substrate inhibition constant for L-malate is increased by about
40-fold. Change in the quaternary structure of the recombinant enzyme was
revealed in the pH perturbation examination. A truncated pigeon liver malic
enzyme, lacking the first 13 amino acid residues, and a recombinant protein,
mutated at F19S, N250S, and L353Q, showed no enzymatic activity. Both abortive
recombinant mutant proteins were still able to bind with 2',5'-ADP agarose;
however, the fluorescence emission spectrum of the protein bound NADPH did not
show a blue shift as the natural enzyme. In accordance with these observations,
we suggest that the adenosine 2',5'-bisphosphate binding domain of the NADP+
binding site in the beta alpha beta motif may still be retained in these mutant
proteins. However, the local hydrophobic environment for the binding of the
nicotinamide moiety of the coenzyme molecule may be altered. Therefore, the lack
of catalytic activity of the mutant proteins could be attributed to an improper
orientation of the bound NADP+.
- Language of Publication
- English
- Unique Identifier
- 94213482
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- MeSH Heading (Major)
- Cytosol|*EN; Liver|*EN; Malate Dehydrogenase|*GE/ME
- MeSH Heading
- Adenosine Diphosphate|ME; Amino Acid Sequence; Animal; Base Sequence;
Chromatography, Affinity; Cloning, Molecular; Comparative Study; DNA Probes;
DNA, Complementary|GE; Escherichia coli|GE; Gene Library; Molecular Sequence
Data; Mutation; NADP|ME; Pigeons; Protein Conformation; Recombinant Proteins|BI;
Sequence Analysis, DNA; Sequence Homology, Amino Acid; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0003-9861
- Country of Publication
- UNITED STATES
Record 26 from database: MEDLINE
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- Title
- Plant mitochondrial NAD+-dependent malic enzyme. cDNA cloning, deduced
primary structure of the 59- and 62-kDa subunits, import, gene complexity and
expression analysis.
- Author
- Winning BM; Bourguignon J; Leaver CJ
- Address
- Department of Plant Sciences, University of Oxford, United Kingdom.
- Source
- J Biol Chem, 1994 Feb, 269:7, 4780-6
- Abstract
- The 59- and 62-kDa subunits of the mitochondrial NAD+-dependent malic enzyme
(EC 1.1.1.39) were purified from Solanum tuberosum L. (potato). NH2-terminal and
internal amino acid sequence information was used to identify cDNAs encoding the
two subunits. Comparison of the nucleotide sequences revealed that the subunits
have 60% identity at the DNA level and 65% identity at the deduced amino acid
level, implying that they are derived from a common ancestral gene. The plant
NAD+-dependent malic enzymes belong to a family of related enzymes, including
cytosolic and chloroplastic NADP+-dependent malic enzymes (EC 1.1.1.40) and
bacterial NAD+-dependent malic enzymes (EC 1.1.1.38). The cDNAs were transcribed
and translated in vitro and the resultant polypeptides imported into isolated
mitochondria and shown to be processed. Southern blot analysis of potato genomic
DNA revealed a simple pattern of hybridization for both subunits, indicating a
simple gene structure or small number of genes encoding the two subunits.
Northern blot analysis of RNA from a range of potato tissues has shown that the
steady state levels for the two subunits are equivalent, suggesting that they
are coordinately expressed.
- Language of Publication
- English
- Unique Identifier
- 94148921
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- MeSH Heading (Major)
- Gene Expression|*; Malate Dehydrogenase|*BI/*GE/IP; Mitochondria|*EN;
Potatoes|*EN/GE
- MeSH Heading
- Amino Acid Sequence; Animal; Base Sequence; Blotting, Northern; Blotting,
Southern; Cloning, Molecular; Comparative Study; DNA|BI/IP; DNA,
Complementary|ME; Genes, Plant; Human; Macromolecular Systems; Molecular
Sequence Data; NAD|ME; Sequence Homology, Amino Acid; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 27 from database: MEDLINE
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- Title
- Human NAD(+)-dependent mitochondrial malic enzyme. cDNA cloning, primary
structure, and expression in Escherichia coli.
- Author
- Loeber G; Infante AA; Maurer Fogy I; Krystek E; Dworkin MB
- Address
- Ernst Boehringer Institut, Vienna, Austria.
- Source
- J Biol Chem, 1991 Feb, 266:5, 3016-21
- Abstract
- Mitochondrial NAD(+)-dependent malic enzyme (EC 1.1.1.40) is expressed in
rapidly proliferating cells and tumor cells, where it is probably linked to the
conversion of amino acid carbon to pyruvate. In this paper, we report the cDNA
cloning, amino acid sequence, and expression in Escherichia coli of functional
human NAD(+)-dependent mitochondrial malic enzyme. The cDNA is 1,923 base pairs
long and contains an open reading frame coding for a 584-amino acid protein. The
molecular mass is 65.4 kDa for the unprocessed precursor protein. Comparison of
the amino acid sequence of the human protein with the published
NADP(+)-dependent mammalian cytosolic or plant chloroplast malic enzymes reveals
highly conserved regions interrupted with long stretches of amino acids without
significant homology. Expression of the processed protein in E. coli yielded an
enzyme with the same kinetic and allosteric properties as malic enzyme purified
from human cells.
- Language of Publication
- English
- Unique Identifier
- 91131600
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- MeSH Heading (Major)
- Escherichia coli|*GE; Gene Expression Regulation, Bacterial|*; Malate
Dehydrogenase|*GE; Mitochondria|*EN; NAD|*ME
- MeSH Heading
- Amino Acid Sequence; Animal; Chromatography, High Pressure Liquid; Cloning,
Molecular; DNA|GE; Electrophoresis, Polyacrylamide Gel; Human; Mice; Molecular
Sequence Data; Plants|GE; Rats; Sequence Homology, Nucleic Acid; Trypsin
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 28 from database: MEDLINE
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- Title
- Nutritional regulation and tissue-specific expression of the malic enzyme
gene in the chicken. Transcriptional control and chromatin structure.
- Author
- Ma XJ; Salati LM; Ash SE; Mitchell DA; Klautky SA; Fantozzi DA; Goodridge AG
- Address
- Department of Biochemistry, University of Iowa, Iowa City 52242.
- Source
- J Biol Chem, 1990 Oct, 265:30, 18435-41
- Abstract
- Refeeding starved chicks causes a 25- to 50-fold increase in the level of
malic enzyme mRNA in liver. To define the regulated steps, we measured
transcriptional activity of the malic enzyme gene using the nuclear run-on assay
and a variety of DNA probes specific to the malic enzyme gene. Refeeding starved
chicks stimulated transcription of the malic enzyme gene in liver by 40- to
50-fold. An increased transcription rate was detectable at 1.5 h, was maximal at
3 h, and remained high at 24 h of refeeding. The level of nuclear precursor RNA
for malic enzyme assessed by hybridization with intron-specific probes was high
in liver of refed birds, and barely detectable in that of starved birds. These
results indicate that nutritional regulation of the level of malic enzyme mRNA
is transcriptional. Low levels of malic enzyme mRNA in brain, kidney, and heart
correlated well with low rates of transcription of the malic enzyme gene in
these tissues. In contrast to liver, neither the rate of transcription nor the
steady-state level of malic enzyme mRNA was affected by refeeding starved birds.
A series of DNase I-hypersensitive sites were located within 4000 base pairs
upstream of the transcription start site of the malic enzyme gene in liver. The
DNase I-hypersensitive region extending from the start of transcription to 400
base pairs upstream was much more pronounced in the refed state than in the
starved state. This change in DNase I hypersensitivity followed the same time
course as increased transcription of the malic enzyme gene. This DNase
I-hypersensitive region also was present at low intensity in kidney and heart
independently of nutritional state. The three constitutive DNase
I-hypersensitive sites further upstream were present in liver but not in kidney
or heart.
- Language of Publication
- English
- Unique Identifier
- 91009340
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- MeSH Heading (Major)
- Chickens|*GE; Chromatin|*UL; Gene Expression Regulation, Enzymologic|*;
Malate Dehydrogenase|*GE
- MeSH Heading
- Animal; Animal Nutrition; Blotting, Northern; Cell Nucleus|ME;
Deoxyribonuclease I|PD; DNA|GE; Genes, Structural; Kidney|PH; Liver|PH; Nucleic
Acid Precursors|ME; Regulatory Sequences, Nucleic Acid; Restriction Mapping;
Support, U.S. Gov't, P.H.S.; Tissue Distribution; Transcription, Genetic
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 29 from database: MEDLINE
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- Title
- A simple plate-assay for the screening of L-malic acid producing
microorganisms.
- Author
- Peleg Y; Rokem JS; Goldberg I
- Address
- Department of Applied Microbiology, Hebrew University-Hadassah Medical
School, Jerusalem, Israel.
- Source
- FEMS Microbiol Lett, 1990 Feb, 55:3, 233-6
- Abstract
- A simple plate-assay has been developed to screen microorganisms for L-malic
acid production. Acid producing organisms were identified, after microbial
colony growth on media containing glucose or fumaric acid as sole carbons
sources, by formation of a dark halo of formazan. The halo was observed when the
plate was covered with a soft agar overlay containing NAD(+)-malate
dehydrogenase, NAD+, phenazine methosulfate (PMS) and
3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT). The assay
developed is simple, specific for L-malic acid and therefore can be used to
identify L-malic acid producing filamentous fungi using glucose as carbon source
(e.g. Aspergillus strains). The assay is also applicable for screening bacteria
with high fumarase activity, able to convert fumaric acid to L-malic acid.
- Language of Publication
- English
- Unique Identifier
- 90215177
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- MeSH Heading (Major)
- Aspergillus|*ME; Bacteria|*ME; Malates|*ME; Microbiological Techniques|*
- MeSH Heading
- Culture Media; Fumarates|ME; Isoenzymes; Malate Dehydrogenase
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0378-1097
- Country of Publication
- NETHERLANDS
Record 30 from database: MEDLINE
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- Title
- L-malic-acid permeation in resting cells of anaerobically grown
Saccharomyces cerevisiae.
- Author
- Salmon JM
- Address
-
- Source
- Biochim Biophys Acta, 1987 Jul, 901:1, 30-4
- Abstract
- The study of permeation of L-malic acid in cells of Saccharomyces cerevisiae
at pH 3.0 was carried out with (U-14C)-labelled L-malic acid. Resting cells were
used in these experiments. They were previously anaerobically grown on glucose.
This study showed that this transport is the result of two competitive
mechanisms, one for the uptake and one for the efflux. The uptake mechanism
seems to be a simple diffusion of the L-malic acid in a non-dissociated form.
The efflux mechanism seems to be an active transport of L-malic acid that is
very dependent on the temperature. At the steady state, the result of uptake and
efflux mechanisms leads to an intracellular concentration which is twice or
three times the extracellular concentration.
- Language of Publication
- English
- Unique Identifier
- 87242453
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- MeSH Heading (Major)
- Cell Membrane Permeability|*; Malates|*ME; Saccharomyces cerevisiae|*ME
- MeSH Heading
- Biological Transport|DE; Dicyclohexylcarbodiimide|PD; Dinitrophenols|PD;
Kinetics; Temperature
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3002
- Country of Publication
- NETHERLANDS
Record 31 from database: MEDLINE
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- Title
- The chicken malic enzyme gene: structural organization and identification of
triiodothyronine response elements in the 5'-flanking DNA.
- Author
- Hodnett DW; Fantozzi DA; Thurmond DC; Klautky SA; MacPhee KG; Estrem ST; Xu
G; Goodridge AG
- Address
- Department of Biochemistry, University of Iowa, Iowa City 52242, USA.
- Source
- Arch Biochem Biophys, 1996 Oct, 334:2, 309-24
- Abstract
- In vivo, feeding stimulates and starvation inhibits transcription of the
malic enzyme gene. In chick-embryo hepatocytes in culture, triiodothyronine (T3)
stimulates and glucagon inhibits transcription of this gene. As a first step in
the characterization of the involved regulatory mechanisms, fragments of genomic
DNA spanning the structural and 5'-flanking regions of the chicken malic enzyme
gene were cloned. The coding region of the gene is organized into 14 exons and
13 introns and is greater than 106 kb in length. The size of the gene, the
number and lengths of the exons, and positions at which introns are inserted
into the coding regions are virtually identical in the chicken and rat genes.
When transiently transfected into chick-embryo hepatocytes, 5800 bp of
5'-flanking DNA conferred T3 responsiveness to a linked chloramphenicol
acetyltransferase (CAT) reporter gene. Using deletion and site-specific
mutations of 5'-flanking DNA, we identified a complex T3 response unit that
contains one major T3 response element (T3RE) and several minor ones. The major
element contains two degenerate copies of the hexamer, RGGWMA, separated by 4 bp
and was a strong repressor in the absence of ligand. Endogenous levels of T3
receptor are sufficient to allow the T3 response elements in the upstream region
of the malic enzyme gene to confer responsiveness to T3, suggesting that they
are physiologically relevant.
- Language of Publication
- English
- Unique Identifier
- 97056061
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- MeSH Heading (Major)
- Chickens|*GE; Malate Dehydrogenase|*BI/*GE; Regulatory Sequences, Nucleic
Acid|*/DE; Triiodothyronine|*PD
- MeSH Heading
- Animal; Base Sequence; Cells, Cultured; Chick Embryo; Chloramphenicol
O-Acetyltransferase|BI; Liver|ME; Molecular Sequence Data; Mutagenesis,
Site-Directed; Rats; Recombinant Fusion Proteins|BI; Repetitive Sequences,
Nucleic Acid; Restriction Mapping; Sequence Deletion; Sequence Homology, Nucleic
Acid; Support, U.S. Gov't, P.H.S.; Transfection
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0003-9861
- Country of Publication
- UNITED STATES
Record 32 from database: MEDLINE
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- Title
- Sequence of a malic enzyme gene of Giardia lamblia.
- Author
- Sánchez LB; Hashimoto T; Müller M
- Address
- Rockefeller University, New York, NY 10021, USA.
sanchel@rockvax.rockefeller.edu
- Source
- Mol Biochem Parasitol, 1996 Nov, 82:2, 145-51
- Abstract
- The nucleotide sequence and predicted amino acid sequence of malate
dehydrogenase (decarboxylating) or malic enzyme (EC 1.1.1.40) of the
amitochondriate protist Giardia lamblia were determined. The overall amino acid
identity with malic enzyme sequences from other eukaryotes was between 34 and
39%. Functional domains previously defined in other malic enzymes, the malate-,
the ADP- and the NAD(P)-binding domains, were present also in the G. lamblia
sequence. In phylogenetic reconstructions, the G. lamblia sequence is part of
the eukaryotic clade, but its relative position versus the other early branches
of the eukaryotic tree (Trichomonas vaginalis hydrogenosome and plant
mitochondria) cannot be firmly established. The results indicate, however, a
long, independent evolutionary past of this enzyme.
- Language of Publication
- English
- Unique Identifier
- 97101863
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- MeSH Heading (Major)
- Genes, Protozoan|*; Giardia lamblia|EN/*GE; Malate Dehydrogenase|CL/*GE
- MeSH Heading
- Amino Acid Sequence; Animal; Binding Sites; Comparative Study; Evolution,
Molecular; Likelihood Functions; Molecular Sequence Data; Phylogeny; Sequence
Analysis; Sequence Homology, Amino Acid; Support, Non-U.S. Gov't; Support, U.S.
Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0166-6851
- Country of Publication
- NETHERLANDS
Record 33 from database: MEDLINE
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- Title
- Swine cytosolic malic enzyme: cDNA cloning, sequencing, and localization.
- Author
- Nunes M; Lahbib Mansais Y; Geffrotin C; Yerle M; Vaiman M; Renard C
- Address
- Laboratoire mixte INRA-CEA de Radiobiologie appliquÆee, centre de recherche
INRA de Jouy-en-Josas, 78352 France.
- Source
- Mamm Genome, 1996 Nov, 7:11, 815-21
- Abstract
- A highly significant genetic association has been found between some alleles
of the swine Major Histocompatibility Complex SLA (Swine Leukocyte Antigen
genetic complex) and the cytosolic malic enzymatic activity level in muscles.
The aim of this study was to find out whether this genetic association was due
to a close linkage of the SLA region and the gene coding for the enzyme. Since
no swine cytosolic malic enzyme sequence (ME1) was available, we isolated
several overlapping fragments that spanned the almost entire malic enzyme
transcript both by screening of a swine cDNA library and by RT-PCR. The results
indicated the existence of two transcripts of 2. 0 and 3.1 kb, which probably
correspond to two alternative forms of one gene. The sequence of the transcript
was highly similar to the other published mammalian cytosolic NADP+-dependent
malic enzyme cDNA, especially within the four functional domains. Two major
bands at 3.7 and 2.4 kb were detected on Northern blots containing the RNA from
25 tissues from fetuses and adult pigs. A high expression level was found in the
adrenal gland, muscle, liver, and peripheral nerves. The analysis of malic
enzyme RFLPs in five SLA informative families revealed an independent
segregation of the ME1 gene from the SLA region. In situ hybridization results
localized the cytosolic malic enzyme on the swine Chromosome (Chr) 1p1.2, except
that the association between SLA and the malic enzyme activity level was due to
a physical genetic linkage. Thus, the mechanisms underlying this association
remain to be elucidated.
- Language of Publication
- English
- Unique Identifier
- 97032530
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- MeSH Heading (Major)
- Chromosome Mapping|*; Malate Dehydrogenase|BI/*CH/*GE; Swine|*GE
- MeSH Heading
- Amino Acid Sequence; Animal; Base Sequence; Cloning, Molecular; Comparative
Study; Cytosol; DNA Primers; DNA Probes; DNA, Complementary; Female; Human;
Male; Mitochondria|EN; Molecular Sequence Data; Polymerase Chain Reaction;
Polymorphism, Restriction Fragment Length; Rats; Restriction Mapping; Sequence
Homology, Amino Acid
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0938-8990
- Country of Publication
- UNITED STATES
Record 34 from database: MEDLINE
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- Title
- Nonidentity of the cDNA sequence of human breast cancer cell malic enzyme to
that from the normal human cell.
- Author
- Chou WY; Huang SM; Chang GG
- Address
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan,
Republic of China.
- Source
- J Protein Chem, 1996 Apr, 15:3, 273-9
- Abstract
- A cDNA coding for human breast cancer cell cytosolic NADP(+)-dependent malic
enzyme was obtained. This cDNA is composed of a length of 2084 base pairs, with
1698 base pairs coding for 565 amino acid residues and a length of 386 base
pairs representing a 3'-noncoding region. Comparing this nucleotide sequence
with that from the normal human tissue [Loeber, G., Dworkin, M. B., Infante, A.,
and Ahorn, H. (1994), FEBS Lett. 344, 181-186] reveals that three nucleotides in
the open reading frame and the length of 3'-noncoding region of the cDNA are
different. One of the changes results in a substitution of serine at position
438 for proline, which, however, may not cause significant changes in the
predicted secondary structure. A partial cDNA lacking the first 84 nucleotides
in the open reading frame was successfully cloned and expressed functionally in
Escherichia coli cells. Its Km value for L-malate (1.21 +/- 0.11 mM) is four
times higher than that for the natural human breast cancer cell malic enzyme
(0.29 +/- 0.04 mM) but similar to that for the full-length recombinant enzyme
(1.06 +/- 0.07 mM). The Km values for Mn2+ and NADP+ (0.26 +/- 0.03 and 0.97 +/-
0.4 microM, respectively) are similar to those for the natural enzyme (0.12 +/-
0.02 and 1.9 +/- 0.3 microM, respectively) or the recombinant wild-type enzyme
(0.56 +/- 0.04 and 0.44 +/- 0.02 microM, respectively). A recombinant pigeon
liver malic enzyme without the first 13 amino acid residues was used for
comparison. The Km values for L-malate and Mn2+ of the truncated enzyme (11.2
+/- 0.9 mM and 61.2 +/- 4.6 microM, respectively) are over 40 times larger than
those for the natural pigeon liver malic enzyme (0.21 +/- 0.02 mM and 1.06 +/-
0.08 microM, respectively) or the recombinant wild-type enzyme (0.25 +/- 0.01 mM
and 1.48 +/- 0.05 microM, respectively). We suggest that the N-terminus of malic
enzyme may be required for the substrate binding during the catalytic cycle.
- Language of Publication
- English
- Unique Identifier
- 96397682
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- MeSH Heading (Major)
- Breast Neoplasms|*EN/PA; Malate Dehydrogenase|CH/*GE/IP/ME
- MeSH Heading
- Amino Acid Sequence; Animal; Base Sequence; Blotting, Northern; Cloning,
Molecular; Comparative Study; Cytosol|CH/EN; DNA Probes; DNA, Complementary|CH;
DNA, Neoplasm|CH; Female; Human; Kinetics; Mice; Molecular Sequence Data;
Pigeons; Plasmids; Rats; Recombinant Proteins|CH/GE/IP/ME; RNA, Neoplasm|AN/GE;
Sequence Alignment; Sequence Analysis, DNA; Support, Non-U.S. Gov't; Tumor
Cells, Cultured
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0277-8033
- Country of Publication
- UNITED STATES
Record 35 from database: MEDLINE
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- Title
- Overexpression of the alpha-thyroid hormone receptor in avian cell lines.
Effects on expression of the malic enzyme gene are selective and cell-specific.
- Author
- Hillgartner FB; Chen W; Goodridge AG
- Address
- Department of Biochemistry, University of Iowa, Iowa City 52242.
- Source
- J Biol Chem, 1992 Jun, 267:17, 12299-306
- Abstract
- The role of the alpha-thyroid hormone receptor (TR alpha) in regulation of
transcription of the gene for chicken malic enzyme was analyzed in fibroblast
cell lines normally unresponsive to triiodothyronine (T3). The gene for this
transcription factor was introduced stably and overexpressed using a
replication-competent retroviral vector. In chick embryo fibroblasts (CEF),
overexpression of TR alpha decreased malic enzyme activity by 90% in the absence
of T3. Addition of T3 almost completely restored malic enzyme activity to the
level of similarly treated control CEF infected with virus lacking TR alpha.
These TR alpha-induced changes in malic enzyme activity were mediated by
alterations in transcription of the malic enzyme gene. Similar results were
obtained when transcriptional activity of TR alpha was analyzed using a
transient co-transfection system. Thus, the unliganded TR alpha is a
transcriptional repressor of the malic enzyme gene; binding of T3 to the
receptor abolishes this repression. In contrast, stable overexpression of TR
alpha in QT6 cells had no effect on malic enzyme expression in the absence or
presence of T3. Nuclear T3 binding was equally high in CEF and QT6 cells
overexpressing TR alpha. These findings suggest that cell-specific factors
control the ability of TR alpha to regulate the malic enzyme gene.
Overexpression of TR alpha in CEF had no effect on the expression of fatty acid
synthase and acetyl-CoA carboxylase, lipogenic enzymes that are stimulated by T3
in hepatocytes in culture. Thus, gene-specific factors also may control the
transcriptional activity of TR alpha.
- Language of Publication
- English
- Unique Identifier
- 92291117
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- MeSH Heading (Major)
- Gene Expression Regulation, Enzymologic|*; Malate Dehydrogenase|*GE;
Receptors, Thyroid Hormone|GE/*PH
- MeSH Heading
- Acetyl-CoA Carboxylase|GE; Actins|GE; Animal; Cell Line; Chick Embryo; DNA
Probes; Fatty Acid Synthetase Complex|GE; Fibroblasts|EN;
Glyceraldehyde-3-Phosphate Dehydrogenases|GE; Proto-Oncogene Proteins|GE; RNA,
Messenger|ME; Support, U.S. Gov't, P.H.S.; Transcription, Genetic;
Triiodothyronine|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 36 from database: MEDLINE
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- Title
- Triiodothyronine-induced accumulations of malic enzyme, fatty acid synthase,
acetyl-coenzyme A carboxylase, and their mRNAs are blocked by protein kinase
inhibitors. Transcription is the affected step.
- Author
- Swierczynski J; Mitchell DA; Reinhold DS; Salati LM; Stapleton SR; Klautky
SA; Struve AE; Goodridge AG
- Address
- Department of Biochemistry, University of Iowa, Iowa City 52242.
- Source
- J Biol Chem, 1991 Sep, 266:26, 17459-66
- Abstract
- Addition of triiodothyronine (T3) to chick-embryo hepatocytes in culture
causes increased accumulations of malic enzyme, fatty acid synthase, acetyl-CoA
carboxylase and their mRNAs. H-8 and other protein kinase inhibitors inhibited
the T3-induced accumulations of these lipogenic enzymes and their mRNAs but had
no effect on the activities of 6-phosphogluconate dehydrogenase and isocitrate
dehydrogenase, enzymes not induced by T3 in chick-embryo hepatocytes. H-8 also
had no effect on the activities of malic enzyme, fatty acid synthase, and
acetyl-CoA carboxylase in hepatocytes not treated with T3. Synthesis of soluble
protein, levels of mRNAs for beta-actin and glyceraldehyde-3-phosphate
dehydrogenase, and induction of metallothionein mRNA by Zn2+ were unaffected by
H-8 at concentrations that inhibited the T3-induced accumulation of lipogenic
enzymes and their mRNAs. H-8 inhibited T3-induced transcription of the genes for
both malic enzyme and fatty acid synthase but had little effect on transcription
of the beta-actin or glyceraldehyde-3-phosphate dehydrogenase genes or on total
RNA synthesis in isolated nuclei. H-8 also had no effect on binding of T3 to its
nuclear receptor. In isolated nuclei, H-8 inhibited phosphorylation of total
protein by 15-20%. Phosphorylation of only one major protein was consistently
and substantially inhibited, indicating that the effect of H-8 was selective.
These results suggest that on-going protein phosphorylation is required
specifically for stimulation of transcription of the lipogenic genes by T3.
- Language of Publication
- English
- Unique Identifier
- 91373369
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- MeSH Heading (Major)
- Acetyl-CoA Carboxylase|GE/*ME; Fatty Acid Synthetase Complex|GE/*ME; Malate
Dehydrogenase|GE/*ME; Protein Kinases|*AI; Transcription, Genetic|*DE;
Triiodothyronine|*AI/PD
- MeSH Heading
- Alkaloids|PD; Animal; Cells, Cultured; Chick Embryo; Isoquinolines|PD;
Liver|EN; Metallothionein|GE; RNA, Messenger|ME; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 37 from database: MEDLINE
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- Title
- Primary structure of the maize NADP-dependent malic enzyme.
- Author
- Rothermel BA; Nelson T
- Address
- Biology Department, Yale University, New Haven, Connecticut 06511.
- Source
- J Biol Chem, 1989 Nov, 264:33, 19587-92
- Abstract
- Chloroplast-localized NADP-dependent malic enzyme (EC 1.1.1.40) (NADP-ME)
provides a key activity for the carbon 4 fixation pathway. In maize, nuclear
encoded NADP-ME is synthesized in the cytoplasm as a precursor with a transit
peptide that is removed upon transport into the chloroplast stroma. We present
here the complete nucleotide sequence for a 2184-base pair full-length maize
NADP-ME cDNA. The predicted precursor protein is 636 amino acids long with a Mr
of 69,800. There is a strong codon bias found in the amino-terminal portion of
NADP-ME that is present in genes for the other enzymes of the C-4 photosynthetic
pathway. The NADP-ME transit peptide has general features common to other known
chloroplast stroma transit peptides. Comparison of mature maize NADP-ME to the
amino acid sequences of known malic enzymes shows two conserved
dinucleotide-binding sites. There is a third highly conserved region of unknown
function. On the basis of amino acid sequence similarity, the maize
chloroplastic enzyme is more closely related to eukaryotic cytosolic isoforms of
malic enzyme than to prokaryotic isoforms. We discuss the functional and
evolutionary relationship between the chloroplastic and cytosolic forms of
NADP-ME.
- Language of Publication
- English
- Unique Identifier
- 90062054
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- MeSH Heading (Major)
- Malate Dehydrogenase|*GE; Plants|*EN/GE
- MeSH Heading
- Amino Acid Sequence; Animal; Base Sequence; Chloroplasts|EN; Comparative
Study; Corn|EN/GE; DNA|GE; Genes, Structural, Plant; Mice; Molecular Sequence
Data; Rats; Restriction Mapping; Sequence Homology, Nucleic Acid; Support, U.S.
Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 38 from database: MEDLINE
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- Title
- Tolerance of acid-adapted and non-adapted Escherichia coli O157:H7 cells to
reduced pH as affected by type of acidulant.
- Author
- Deng Y; Ryu JH; Beuchat LR
- Address
- Department of Food Science and Technology, University of Georgia, Griffin
30223-1797, USA.
- Source
- J Appl Microbiol, 1999 Feb, 86:2, 203-10
- Abstract
- A study was carried out to determine if three strains of Escherichia coli
O157:H7 grown (18 h) in Tryptic Soy Broth (TSB) and TSB supplemented with 1.25%
glucose (TSBG), i.e. unadapted and acid-adapted cells, respectively, exhibited
changes in tolerance to reduced pH when plated on Tryptic Soy Agar (TSA)
acidified (pH 3.9, 4.2, 4.5, 4.8, 5.1 and 5.4) with acetic, citric or malic
acids. All test strains grew well on TSA acidified with acetic acid at pH >
or = 5.4 or malic acid at pH > or = 4.5; two strains grew on TSA acidified
with citric acid at pH > or = 4.5, while the third strain grew at pH > or
= 4.8. Acid-adapted and control (unadapted) cells differed little in their
ability to form visible colonies on TSA containing the same acid at the same pH.
However, on plates not showing visible colonies, acid-adapted cells retained
higher viability than unadapted cells when plated on acidified TSA. Growth of
acid-adapted and control cells of E. coli O157:H7 inoculated into TSB containing
acetic acid (pH 5.4 and 5.7) and citric or malic acids (pH 4.2 and 4.5) was also
studied. There was essentially no difference in growth characteristics of the
two types of cells in TSB acidified at the same pH with a given acid. Tolerance
of acid-adapted and control cells on subsequent exposure to low pH is influenced
by the type of acidulant. The order of sensitivity at a given pH is acetic >
citric > malic acid. When performing acid challenge studies to determine
survival and growth characteristics of E. coli O157:H7 in foods, consideration
should be given to the type of acid to which cells have been exposed previously,
the procedure used to achieve acidic environments and possible differences in
response among strains. The use of strains less affected by pH than type of
acidulant or vice versa could result in an underestimation of the potential for
survival and growth of E. coli O157:H7 in acid foods.
- Language of Publication
- English
- Unique Identifier
- 99163105
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- MeSH Heading (Major)
- Acids, Acyclic|*PD; Adaptation, Physiological|*DE; Escherichia coli
O157|*GD/IP
- MeSH Heading
- Animal; Cattle; Culture Media; Feces|MI; Food Microbiology; Human;
Hydrogen-Ion Concentration; Meat Products|MI
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 1364-5072
- Country of Publication
- ENGLAND
Record 39 from database: MEDLINE
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- Title
- Effects of dentin surface treatments on the shear bond strength of
Vitrabond.
- Author
- Prati C; Montanari G; Biagini G; Fava F; Pashley DH
- Address
- School of Dentistry, Medical College of Georgia.
- Source
- Dent Mater, 1992 Jan, 8:1, 21-6
- Abstract
- The influences of nine dentin surface treatments were evaluated on the shear
bond strength of a new light-cured glass-ionomer cement (GIC) and on the SEM
morphology of the treated dentin surfaces. The following treatments were
performed: saline solution (control), NaOCl, acidic glycine, EDTA, malic acid,
malic acid plus glycine, polyacrylic acid, tannic acid, and neutral+acidic
oxalate solutions. Buccal dentin surfaces were polished with #320-grit abrasive
paper, treated with one of the chemicals, washed, and air-dried. Cylindrical GIC
samples were then applied to the dentin surface, stored in 100% humidity, and
tested after 24 h. SEM observations demonstrated no effect of saline or NaOCl
treatment on the smear layer but its complete removal with exposure of collagen
fibrils after malic or malic acid plus glycine treatment. Partial removal of the
smear layer occurred following glycine treatment and with tannic or polyacrylic
acids. Complete removal of the smear layer was seen after EDTA or pyruvic acid
treatment. Oxalate treatment produced a layer of crystals, which completely
covered the dentin surface. Shear bond strength of GIC was significantly
increased only by treatment with the oxalate solutions.
- Language of Publication
- English
- Unique Identifier
- 92394372
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- MeSH Heading (Major)
- Dental Bonding|*; Dentin|*/DE; Glass Ionomer Cements|*CH
- MeSH Heading
- Comparative Study; Materials Testing; Microscopy, Electron, Scanning;
Support, U.S. Gov't, Non-P.H.S.; Support, U.S. Gov't, P.H.S.; Surface
Properties; Surface-Active Agents|PD; Tensile Strength
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0109-5641
- Country of Publication
- DENMARK
Record 40 from database: MEDLINE
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- Title
- Terminal differentiation in the avian uropygial gland. Accumulation of fatty
acid synthase and malic enzyme in non-dividing cells.
- Author
- Jenik RA; Fisch JE; Goodridge AG
- Address
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio
44106.
- Source
- Cell Tissue Res, 1987 Nov, 250:2, 315-21
- Abstract
- The secretory tissue of the uropygial gland is of the holocrine type,
containing both dividing progenitor cells and lipid-filled differentiated cells.
In this study, we examined the relationship between cell division and
differentiation. The location of dividing cells was determined by
autoradiography of tissue sections from ducklings injected intra-abdominally
with 3H-thymidine. Only cells on the basal lamina of the tubules contained
labeled nuclei. Dividing cells were distributed uniformly over the length of the
tubules. Over the next five days, most of the labeled cells migrated to the
lumen of the tubules and disappeared. Cells containing the "lipogenic" enzymes,
fatty acid synthase and malic enzyme, were localized either immunocytochemically
using affinity-purified antibodies or cytochemically using a specific assay for
malic enzyme activity. Fatty acid synthase and malic enzyme were undetectable in
dividing basal cells but present at high levels in differentiating and
differentiated cells. Thus, basal cells lying along the basal lamina of the
tubules were replacing lipid-laden cells that were continually sloughed into the
lumens of the tubules. The signals for differentiation and enzyme accumulation
appear to be linked to one another and to cessation of cell division.
- Language of Publication
- English
- Unique Identifier
- 88109475
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- MeSH Heading (Major)
- Fatty Acid Synthetase Complex|*ME; Malate Dehydrogenase|*ME; Sebaceous
Glands|CY/EN/*GD
- MeSH Heading
- Aging; Animal; Cell Differentiation; Cell Division; Ducks; DNA Replication;
Grooming; Kinetics; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0302-766X
- Country of Publication
- GERMANY, WEST
Record 41 from database: MEDLINE
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- Title
- D-Malic enzyme of Pseudomonas fluorescens.
- Author
- Knichel W; Radler F
- Address
-
- Source
- Eur J Biochem, 1982 Apr, 123:3, 547-52
- Abstract
- By the enrichment culture technique 14 gram-negative bacteria and two yeast
strains were isolated that used D(+)-malic acid as sole carbon source. The
bacteria were identified as Pseudomonas putida, Pseudomonas fluorescens,
Pseudomonas aeruginosa and Klebsiella aerogenes. In cell-free extracts of P.
fluorescens and P. putida the presence of malate dehydrogenase, D-malic enzyme
(NAD-dependent) and L-malic enzyme (NADP-dependent) was demonstrated. D-Malic
enzyme from P. fluorescens was purified. Stabilization of the enzyme by 50 mM
ammonium sulphate an 1 mM EDTA was essential. Preparation of D-malic enzyme that
gave one band with disc gel electrophoresis showed a specific activity of 4-5
U/mg. D-Malic enzyme requires divalent cations. The Km values were for malate Km
= 0.3 mM and for NAD Km = 0.08 mM. The pH optimum for the reaction was found to
be in the range of pH 8.1 to pH 8.8. D-Malic enzyme is partially inhibited by
oxaloacetic acid, meso-tartaric acid, D-lactic acid and ATP. Determined by gel
filtration and gradient gel electrophoresis, the molecular weight was
approximately 175 000.
- Language of Publication
- English
- Unique Identifier
- 82186730
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- MeSH Heading (Major)
- Malate Dehydrogenase|*IP; Pseudomonas fluorescens|*EN
- MeSH Heading
- Cell-Free System; Electrophoresis, Polyacrylamide Gel; Kinetics; Klebsiella
pneumoniae|EN; Molecular Weight; Pseudomonas|EN
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-2956
- Country of Publication
- GERMANY, WEST
Record 42 from database: MEDLINE
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- Title
- Role of NADP+ (corrected)-linked malic enzymes as regulators of the pool
size of tricarboxylic acid-cycle intermediates in the perfused rat heart
[published erratum appears in Biochem J 1987 Aug 1:245(3):following 934]
- Author
- Sundqvist KE; Heikkilä J; Hassinen IE; Hiltunen JK
- Address
- Department of Medical Biochemistry, University of Oulu, Finland.
- Source
- Biochem J, 1987 May, 243:3, 853-7
- Abstract
- Cytosolic and mitochondrial concentrations of malate, 2-oxoglutarate,
isocitrate and pyruvate in the isolated perfused rat heart were measured by
non-aqueous tissue fractionation, taking the NADP-linked isocitrate
dehydrogenase as indicator reactions for the free [NADPH]/[NADP+] ratios. The
mass-action ratios of NADP-linked malic enzymes (EC 1.1.1.40) were found to be
on the side of pyruvate carboxylation by more than one order of magnitude in
both the cytosolic and the mitochondrial spaces in hearts perfused with glucose,
whereas during propionate perfusion this ratio approached the equilibrium
constant (Keq.) of malic enzyme. The results consequently indicate that the
NADP-linked malic enzymes cannot be responsible for the feed-out (cataplerotic)
reactions from the tricarboxylic acid cycle which occur during glucose
perfusion. Only when other anaplerotic fluxes into the cycle are high, as during
propionate oxidation, which results in accumulation of tricarboxylic acid-cycle
intermediates, is a steady state reached which allows efflux via the malic
enzyme.
- Language of Publication
- English
- Unique Identifier
- 88023948
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- MeSH Heading (Major)
- Citric Acid Cycle|*; Malate Dehydrogenase|*ME; Myocardium|*ME; NADP|*ME
- MeSH Heading
- Animal; Cell Compartmentation; Female; Oxidation-Reduction; Perfusion; Rats;
Rats, Inbred Strains; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0264-6021
- Country of Publication
- ENGLAND
Record 43 from database: MEDLINE
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- Title
- Chimeric structure of the NAD(P)+- and NADP+-dependent malic enzymes of
Rhizobium (Sinorhizobium) meliloti.
- Author
- Mitsch MJ; Voegele RT; Cowie A; Osteras M; Finan TM
- Address
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton,
Ontario L8S 4K1, Canada.
- Source
- J Biol Chem, 1998 Apr, 273:15, 9330-6
- Abstract
- Malic enzymes catalyze the oxidative decarboxylation of malate to pyruvate
in conjunction with the reduction of a nicotinamide cofactor. We determined the
DNA sequence and transcriptional start sites of the genes encoding the
diphosphopyridine nucleotide-dependent malic enzyme (DME, EC 1.1.1.39) and the
triphosphopyridine nucleotide-dependent malic enzyme (TME, EC 1.1.1. 40) of
Rhizobium (Sinorhizobium) meliloti. The predicted DME and TME proteins contain
770 and 764 amino acids, respectively, and are approximately 320 amino acids
larger than previously characterized prokaryotic malic enzymes. The increased
size of DME and TME resides in the C-terminal extensions which are similar in
sequence to phosphotransacetylase enzymes (EC 2.3.1.8). Modified DME and TME
proteins which lack this C-terminal region retain malic enzyme activity but are
unable to oligomerize into the native state. Data base searches have revealed
that similar chimeric malic enzymes were uniquely present in Gram-negative
bacteria. Thus DME and TME appear to be members of a new class of malic enzyme
characterized by the presence of a phosphotransacetylase-like domain at the C
terminus of the protein.
- Language of Publication
- English
- Unique Identifier
- 98204936
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- MeSH Heading (Major)
- Evolution, Molecular|*; Malate Dehydrogenase|*CH/*GE/ME; Rhizobium
meliloti|*EN/GE
- MeSH Heading
- Amino Acid Sequence; Bacteria|EN/GE; Chimeric Proteins|BI/CH/ME; Comparative
Study; Molecular Sequence Data; Phylogeny; Sequence Alignment; Sequence
Homology, Amino Acid; Software; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 44 from database: MEDLINE
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- Title
- Coding nucleotide sequence of rat liver malic enzyme mRNA.
- Author
- Magnuson MA; Morioka H; Tecce MF; Nikodem VM
- Address
-
- Source
- J Biol Chem, 1986 Jan, 261:3, 1183-6
- Abstract
- The nucleotide sequence of the mRNA for malic enzyme ((S)-malate NADP+
oxidoreductase (oxaloacetate-decarboxylating, EC 1.1.1.40) from rat liver was
determined from three overlapping cDNA clones. Together, these clones contain
2078 nucleotides complementary to rat liver malic enzyme mRNA. The single open
reading frame of 1761 nucleotides codes for a 585-amino acid polypeptide with a
calculated molecular mass of about 65,460 daltons. The cloned cDNAs contain the
complete 3'-noncoding region of 301 nucleotides for the major mRNA species of
rat liver and 16 nucleotides of the 5'-noncoding region. Amino acid sequences of
seven tryptic peptides (67 amino acids) from the purified protein are
distributed through the single open reading frame and show excellent
correspondence with the translated nucleotide sequence. The putative
NADP-binding site for malic enzyme was identified by amino acid sequence
homology with the NADP-binding site of the enoyl reductase domain of fatty acid
synthetase.
- Language of Publication
- English
- Unique Identifier
- 86111756
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- MeSH Heading (Major)
- Malate Dehydrogenase|*GE/ME; RNA, Messenger|*AN
- MeSH Heading
- Amino Acid Sequence; Animal; Base Sequence; Binding Sites; Cloning,
Molecular; DNA|AN; Liver|EN; Molecular Weight; NADP|ME; Peptide Fragments|AN;
Rats; Trypsin|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 45 from database: MEDLINE
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- Title
- Effects of grinding and humidification on the transformation of conglomerate
to racemic compound in optically active drugs.
- Author
- Piyarom S; Yonemochi E; Oguchi T; Yamamoto K
- Address
- Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences,
Chiba University, Japan.
- Source
- J Pharm Pharmacol, 1997 Apr, 49:4, 384-9
- Abstract
- The effects of grinding and humidification on the transformation of
conglomerate to racemic compound have been investigated by X-ray powder
diffraction (XPD), differential scanning calorimetry (DSC) and infrared (IR)
spectroscopy for leucine, norleucine, valine, serine, tartaric acid and malic
acid. Racemic physical mixtures were prepared by physical mixing of equimolar
quantities of D and I. crystals using a mortar and pestle. Ground mixtures were
obtained by grinding the physical mixtures with a vibrational mill.
Humidification was performed by storing the physical mixtures and the ground
mixtures in a desiccator containing saturated aqueous salt solutions at 40
degrees C. When physical mixtures of malic acid, tartaric acid and serine were
ground, the XPD peaks of the racemic compounds were observed. The XPD patterns
of humidified physical mixtures of these compounds also showed the formation of
the racemic compounds. This indicated that grinding or humidification of malic
acid, tartaric acid and serine induced the transformation of conglomerate to
racemic compound crystals. When, on the other hand, the physical mixtures of
valine, leucine and norleucine were ground, peaks of racemic compounds were not
detected in the XPD pattern. After humidification of the ground mixtures of
valine, leucine and norleucine, however, the XPD peaks of racemic compounds were
observed. DSC and IR studies revealed consistent results. We concluded that
grinding or humidification of malic acid, tartaric acid and serine could induce
the transformation of a conglomerate to racemic compound. In contrast,
humidifying after grinding was needed to bring about the transformation in
leucine, norleucine and valine.
- Language of Publication
- English
- Unique Identifier
- 97376425
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- MeSH Heading (Major)
- Leucine|*CH; Malates|*CH; Norleucine|*CH; Serine|*CH; Tartrates|*CH;
Valine|*CH
- MeSH Heading
- Calorimetry, Differential Scanning; Humidity; Optical Rotation; Reference
Standards; Spectrophotometry, Infrared; Stereoisomerism; Support, Non-U.S.
Gov't; Temperature; X-Ray Diffraction
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-3573
- Country of Publication
- ENGLAND
Record 46 from database: MEDLINE
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- Title
- The distribution of six enzymes of oxidative metabolism along the rat
nephron.
- Author
- Burch HB; Bross TE; Brooks CA; Cole BR; Lowry OH
- Address
-
- Source
- J Histochem Cytochem, 1984 Jul, 32:7, 731-6
- Abstract
- Using quantitative methods, citrate synthase (CS), fumarase,
beta-hydroxyacyl-coenzyme A (CoA) dehydrogenase (beta OAC), 3-keto-acid CoA
transferase (KCT), malic dehydrogenase (MDH), and malic enzyme were measured in
seven defined parts of the nephron and in thin limb and papilla areas dissected
from freeze-dried microtome sections of rat kidney. The results not only show a
wide range of activity along the nephron for each of the enzymes, but that the
proportions between the enzymes vary markedly among the different parts of the
nephron. This suggests the existence of major regional differences in the
capacity to oxidize specific metabolites. The ratio between two citrate cycle
enzymes, fumarase and CS, was 4- or 5-fold higher in proximal segments than in
the glomerulus or thin limb areas. The ratio between beta OAC (an enzyme of
fatty acid oxidation) and CS was 3- to 5-fold higher in the middle proximal
segments than in glomeruli or thin limb and papilla areas. The key enzyme for
ketone body metabolism, KCT, was essentially confined to the thick tubule
segments. Malic enzyme, in contrast to the other five enzymes, was highest in
the proximal straight segments. New methods, sufficiently sensitive for this
histochemical study, are described for malic enzyme and 3-keto-acid CoA
transferase.
- Language of Publication
- English
- Unique Identifier
- 84241023
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- MeSH Heading (Major)
- Citric Acid Cycle|*; Nephrons|*EN/UL
- MeSH Heading
- Animal; Citrate (si)-Synthase|ME; Fumarate Hydratase|ME; Kidney
Cortex|EN/UL; Malate Dehydrogenase|ME; Male; Mitochondria|EN;
Oxidation-Reduction; Rats; Rats, Inbred Strains; Sulfurtransferases|ME; Support,
Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.; 3-Hydroxyacyl CoA Dehydrogenases|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-1554
- Country of Publication
- UNITED STATES
Record 47 from database: MEDLINE
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- Title
- Mode of action of the yeast Saccharomyces cerevisiae as a feed additive for
ruminants.
- Author
- Newbold CJ; Wallace RJ; McIntosh FM
- Address
- Rowett Research Institute, Bucksburn, Aberdeen.
- Source
- Br J Nutr, 1996 Aug, 76:2, 249-61
- Abstract
- Two suggested modes of action of yeast in stimulating rumen fermentation
were investigated. The first, that yeast respiratory activity protects anaerobic
rumen bacteria from damage by O2, was tested using different strains of yeast
that had previously been shown to have differing abilities to increase the
viable count of rumen bacteria. Saccharomyces cerevisiae NCYC 240, NCYC 1026,
and the commercial product Yea-Sacc, added to rumen fluid in vitro at 1.3 mg/ml,
increased the rate of O2 disappearance by between 46 and 89%. The same three
preparations also stimulated bacterial numbers in an in vitro fermenter
(Rusitec). S. cerevisiae NCYC 694 and NCYC 1088, which had no influence on the
viable count in Rusitec, also had no effect on O2 uptake. Respiration-deficient
(RD) mutants of S. cerevisiae NCYC 240 and NCYC 1026 were enriched by repeated
culturing in the presence of ethidium bromide. S. cerevisiae NCYC 240 and NCYC
1026 stimulated the total and cellulolytic bacterial populations in Rusitec,
while the corresponding RD mutants did not. Rigorous precautions to exclude air
from Rusitec resulted in S. cerevisiae NCYC 240 no longer stimulating total
bacterial numbers, although it still increased numbers of cellulolytic bacteria.
The second hypothesis, that yeast provides malic and other dicarboxylic acids
which stimulate the growth of some rumen bacteria, was examined by comparing the
effects of yeast and malic acid on rumen fermentation in sheep. Three mature
sheep were given 0.85 kg barley/d plus 0.55 kg chopped ryegrass hay/d either
unsupplemented, or supplemented with 4 g S. cerevisiae NCYC 240/d or 100 mg
L-malic acid/d either mixed with the diet or in aqueous solution infused
continuously into the rumen. Yeast increased the total viable count of bacteria
(P < 0.05) whereas malic acid did not, and no other effect of the treatments
reached statistical significance. It was concluded, therefore, that the
stimulation of rumen bacteria by S. cerevisiae is at least partly dependent on
its respiratory activity, and is not mediated by malic acid.
- Language of Publication
- English
- Unique Identifier
- 96408914
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- MeSH Heading (Major)
- Bacteria|*ME; Fermentation|*/DE; Food Additives|*; Rumen|*ME/MI;
Saccharomyces cerevisiae|*; Sheep|*ME
- MeSH Heading
- Animal; Malates|PD; Oxygen|ME; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0007-1145
- Country of Publication
- ENGLAND
Record 48 from database: MEDLINE
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- Title
- Cloning and analysis of the C4 photosynthetic NAD-dependent malic enzyme of
amaranth mitochondria.
- Author
- Long JJ; Wang JL; Berry JO
- Address
- Department of Biological Sciences, State University of New York at Buffalo
14260.
- Source
- J Biol Chem, 1994 Jan, 269:4, 2827-33
- Abstract
- In some C4 plant species, a mitochondrial NAD-dependent malic enzyme (EC
1.1.1.39) (NAD-ME) catalyzes the decarboxylation of 4 carbon malate in the
bundle sheath cells, releasing CO2 for the Calvin cycle of photosynthesis. In
amaranth, a dicotyledonous NAD-ME-type C4 plant, the photosynthetic NAD-ME
purified as two subunits of 65 and 60 kDa, designated alpha and beta,
respectively. Antiserum raised against the alpha subunit reacted only with the
65-kDa protein in immunoblot analysis. Immunogold electron microscopy using the
alpha subunit antiserum demonstrated that this protein was localized
specifically to the mitochondrial matrix of bundle sheath cells. The complete
nucleotide sequence of a 2300-base pair alpha subunit cDNA clone showed that
this gene encodes a protein that contains all of the motifs required for a
complete and functional malic enzyme. The alpha subunit has significant
similarity along its entire length to other known NAD- and NADP-dependent malic
enzymes from plants, animals, and bacteria. The findings presented here provide
new insights about the C4 photosynthetic NAD-ME and its evolutionary
relationship to other forms of malic enzyme present in eukaryotic and
prokaryotic organisms.
- Language of Publication
- English
- Unique Identifier
- 94132054
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- MeSH Heading (Major)
- Malate Dehydrogenase|AN/*BI/IP; Photosynthesis|*; Plants|*EN
- MeSH Heading
- Amino Acid Sequence; Animal; Bacillus stearothermophilus|EN; Base Sequence;
Blotting, Western; Chloroplasts|EN; Cloning, Molecular; Comparative Study;
Conserved Sequence; Corn|EN; Human; Macromolecular Systems; Mice; Microscopy,
Immunoelectron; Mitochondria|EN; Molecular Sequence Data; Sequence Homology,
Amino Acid; Support, U.S. Gov't, Non-P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 49 from database: MEDLINE
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- Title
- [U-13C]glutamate metabolism in rat brain mitochondria reveals malic enzyme
activity.
- Author
- Bakken IJ; Sonnewald U; Clark JB; Bates TE
- Address
- Institute of Physics, Norwegian University of Science and Technology (NTNU),
Trondheim, Norway.
- Source
- Neuroreport, 1997 May, 8:7, 1567-70
- Abstract
- 13C nuclear magnetic resonance spectroscopy was used to study the activity
of malic enzyme in isolated brain mitochondria from rat in the presence of
unlabelled malate and [U-13C]glutamate. ADP, inorganic phosphate, malate and
[U-13C]glutamate were added to a suspension of oxygenated mitochondria. Typical
tricarboxylic acid (TCA) cycle constituents (malate, 2-oxoglutarate and
succinate) were labelled from [U-13C]glutamate and detected in the superfusion
medium. The labelling patterns in the different atom positions of glutamate
revealed entry of both unlabelled and labelled acetyl-CoA into the TCA cycle.
Unlabelled acetyl-CoA was derived via pyruvate from exogenously applied malate
by the action of mitochondrial malic enzyme, while labelled acetyl-CoA was
derived from TCA cycle intermediates, most likely by the action of mitochondrial
malic enzyme on malate produced from [U-13C]glutamate. The results demonstrate
malic enzyme activity and pyruvate recycling in isolated rat brain mitochondria.
- Language of Publication
- English
- Unique Identifier
- 97333766
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full text for this document
- MeSH Heading (Major)
- Brain|EN/*ME; Glutamic Acid|*ME; Malate Dehydrogenase|*ME; Malates|*ME;
Mitochondria|EN/*ME
- MeSH Heading
- Animal; Carbon Isotopes; In Vitro; Male; Nuclear Magnetic Resonance;
Pyruvates|ME; Rats; Rats, Wistar; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0959-4965
- Country of Publication
- ENGLAND
Record 50 from database: MEDLINE
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full text for this document
- Title
- The NADPH consumption regulates the NADPH-producing pathways (pentose
phosphate cycle and malic enzyme) in rat adipocytes.
- Author
- Fabregat I; Revilla E; Machado A
- Address
-
- Source
- Mol Cell Biochem, 1987 Mar, 74:1, 77-81
- Abstract
- The changes in the activity of the pentose phosphate cycle and the malic
enzyme produced by the activation or inhibition of different NADPH-consuming
pathways have been studied. The inhibition of the fatty acid synthesis by
kynurenate produced a decrease in the flux through the pentose phosphate cycle
and a diminution in the malic enzyme pathway. The incubation of the adipocytes
in the presence of ter-butyl-hydroperoxide, a compound which is metabolized via
a NADPH-consuming pathway, produced a big increase in the pentose phosphate
cycle and the malic enzyme activities. The regulation of these NADPH-producing
pathways by the NADPH/NADP ratio is discussed.
- Language of Publication
- English
- Unique Identifier
- 87228747
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full text for this document
- MeSH Heading (Major)
- Adipose Tissue|*ME; Malate Dehydrogenase|*ME; NADP|*ME; Pentosephosphate
Pathway|*/DE
- MeSH Heading
- Animal; Carmustine|PD; Female; Kinetics; Kynurenic Acid|PD;
Oxidation-Reduction; Peroxides|PD; Rats; Rats, Inbred Strains; Support, Non-U.S.
Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0300-8177
- Country of Publication
- NETHERLANDS
Record 51 from database: MEDLINE
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- Title
- Effects of growth hormone on lipogenic enzyme activities in cultured rat
hepatocytes.
- Author
- Schaffer WT
- Address
-
- Source
- Am J Physiol, 1985 Jun, 248:6 Pt 1, E719-25
- Abstract
- The presence of cloned methionyl human growth hormone at 1 microgram/ml
medium for the final 5 days of a 6-day culture period decreased the activity of
malic enzyme (EC 1.1.1.40) 45% from 202 to 112, fatty acid synthetase 52% from
26 to 12, and ATP citrate lyase (EC 4.1.3.8) 20% from 192 to 154 nmol
NADPH.min-1.mg-1 supernatant protein in rat hepatocytes maintained in serum-free
primary culture. Also, the activity of mitochondrial glycerol-3-phosphate
dehydrogenase (EC 1.1.99.5) decreased 52% from 20 to 9 nmol.min-1.mg-1
mitochondrial protein. In the same cells, no changes were observed in the
activity of 6-phosphogluconate dehydrogenase (EC 1.1.1.44) and lactate
dehydrogenase (EC 1.1.1.27). Glucose-6-phosphate dehydrogenase (EC 1.1.1.49) was
increased 2.4-fold from 70 to 183 nmol.min-1.mg-1 protein, indicating the
activity of this enzyme was paradoxically increased, whereas other enzymes
involved in lipogenesis were decreased. Half-maximal decrease of malic enzyme
activity and increase of glucose-6-phosphate dehydrogenase activity occurred at
10 and 3 ng methionyl human growth hormone per milliliter medium, respectively.
These values are within the range of normal circulating growth hormone
concentrations in the rat. The effects on malic enzyme and glucose-6-phosphate
dehydrogenase appeared after 3-day exposure to growth hormone. These findings
are consistent with the hypothesis that growth hormone antagonizes the action of
agents that stimulate the activity of malic enzyme while concomitantly
increasing the extractable activity of glucose-6-phosphate dehydrogenase.
- Language of Publication
- English
- Unique Identifier
- 85222657
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full text for this document
- MeSH Heading (Major)
- Hormones, Synthetic|*PD; Liver|CY/DE/*EN; Somatotropin|*AA/PD
- MeSH Heading
- Animal; ATP Citrate (pro-S)-Lyase|ME; Cells, Cultured; Fatty Acid Synthetase
Complex|ME; Glucosephosphate Dehydrogenase|ME; Lactate Dehydrogenase|ME; Malate
Dehydrogenase|ME; Male; Phosphogluconate Dehydrogenase|ME; Rats; Rats, Inbred
Strains; Time Factors
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0002-9513
- Country of Publication
- UNITED STATES
Record 52 from database: MEDLINE
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full text for this document
- Title
- Nutritional regulation of lipogenic enzyme gene expression in rat epididymal
adipose tissue.
- Author
- Iritani N; Fukuda H; Tada K
- Address
- Tezukayama Gakuin College, Osaka.
- Source
- J Biochem (Tokyo), 1996 Aug, 120:2, 242-8
- Abstract
- The time courses of gene expression, and the nutritional regulation of gene
expression of lipogenic enzymes (acetyl-CoA carboxylase, fatty acid synthase,
ATP citrate-lyase, malic enzyme, and glucose-6-phosphate dehydrogenase) in
epididymal adipose tissue after refeeding food-deprived rats have been
investigated and compared with those in liver (previously reported). The mRNA
concentrations of lipogenic enzymes reached maximum levels at 24 h after the
refeeding in adipose tissue and at 8-16 h in liver, while the enzyme induction
reached maximum at 48-72 h in both tissues. Moreover, the mRNAs were more
strongly induced in adipose tissue than in liver, whereas the enzyme induction
(except malic enzyme) was lower. In adipose tissue of rats fed a carbohydrate
diet without protein, the mRNA concentrations of acetyl-CoA carboxylase,
ATP-citrate lyase, malic enzyme, and fatty acid synthase reached comparable
levels to those of the carbohydrate/protein diet group. The protein feeding
increased the enzyme induction in adipose tissue. As regards reduction of gene
expression, lipogenic enzyme mRNA concentrations were not so markedly reduced by
starvation or polyunsaturated fatty acids in adipose tissue as in liver. The
differences in regulation of lipogenic enzyme gene expression and induction
between adipose tissue and liver can be ascribed to tissue specificity.
- Language of Publication
- English
- Unique Identifier
- 97044735
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full text for this document
- MeSH Heading (Major)
- Adipose Tissue|DE/EN/*ME; Lipids|*BI
- MeSH Heading
- Acetyl-CoA Carboxylase|BI/GE; Animal; Animal Nutrition; ATP Citrate
(pro-S)-Lyase|BI/GE; Diabetes Mellitus, Experimental|EN/GE/ME; Enzyme Induction;
Epididymis|DE/EN/ME; Fatty Acid Synthetase Complex|BI/GE; Food Deprivation; Gene
Expression Regulation, Enzymologic|DE; Glucosephosphate Dehydrogenase|BI/GE;
Insulin|PD; Liver|DE/EN/ME; Malate Dehydrogenase|BI/GE; Male; Organ Specificity;
Rats; Rats, Wistar; RNA, Messenger|GE/ME; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-924X
- Country of Publication
- JAPAN
Record 53 from database: MEDLINE
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full text for this document
- Title
- Membrane enzymes associated with the dissimilation of some citric acid cycle
substrates and production of extracellular oxidation products in chemostat
cultures of Pseudomonas fluorescens.
- Author
- Lee WS; Cooper JK; Lynch WH
- Address
-
- Source
- Can J Microbiol, 1984 Mar, 30:3, 396-405
- Abstract
- Enzyme activities forming extracellular products from succinate, fumarate,
and malate were examined using washed cell suspensions of Pseudomonas
fluorescens from chemostat cultures. Membrane-associated enzyme activities
(glucose, gluconate, and malate dehydrogenases), producing large accumulations
of extracellular oxidation products in carbon-excess environments, have
previously been found in P. fluorescens. Investigations carried out here have
demonstrated the presence in this microorganism of a malic enzyme activity which
produces extracellular pyruvate from malate in carbon-excess environments.
Although the three membrane dehydrogenase enzymes decrease significantly in
carbon-limited chemostat cultures, malic enzyme activity was found to increase
fourfold under these conditions. The regulation of malate dehydrogenase and
malic enzyme by malate or succinate was similar. Malate dehydrogenase increased
and malic enzyme decreased in carbon-excess cultures. The opposite effect was
observed in carbon-limited cultures. When pyruvate or glucose was used as the
carbon source, malate dehydrogenase was regulated similarly by the available
carbon concentration, but malic enzyme activity producing extracellular pyruvate
was not detected. While large accumulations of extracellular oxalacetate and
pyruvate were produced in malate-excess cultures, no extracellular oxidation
products were detected in succinate-excess cultures. This may be explained by
the lack of detectable activity for the conversion of added external succinate
to extracellular fumarate and malate in cells from carbon-excess cultures. In
cells from carbon-limited (malate or succinate) cultures, very active enzymes
for the conversion of succinate to extracellular fumarate and malate were
detected. Washed cell suspensions from these carbon-limited cultures rapidly
oxidized added succinate to extracellular pyruvate through the sequential action
of succinate dehydrogenase, fumarase, and malic enzyme. Succinate dehydrogenase
and fumarase activities producing extracellular products were not detected in
cells from chemostat cultures using pyruvate or glucose as the carbon source.
Uptake activities for succinate, malate, and pyruvate also were found to
increase in carbon-limited (malate or succinate) and decrease in carbon-excess
cultures. The role of the membrane-associated enzymes forming different pathways
for carbon dissimilation in both carbon-limited and carbon-excess environments
is discussed.
- Language of Publication
- English
- Unique Identifier
- 84205142
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full text for this document
- MeSH Heading (Major)
- Citric Acid Cycle|*; Pseudomonas fluorescens|*EN
- MeSH Heading
- Ammonia|ME; Carbohydrate Dehydrogenases|ME; Cell Membrane|EN; Fumarate
Hydratase|ME; Fumarates|ME; Glucose|ME; Glucose Dehydrogenases|ME; Malate
Dehydrogenase|ME; Malates|ME; Oxaloacetates|ME; Oxidation-Reduction;
Pseudomonas|ME; Pyruvates|BI; Succinate Dehydrogenase|ME; Succinates|ME;
Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0008-4166
- Country of Publication
- CANADA
Record 54 from database: MEDLINE
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full text for this document
- Title
- Comparative study of lipogenic enzymes in several vertebrates.
- Author
- Iritani N; Ikeda Y; Fukuda H; Katsurada A
- Address
-
- Source
- Lipids, 1984 Nov, 19:11, 828-35
- Abstract
- The liver lipogenic enzymes are compared among rats, chickens, frogs and
fish. Although the apparent Km values of glucose-6-phosphate dehydrogenase for
glucose-6-phosphate are not much different among all the species, those of malic
enzyme for malate are much higher in chickens and fish than in rats and frogs.
Glucose-6-phosphate dehydrogenase showed very high activities compared with
malic enzyme in fish liver, and malic enzyme showed high activities in chicken
liver. Although the apparent Km values of acetyl-CoA carboxylase and fatty acid
synthetase for substrates are in the same range among all the animals, the
activity of acetyl-CoA carboxylase seems to be extremely low in fish and frog
livers, and that of fatty acid synthetase is low in frog livers only. In
addition, the apparent Km values of alpha-glycerophosphate acyltransferase of
fish liver are very high, and the enzyme activity appears to be extremely low
compared to the others. Therefore, the enzymes at the first steps of both fatty
acid and glycerolipid syntheses of poikilothermos animals appear to be very low.
On the other hand, the Ouchterlony double-diffusion patterns showed that the
lipogenic enzymes of chickens, frogs and fish are immunologically different from
those of rats, with the exception of acetyl-CoA carboxylase in chickens.
Therefore, it is suggested that the fatty acid and glycerolipid forming systems
of poikilothermos animals are quite different from those of homoiothermos and
the lipogenesis is very low in poikilothermos.
- Language of Publication
- English
- Unique Identifier
- 85110305
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full text for this document
- MeSH Heading (Major)
- Lipids|*BI
- MeSH Heading
- Acetic Acids|ME; Acetyl-CoA Carboxylase|ME; Acyltransferases|ME; Animal;
Bufonidae; Chickens; Comparative Study; Diet; Fatty Acid Synthetase Complex|ME;
Fishes; Glucosephosphate Dehydrogenase|ME; Glycerol-3-Phosphate
O-Acyltransferase|ME; Immunodiffusion; Kinetics; Liver|EN; Malate
Dehydrogenase|ME; Male; Rats; Rats, Inbred Strains
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0024-4201
- Country of Publication
- UNITED STATES
Record 55 from database: MEDLINE
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- Title
- Hexanoate and octanoate inhibit transcription of the malic enzyme and fatty
acid synthase genes in chick embryo hepatocytes in culture.
- Author
- Roncero C; Goodridge AG
- Address
- Department of Biochemistry, University of Iowa, Iowa City 52242.
- Source
- J Biol Chem, 1992 Jul, 267:21, 14918-27
- Abstract
- Hexanoate and octanoate inhibit the triiodothyronine (T3)-induced increases
in the activities of malic enzyme and fatty acid synthase in chick embryo
hepatocytes in culture. Butanoate was less effective as an inhibitor, and
palmitate, stearate, and oleate had no effect or small stimulatory effects.
Hexanoate and octanoate inhibited the lipogenic enzyme activities at a
transcriptional step, and did so within 30 min of addition. Incubation for 2 h
in the absence of fatty acid reversed the inhibition of transcription caused by
hexanoate. The inhibitory effect of hexanoate was selective because DNA content
and transcription of the glyceraldehyde-3-phosphate dehydrogenase and beta-actin
genes were not inhibited. Hexanoate-mediated inhibition of transcription rates
of the lipogenic genes was not correlated with an inhibition of binding of T3 to
its nuclear receptor. 2-Bromooctanoate and carnitine stimulated the T3-induced
accumulation of the mRNAs for malic enzyme and fatty acid synthase. The presence
of hexanoate stimulated by 2- to 3-fold the increase caused by carnitine,
suggesting that hexanoate and carnitine may regulate lipogenic gene expression
by a common pathway. Hexanedioate, acetoacetate, beta-hydroxybutyrate, branched
chain fatty acids, and branched chain keto acids had little or no effect on
abundance of the lipogenic mRNAs. We suggest that the active inhibitor is a
metabolite derived from hexanoate or octanoate, possibly an intermediate derived
from an acyl-CoA derivative.
- Language of Publication
- English
- Unique Identifier
- 92340537
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full text for this document
- MeSH Heading (Major)
- Fatty Acid Synthetase Complex|*GE; Hexanoic Acids|*PD; Liver|CY/EM/*EN;
Malate Dehydrogenase|*GE; Octanoic Acids|*PD; Transcription, Genetic|*DE
- MeSH Heading
- Actins|GE; Animal; Blotting, Northern; Carnitine|PD; Cells, Cultured; Chick
Embryo; Drug Interactions; Glucagon|PD; Glyceraldehyde-3-Phosphate
Dehydrogenases|GE; RNA, Messenger|ME; Support, Non-U.S. Gov't; Support, U.S.
Gov't, P.H.S.; Triiodothyronine|PD
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 56 from database: MEDLINE
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full text for this document
- Title
- Cloning and molecular characterization of two genes encoding adhesion
proteins involved in Trichomonas vaginalis cytoadherence.
- Author
- Alderete JF; OBrien JL; Arroyo R; Engbring JA; Musatovova O; Lopez O;
Lauriano C; Nguyen J
- Address
- Department of Microbiology, University of Texas Health Science Center, San
Antonio 78284-7758, USA.
- Source
- Mol Microbiol, 1995 Jul, 17:1, 69-83
- Abstract
- Cytoadherence to the vaginal epithelium is a critical step in infection by
the eukaryotic flagellate Trichomonas vaginalis. Four trichomonad surface
proteins (AP65, AP51, AP33 and AP23) mediate cytoadherence. The cDNA encoding
the AP65 adhesin was isolated from a phagemid cDNA expression library by
screening with antiserum and monoclonal antibody (mAb) raised against the
purified trichomonad AP65 protein. Two clones, F11.2 and F11.5, coded for
immuno-crossreactive recombinant proteins that possessed functional properties
equal to the T. vaginalis AP65 adhesin. Analysis of full-length sequences
corresponding to the F11.2 and F11.5 cDNAs revealed that both contained
1701-base open reading frames (ORFs) that encoded proteins of 63 281 daltons and
83 087 daltons, respectively. Comparison of the full-length sequences showed 87%
identity at the nucleotide level and 91% identity at the protein level.
Restriction-enzyme mapping and Southern analysis reaffirmed the distinctness of
the F11.2 and F11.5 cDNAs, indicating that two different AP65 genes (now called
ap65-1 and ap65-2) are present in the T. vaginalis genome in at least two copies
each. Northern analysis detected high levels of transcript of approximately 1.8
kb for both ap65-1 and ap65-2 genes in trichomonads grown only in high-iron
medium, confirming the transcriptional regulation of adhesin synthesis by iron.
Homology searches revealed significant similarity (38% amino acid identity and
54% nucleotide identity) to malic enzymes. However, purified malic enzyme and
mAb to AP65 crossreactive with malic enzyme neither inhibited cytoadherence of
T. vaginalis to host cells nor prevented binding of the trichomonad AP65 to HeLa
cells in a ligand assay.
- Language of Publication
- English
- Unique Identifier
- 96020663
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full text for this document
- MeSH Heading (Major)
- Genes, Structural, Protozoan|*GE; Iron|*PD; Protozoan Proteins|CH/*GE/ME;
Trichomonas vaginalis|*GE
- MeSH Heading
- Amino Acid Sequence; Animal; Base Sequence; Cell Adhesion|GE; Cloning,
Molecular; DNA, Complementary|GE; Hela Cells|ME; Human; Molecular Sequence Data;
Multigene Family|GE; Promoter Regions (Genetics)|GE; Recombinant Fusion
Proteins|BI/ME; Restriction Mapping; RNA, Messenger|BI; RNA, Protozoan|BI;
Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Support, U.S.
Gov't, P.H.S.; Transcription, Genetic|DE
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0950-382X
- Country of Publication
- ENGLAND
Record 57 from database: MEDLINE
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full text for this document
- Title
- Characterization of the vacuolar ATPase activity of the
crassulacean-acid-metabolism plant Kalanchoë daigremontiana. Receptor
modulating.
- Author
- Smith JA; Uribe EG; Ball E; Heuer S; Lüttge U
- Address
-
- Source
- Eur J Biochem, 1984 Jun, 141:2, 415-20
- Abstract
- Plants performing crassulacean acid metabolism show a large nocturnal
accumulation of malic acid in the vacuole of the photosynthetic cells. It has
been postulated that an H+-translocating ATPase energizes the transport of malic
acid across the tonoplast into the vacuole. In the present work we have
characterized the ATPase activity associated with vacuoles of the
crassulacean-acid-metabolism plant Kalanchoë daigremontiana and compare it with
other phosphohydrolases. Vacuoles were isolated by polybase-induced lysis of
mesophyll-cell protoplasts. The vacuoles had a high activity of unspecific acid
phosphatase (pH optimum 5.3). The acid phosphatase was strongly inhibited by
ammonium molybdate (with 50% inhibition at about 0.5 mmol m-3), but was not
completely inhibited even at much higher ammonium-molybdate concentrations. In
contrast, the vacuolar ATPase activity, assayed in the presence of 100 mmol m-3
ammonium molybdate, had a pH optimum of 8.0. ATP was the preferred substrate,
but GTP, ITP and ADP were hydrolyzed at appreciable rates. The mean ATPase
activity at pH 8.0 was 14.5 nmol h-1 (10(3) vacuoles)-1, an average 13% of which
was attributable to residual acid-phosphatase activity.
Inorganic-pyrophosphatase activity could not be demonstrated unambiguously. The
vacuolar ATPase activity was Mg2+-dependent, had an apparent Km for MgATP2- of
0.31 mol m-3, and was 32% stimulated by 50 mol m-3 KCl. Of the inhibitors
tested, oligomycin slightly inhibited the vacuolar ATPase activity and
diethylstilbestrol and NO-3 were both markedly inhibitory.
Dicyclohexylcarbodiimide and tributyltin were also strongly inhibitory.
Tributyltin caused a 50% inhibition at about 0.3 mmol m-3. This is taken as
evidence that the vacuolar ATPase might function as an H+-translocating ATPase.
It is shown that the measured activity of the vacuolar ATPase would be of the
right order to account for the observed rates of nocturnal malic-acid
accumulation in K. daigremontiana.
- Language of Publication
- English
- Unique Identifier
- 84236176
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full text for this document
- MeSH Heading (Major)
- Adenosinetriphosphatase|AI/*ME; Chloroplasts|*EN; Organoids|*EN;
Photosynthesis|*; Plants|*EN/UL; Vacuoles|*EN
- MeSH Heading
- Acid Phosphatase|ME; Catalysis; Hydrogen-Ion Concentration; Hydrolysis;
Malates|ME; Substrate Specificity; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-2956
- Country of Publication
- GERMANY, WEST
Record 58 from database: MEDLINE
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full text for this document
- Title
- Kinetics of induction by thyroid hormone of the two hepatic mRNAs coding for
cytosolic malic enzyme in the hypothyroid and euthyroid states. Evidence against
an obligatory role of S14 protein in malic enzyme gene expression.
- Author
- Strait KA; Kinlaw WB; Mariash CN; Oppenheimer JH
- Address
- Department of Medicine, University of Minnesota, Minneapolis 55455.
- Source
- J Biol Chem, 1989 Nov, 264:33, 19784-9
- Abstract
- In rat liver, triiodothyronine (T3) and dietary carbohydrate induce the
expression of the genes coding for malic enzyme (ME) (EC 1.1.1.40) and S14
protein. The mRNAs for both ME and S14 are elevated under circumstances
associated with augmented lipogenesis. Since the lag time in the induction of
mRNA coding for S14 is short (20 min) and the lag time in the induction of the
mRNA for ME is relatively long (2-6 h), the possibility arose that the induction
of the ME gene by T3 was mediated by S14 protein. To test this hypothesis we
examined the temporal relationship between the accumulation of the hepatic S14
protein and the mRNAs coding for ME. In confirmation of previous reports, we
found that two mRNAs coded for ME, one 27 S and the other 21 S in size. The
level of enzyme activity generated appeared to be determined by both mRNA
species. Sequencing of the 27 S fragment established that this mRNA is generated
as a consequence of the use of an alternate polyadenylation site downstream to
that used in the 21 S mRNA. Unanticipated from the earlier descriptions was the
finding of a markedly asynchronous response of these mRNAs to T3 in hypothyroid
animals. The lag time following T3 administration was 90 min for the 27 S and
fully 8-12 h for the smaller 21 S sequence. Despite the rapid rise of mRNA S14,
the S14 protein could not be detected for approximately 12 h after T3
administration. This ruled out the possibility that S14 is an obligate mediator
in the induction of the ME gene. A contrasting pattern was observed in the
euthyroid state where both ME mRNAs had indistinguishable lag times of 2-3 h,
and the S14 protein rose within the same time frame. The delayed response of the
21 S mRNA for malic enzyme in hypothyroid animals thus appears to be due to a
reversible defect in the transcription of the ME gene.
- Language of Publication
- English
- Unique Identifier
- 90062081
Order
full text for this document
- MeSH Heading (Major)
- Gene Expression Regulation, Enzymologic|*/DE; Genes, Structural|*/DE;
Hypothyroidism|*EN; Liver|DE/*EN; Malate Dehydrogenase|BI/*GE; RNA,
Messenger|BI/DE/*GE; Thyroid Gland|*PH; Transcription, Genetic|*/DE;
Triiodothyronine|*PD
- MeSH Heading
- Animal; Base Sequence; Comparative Study; Kinetics; Male; Molecular Sequence
Data; Nucleic Acid Hybridization; Rats; Rats, Inbred Strains; Reference Values;
Restriction Mapping; Sequence Homology, Nucleic Acid; Support, U.S. Gov't,
P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 59 from database: MEDLINE
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full text for this document
- Title
- Structural characterization of the rat malic enzyme gene.
- Author
- Morioka H; Magnuson MA; Mitsuhashi T; Song MK; Rall JE; Nikodem VM
- Address
- Clinical Endocrinology Branch, National Institute of Diabetes, Digestive,
and Kidney Diseases, Bethesda, MD 20892.
- Source
- Proc Natl Acad Sci U S A, 1989 Jul, 86:13, 4912-6
- Abstract
- We have identified and characterized lambda bacteriophage clones containing
genomic DNA encoding rat malic enzyme [(S)-malate:NADP+ oxidoreductase
(oxaloacetate-decarboxylating); EC 1.1.1.40]. The malic enzyme gene is
unexpectedly large, spanning at least 95 kilobases. It is divided into 14 exons
that range in size from 76 to 1513 base pairs. The sizes and boundaries of the
exons were determined by Southern blotting and DNA sequencing. The sequences at
the 5' and 3' ends of each intron conformed to the consensus sequence for
mammalian introns. S1 nuclease and primer-extension assays showed that
transcription of the malic enzyme gene initiates at multiple sites, the
strongest one at position -31 relative to the ATG. "TATA and CCAAT box"
homologies are not present in the proximal promoter region. Analysis of the 3'
end of the gene showed that the utilization of alternate polyadenylylation
signals in exon 14 results in two mRNAs with 3' untranslated regions of 345 and
1345 nucleotides, respectively.
- Language of Publication
- English
- Unique Identifier
- 89296914
Order
full text for this document
- MeSH Heading (Major)
- Genes, Structural|*; Malate Dehydrogenase|*GE
- MeSH Heading
- Amino Acid Sequence; Animal; Base Sequence; Cloning, Molecular; Exons;
Introns; Molecular Sequence Data; Nucleic Acid Conformation; Rats; Restriction
Mapping; RNA, Messenger|GE
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0027-8424
- Country of Publication
- UNITED STATES
Record 60 from database: MEDLINE
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- Title
- Primary structure of the hydrogenosomal malic enzyme of Trichomonas
vaginalis and its relationship to homologous enzymes.
- Author
- Hrdý I; Müller M
- Address
- Rockefeller University, New York, New York 10021, USA.
- Source
- J Eukaryot Microbiol, 1995 Sep, 42:5, 593-603
- Abstract
- The complete nucleotide sequence has been established for two genes (maeA
and maeB) coding for different subunits of the hydrogenosomal malic enzyme
[malate dehydrogenase (decarboxylating) EC 1.1.1.39] of Trichomonas vaginalis.
Two further genes (maeC and maeD) of this enzyme have been partially sequenced.
The complete open reading frames code for polypeptides of 567 amino acids in
length. These two open reading frames are similar with less than 12 percent
pairwise nucleotide differences and less than 9 percent pairwise amino acid
differences. The open reading frames of the two partially sequenced genes
correspond to the amino-terminal part of the polypeptides coded and are similar
to the corresponding parts of the completely sequenced ones. The deduced
translation products of the two complete genes differ in their calculated pI
values by 1.5 pH unit. The genes code for polypeptides which contain 12 or 11
amino-terminal amino-acyl residues not present in the proteins isolated from the
cell. Other hydrogenosomal enzymes also have similar amino-terminal extensions
which probably play a role in organellar targeting and translocation of the
newly synthesized polypeptides. A comparison of 19 related enzymes from bacteria
and eukaryotes with the maeA product revealed 34-45 percent amino acid identity.
Phylogenetic reconstruction based on nonconservative amino acid differences with
maximum parsimony (phylogenetic analysis using parsimony, PAUP) and distance
based (neighbor-joining, NJ) methods showed that the T. vaginalis enzyme is the
most divergent of all eukaryotic malic enzymes, indicating its long independent
evolutionary history.
- Language of Publication
- English
- Unique Identifier
- 96010590
Order
full text for this document
- MeSH Heading (Major)
- Malate Dehydrogenase|*GE; Phylogeny|*; Sequence Homology, Amino Acid|*;
Trichomonas vaginalis|*EN/GE
- MeSH Heading
- Amino Acid Sequence; Animal; Cloning, Molecular; Genes, Structural,
Protozoan|GE; Molecular Sequence Data; Sequence Alignment; Sequence Analysis;
Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; Support, U.S. Gov't,
P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 1066-5234
- Country of Publication
- UNITED STATES
Record 61 from database: MEDLINE
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- Title
- Survival of Escherichia coli O157:H7 in synthetic gastric fluid after cold
and acid habituation in apple juice or trypticase soy broth acidified with
hydrochloric acid or organic acids.
- Author
- Uljas HE; Ingham SC
- Address
- Department of Food Science, University of Wisconsin-Madison 53706, USA.
- Source
- J Food Prot, 1998 Aug, 61:8, 939-47
- Abstract
- Extreme acid tolerance of Escherichia coli O157:H7 has raised doubts about
the safety of acidic foods. This study examined whether prior storage in acidic
and/or cold conditions enhanced survival of E. coli O157:H7 in synthetic gastric
fluid (SGF). Three E. coli O157:H7 strains were stored in trypticase soy broth
(TSB; acidified with HCl, malic acid, citric acid, or lactic acid) or pH 3.5 and
6.5 (nonacidic control) apple juice at 4 and 21 degrees C for < or = 7 days
and then were incubated in pH 2.5 SGF at 37 degrees C for 4 h. Cells survived
better in apple juice than in TSB containing organic acids, suggesting that
juice constituents other than organic acids protect E. coli O157:H7.
Refrigeration combined with low pH best protected cells in apple juice and
acidified TSB, but, compared to the nonacidic control, only acidified TSB
enhanced subsequent survival in pH 2.5 SGF. Equal survival in SGF occurred after
storage in pH 3.5 or 6.5 apple juice at 4 degrees C, suggesting that low
temperature alone in apple juice enhanced acid tolerance. Two strains stored at
4 degrees C in TSB containing malic or citric acid subsequently survived better
in SGF than cells stored in nonacidified TSB but poorer than cells stored in the
presence of HCl. These differences reflect the higher pKa of these organic
acids. However, subsequent survival of these strains in SGF was poorer after
refrigerated storage in apple juice than in TSB containing citric or malic
acids. Cells stored in lactic acid were most likely to be completely eliminated
upon transfer to SGF. Differences in survival in storage media or SGF related to
strain, storage conditions, or acidifier were consistent and often statistically
significant (P < 0.05). Although the survival of E. coli O157:H7 in
refrigerated acidic beverages may not be affected by the type of acidifier used,
the subsequent survival in SGF of this pathogen may be critically dependent on
this factor.
- Language of Publication
- English
- Unique Identifier
- 98379373
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- MeSH Heading (Major)
- Beverages|*MI; Caseins|*PD; Escherichia coli|*PH; Protein Hydrolysates|*PD
- MeSH Heading
- Cold; Hydrochloric Acid|PD; Hydrogen-Ion Concentration; Rosales; Support,
Non-U.S. Gov't; Support, U.S. Gov't, Non-P.H.S.; Temperature
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0362-028X
- Country of Publication
- UNITED STATES
Record 62 from database: MEDLINE
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- Title
- The peroxisome proliferator activated receptor regulates malic enzyme gene
expression.
- Author
- Castelein H; Gulick T; Declercq PE; Mannaerts GP; Moore DD; Baes MI
- Address
- Laboratory of Clinical Chemistry, Faculty of Pharmaceutical Sciences,
Catholic University of Leuven, Belgium.
- Source
- J Biol Chem, 1994 Oct, 269:43, 26754-8
- Abstract
- A new regulatory element for peroxisome proliferator activated receptor
(PPAR)/retinoid X receptor (RXR) heterodimers was found in the promoter of the
malic enzyme gene. Similar to previously characterized peroxisome proliferator
response elements (PPREs), it consists of a direct repeat of sequences related
to the half-site consensus AGGTCA with an interspacing of 1 base pair. Specific
binding of PPAR/RXR heterodimers to this element was demonstrated. Furthermore,
this sequence conferred ciprofibrate responsiveness of a reporter through the
homologous malic enzyme or heterologous thymidine kinase promoters. This PPRE
presumably mediates the transcriptional effects of peroxisome proliferators on
malic enzyme expression. The presence of a PPRE in the promoter of this
lipogenic enzyme suggests a broader function for the PPAR in the regulation of
lipid metabolism.
- Language of Publication
- English
- Unique Identifier
- 95014534
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- MeSH Heading (Major)
- Gene Expression Regulation, Enzymologic|*; Malate Dehydrogenase|*GE;
Promoter Regions (Genetics)|*GE; Receptors, Cytoplasmic and Nuclear|*ME;
Transcription Factors|*ME
- MeSH Heading
- Animal; Antilipemic Agents|PD; Base Sequence; Clofibric Acid|AA/PD; DNA
Mutational Analysis; Human; Mice; Molecular Sequence Data; Sequence Deletion;
Support, Non-U.S. Gov't; Trans-Activation (Genetics)
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 63 from database: MEDLINE
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- Title
- Characterization of a bean (Phaseolus vulgaris L.) malic-enzyme gene.
- Author
- Walter MH; Grima Pettenati J; Feuillet C
- Address
- Institut fÂur Pflanzenphysiologie (260), UniversitÂat Hohenheim, Stuttgart,
Germany.
- Source
- Eur J Biochem, 1994 Sep, 224:3, 999-1009
- Abstract
- We have isolated a genomic clone encoding a plant NADP(+)-dependent malic
enzyme (NADP-ME). This clone, isolated from bean (Phaseolus vulgaris L.), covers
the entire gene (exons, introns) and 5'-flanking regions. DNA sequencing defines
20 exons spanning approximately 4.5 kb, which range over 48-235 bp in size. All
19 introns are fairly small (79-391). The first intron resides in the
5'-untranslated leader sequence. Introns 10, 11 and 16 are located at positions
identical to a rat malic-enzyme gene. In the promoter region, a TATA box
(TATATATA) is easily recognized 41 bp upstream of a single
transcription-initiation site. Two potential cis-acting elements with homology
to elements from plant genes, activated by UV light and fungal elicitors, were
identified at positions -153 and -312, respectively. Southern-blot analysis
suggests a single gene copy, but also other distantly related genes, in the bean
genome. The deduced NADP-ME protein of 589 amino acids exhibits features
consistent with a cytoplasmic location. We describe the organization of the
NADP-ME protein into functional domains located on separate exons. The evolution
of malic-enzyme genes coding for isoforms in different cellular compartments of
plants and animals is discussed.
- Language of Publication
- English
- Unique Identifier
- 95010093
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- MeSH Heading (Major)
- Legumes|*EN; Malate Dehydrogenase|*GE; Plant Proteins|*GE
- MeSH Heading
- Amino Acid Sequence; Base Sequence; Cloning, Molecular; DNA, Plant; Exons;
Genes, Plant; Introns; Molecular Sequence Data; Promoter Regions (Genetics);
Sequence Homology, Amino Acid; Support, Non-U.S. Gov't; Transcription, Genetic
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-2956
- Country of Publication
- GERMANY
Record 64 from database: MEDLINE
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- Title
- Isolation and characterization of Kluyveromyces marxianus mutants deficient
in malate transport.
- Author
- Queiros O; Casal M; Althoff S; Moradas Ferreira P; Leao C
- Address
- Departamento de Biologia, Universidade do Minho, Braga, Portugal.
- Source
- Yeast, 1998 Mar, 14:5, 401-7
- Abstract
- In malic acid-grown cells of the strains ATCC 10022 and KMS3 of
Kluyveromyces marxianus the transport of malic acid occurred by a malate-proton
symport, which accepted L-malic, D-malic, succinic and fumaric acids, but not
tartaric, malonic or maleic acids. The system was inducible and subjected to
glucose repression. Mutants of the strain KMS3, unable to grow in a medium with
malic acid, were isolated and checked for their capacity to utilize several
carbon sources and to transport dicarboxylic acids by the malate-proton symport.
Two distinct clones affected on malate transport were obtained. Both were able
to grow on a medium with glycerol or ethanol but not with DL-malic, succinic,
oxoglutaric and oxaloacetic acids as the sole carbon and energy sources.
However, while one of the mutants (Mal7) displayed activity levels for the
enzymes malate dehydrogenase, isocitrate lyase, and phosphoenolpyruvate
carboxykinase similar to those of the wild strain, in the other mutant type
(Mal6) the activities for the same enzymes were significantly reduced. Plasma
membranes from derepressed cells of the wild strain and of the mutants Mal6 and
Mal7 were isolated and the protein analysed by SDS-PAGE. The electrophoretic
patterns of these preparations differed in a polypeptide with an apparent
molecular mass of about 28 kDa, which was absent only in the mutant Mal7. The
results indicated that Mal7 can be affected in a gene that encodes a malate
carrier in K. marxianus.
- Language of Publication
- English
- Unique Identifier
- 98220304
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full text for this document
- MeSH Heading (Major)
- Kluyveromyces|EN/GD/*GE/IP; Malates|*ME; Mutation|*
- MeSH Heading
- Biological Transport; Dicarboxylic Acids|ME; Electrophoresis, Polyacrylamide
Gel; Genes, Fungal; Glucose|ME; Isocitrate Lyase|ME; Malate Dehydrogenase|ME;
Membrane Proteins|AN; Protons; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0749-503X
- Country of Publication
- ENGLAND
Record 65 from database: MEDLINE
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- Title
- The effect of glycolic acid on cultured human skin fibroblasts: cell
proliferative effect and increased collagen synthesis.
- Author
- Kim SJ; Won YH
- Address
- Department of Dermatology, Chonnam University Research Institute of Medical
Science, Chonnam National University Medical School, Kwangju, Korea.
- Source
- J Dermatol, 1998 Feb, 25:2, 85-9
- Abstract
- Glycolic acid peeling is known to improve photoaging processes such as
wrinkling and roughness, but this effect has not been clearly defined, even
though functional activation of fibroblasts has been suggested. The study was
aimed to determine the effects of glycolic acid and malic acid (AHA: alpha
hydroxy acid) on cultured dermal fibroblasts. Whether it directly increases cell
proliferation may be an important factor influencing the production of
extracellular matrix such as type I collagen. Cultured human skin fibroblasts
were treated for 24 hours with glycolic acid and malic acid at different
concentrations (10(-4), 10(-5), 10(-6) M), and cell proliferation was measured
by MTT assay. Then quantitative analysis of collagen synthesis was performed by
PICP (Procollagen Type I C-peptide) enzyme immunoassay and radioisotope
(3H-proline) labelled collagen assay. The results showed increased cell
proliferation and collagen production in response to glycolic acid in a dose
dependent manner. The range of cell proliferation and collagen production were
significantly higher with glycolic acid treatment than with malic acid or
control. It was suggested that the favorable effects of glycolic acid treatment
on aging skin were mediated by increased cell proliferation in addition to
functional activation of fibroblasts.
- Language of Publication
- English
- Unique Identifier
- 98224378
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full text for this document
- MeSH Heading (Major)
- Cell Division|*DE; Collagen|BI/*DE; Fibroblasts|*DE/ME; Glycolates|*PD;
Malates|*PD; Skin|CY/*DE/ME
- MeSH Heading
- Cells, Cultured; Comparative Study; Human; Immunoenzyme Techniques; Infant,
Newborn; Male; Reference Values; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0385-2407
- Country of Publication
- JAPAN
Record 66 from database: MEDLINE
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- Title
- Cloning and sequence analysis of the gene encoding Lactococcus lactis
malolactic enzyme: relationships with malic enzymes.
- Author
- Denayrolles M; Aigle M; Lonvaud Funel A
- Address
- Institut d'Oenologie, UniversitÆe de Bordeaux II, Talence, France.
- Source
- FEMS Microbiol Lett, 1994 Feb, 116:1, 79-86
- Abstract
- Malolactic enzyme is the key enzyme in the degradation of L-malic acid by
lactic acid bacteria. Using degenerated primers designed from the first 20
N-terminal amino acid sequence of lactococcal malolactic enzyme, a 60-bp DNA
fragment containing part of the mleS gene was amplified from Lactococcus lactis
in a polymerase chain reaction. This specific probe was used to isolate two
contiguous fragments covering the gene as a whole. The 1.9-kb region sequenced
contains an open reading frame of 1623 bp, coding a putative protein of 540
amino acids. The deduced amino acid sequence reveals that lactococcal putative
protein (Mlep) is highly homologous to the malic enzyme of other organisms.
Expression of the mleS gene in Escherichia coli results in malolactic activity.
- Language of Publication
- English
- Unique Identifier
- 94178715
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full text for this document
- MeSH Heading (Major)
- Lactococcus lactis|EN/*GE; Malate Dehydrogenase|*GE/ME
- MeSH Heading
- Amino Acid Sequence; Animal; Base Sequence; Cloning, Molecular; DNA,
Bacterial; Escherichia coli; Human; Molecular Sequence Data; Open Reading
Frames; Polymerase Chain Reaction; Restriction Mapping; Sequence Homology, Amino
Acid
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0378-1097
- Country of Publication
- NETHERLANDS
Record 67 from database: MEDLINE
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- Title
- A comparative study on the transport of L(-)malic acid and other short-chain
carboxylic acids in the yeast Candida utilis: evidence for a general organic
acid permease.
- Author
- Cássio F; Leão C
- Address
- Laboratory of Biology, University of Minho, Braga, Portugal.
- Source
- Yeast, 1993 Jul, 9:7, 743-52
- Abstract
- Cells of the yeast Candida utilis grown in medium with short-chain mono-,
di- or tricarboxylic acids transported L(-)malic acid by two transport systems
at pH 3.0. Results indicate that probably a proton symport for the ionized form
of the acid and a facilitated diffusion for the undissociated form were present.
Dicarboxylic acids such as succinic, fumaric, oxaloacetic and alpha-ketoglutaric
acids were competitive inhibitors of the malic acid for the high-affinity
system, suggesting that these acids used the same transport system. In turn,
competitive inhibition uptake studies of labelled carboxylic acid in the
low-affinity range indicated that this system was non-specific and able to
accept not only carboxylic (mono-, di- or tri-) acids but also some amino acids.
Additionally, under the same growth conditions, C. utilis produced two mediated
transport systems for lactic acid: a proton symport for the anionic form which
appeared to be a common monocarboxylate carrier and a facilitated diffusion
system for the undissociated acid displaying a substrate specificity similar to
that observed for the low-affinity dicarboxylic acid transport. The mediated
carboxylic acid transport systems were inducible and subjected to repression by
glucose. In glucose-grown cells the undissociated dicarboxylic acids entered the
cells slowly by simple diffusion. Repressed glucose-grown cells were only able
to produce both transport systems if an inducer, at low concentration (0.5%,
w/v), was present during starvation in buffer. This process was inhibited by the
presence of cycloheximide indicating that induction requires de novo protein
synthesis. If a higher acid concentration was used, only the low-affinity
transport system was detectable, showing that the high-affinity system was also
repressed by high concentrations of the inducer.
- Language of Publication
- English
- Unique Identifier
- 93377411
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full text for this document
- MeSH Heading (Major)
- Candida|EN/*ME; Carboxylic Acids|*ME; Permeases|*ME
- MeSH Heading
- Biological Transport|PH; Comparative Study; Dicarboxylic Acids|ME;
Lactates|ME; Malates|ME; Reproducibility of Results; Substrate Specificity;
Succinates|ME; Support, Non-U.S. Gov't; Tricarboxylic Acids|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0749-503X
- Country of Publication
- ENGLAND
Record 68 from database: MEDLINE
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- Title
- Taste responses of neurons in the nucleus of the solitary tract of awake
rats: an extended stimulus array.
- Author
- Nakamura K; Norgren R
- Address
- Department of Behavioral Science, College of Medicine, Pennsylvania State
University, Hershey 17033.
- Source
- J Neurophysiol, 1993 Sep, 70:3, 879-91
- Abstract
- 1. Fifty-seven taste neurons were isolated in the nucleus solitary tract
(NST) and tested with 15 sapid chemicals. On average, NST neurons responded well
to NaCl, sucrose, monosodium L-glutamate (MSG), NaNO3, and glycine (mean =
8.2-11.0 spikes/s). Mean responses to KCl, NH4Cl, HCl, malic acid, and quinine
HCl (QHCl) were low (mean = 0.7-2.9). The average responses to the other stimuli
(citric acid, MgCl2, fructose, maltose, and polycose) fell between these
extremes (mean = 4.3-5.1). 2. On the basis of the largest response to the four
standard stimuli, the neurons were classified as follows: 15 NaCl-best, 23
sucrose-best, 17 citric acid-best, and 2 QHCl-best. 3. The NaCl-best neurons
responded robustly and nearly equally to the three sodium salts (mean =
15.7-20.8) but much less so and more variably to the nonsodium, chloride salts
(mean = -0.1-4.6). Sucrose-best neurons responded strongly to sucrose, glycine,
and MSG (mean = 13.7-17.8), but only moderately to the other sugars (fructose
and maltose) and to polycose (mean = 8.4, 9.8, and 8.8, respectively). 4. Citric
acid-best neurons responded moderately to citric and malic acid (mean = 9.4 and
4.7), but less so to HCl (mean = 3.1). The two QHCl-best neurons responded
moderately to QHCl and MgCl2 (mean = 12.0 and 9.5), but weakly or not at all to
the other stimuli (mean = -1.1-3.1). 5. Unlike parabrachial taste neurons, none
of the medullary taste cells responded specifically to Cl(-)-containing
chemicals. The responses that did occur to nonsodium salts were weak and
variable and often occurred in either citric acid-best or QHCl-best neurons,
rather than in those that responded vigorously to sodium salts. Similar
relationships have been observed in anesthetized preparations. 6. A hierarchical
cluster analysis for 57 neurons across 15 stimuli produced four second-order
clusters that consisted primarily of NaCl-best, sucrose-best, citric acid-best,
and QHCl-best neurons, respectively. Although the analysis for neurons produced
only four such clusters, a similar analysis for the 15 stimuli separated the
sodium salts (NaCl and NaNO3), nonsodium salts (KCL, NH4Cl, and MGCl2,
sweeteners (sucrose, maltose, fructose, and glycine), acids (citric acid and
malic acid), and QHCl. 7. Monosodium glutamate activated both NaCl-best and
sucrose-best neurons, but the stimulus analysis clumped it with the sodium
salts.(ABSTRACT TRUNCATED AT 400 WORDS)
- Language of Publication
- English
- Unique Identifier
- 94045876
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full text for this document
- MeSH Heading (Major)
- Arousal|*PH; Attention|*PH; Medulla Oblongata|*PH; Pons|*PH; Synaptic
Transmission|*PH; Taste|*PH
- MeSH Heading
- Animal; Citrates; Cluster Analysis; Comparative Study; Evoked Potentials,
Somatosensory|PH; Factor Analysis, Statistical; Male; Neural Inhibition|PH;
Neurons|PH; Quinine; Rats; Rats, Sprague-Dawley; Saline Solution, Hypertonic;
Sucrose; Support, Non-U.S. Gov't; Support, U.S. Gov't, P.H.S.; Taste
Threshold|PH
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-3077
- Country of Publication
- UNITED STATES
Record 69 from database: MEDLINE
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- Title
- Effect of methotrexate (MTX) on NAD(P)+ dehydrogenases of HeLa cells: malic
enzyme, 2-oxoglutarate and isocitrate dehydrogenases.
- Author
- Caetano NN; Campello AP; Carnieri EG; Kluppel ML; Oliveira MB
- Address
- Departamento de BioquÆimica da Universidade Federal do ParanÆa, Curitiba,
Brasil.
- Source
- Cell Biochem Funct, 1997 Dec, 15:4, 259-64
- Abstract
- The effects of methotrexate (MTX) on oxygen uptake by permeabilized HeLa
cells were evaluated. MTX did not inhibit state III respiration when the
oxidizable substrate was succinate, but when the substrates were 2-oxoglutarate
or isocitrate the respiration decreased about 50 per cent at 1.0 mM
concentration of the drug. This effect was explained by inhibition of
2-oxoglutarate and isocitrate dehydrogenases by MTX. No effect was observed on
succinate dehydrogenase. An evaluation of the effects of MTX on malic enzyme
activity as measured by pyruvate plus lactate production in intact cells
supplied with malate showed a decrease of about 40 per cent in metabolite
production using 0.4 mM MTX. HeLa cell malic enzyme, as observed for other
tumour cells, is compartmentalized in mitochondria and cytosol, and is another
example of a dehydrogenase inhibited by MTX.
- Language of Publication
- English
- Unique Identifier
- 98077821
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full text for this document
- MeSH Heading (Major)
- Antimetabolites, Antineoplastic|*PD; Methotrexate|*PD; Oxidoreductases|*ME
- MeSH Heading
- Hela Cells; Human; Isocitrate Dehydrogenase|ME; Ketoglutarate Dehydrogenase
Complex|ME; Lactic Acid|ME; Malate Dehydrogenase|ME; Mitochondria|DE/EN; NADPH
Dehydrogenase|ME; Oxygen Consumption|DE; Pyruvic Acid|ME; Support, Non-U.S.
Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0263-6484
- Country of Publication
- ENGLAND
Record 70 from database: MEDLINE
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- Title
- Production of succinic acid through overexpression of NAD(+)-dependent malic
enzyme in an Escherichia coli mutant.
- Author
- Stols L; Donnelly MI
- Address
- Environmental Research Division, Argonne National Laboratory, Illinois
60439, USA.
- Source
- Appl Environ Microbiol, 1997 Jul, 63:7, 2695-701
- Abstract
- NAD(+)-dependent malic enzyme was cloned from the Escherichia coli genome by
PCR based on the published partial sequence of the gene. The enzyme was
overexpressed and purified to near homogeneity in two chromatographic steps and
was analyzed kinetically in the forward and reverse directions. The Km values
determined in the presence of saturating cofactor and manganese ion were 0.26 mM
for malate (physiological direction) and 16 mM for pyruvate (reverse direction).
When malic enzyme was induced under appropriate culture conditions in a strain
of E. coli that was unable to ferment glucose and accumulated pyruvate,
fermentative metabolism of glucose was restored. Succinic acid was the major
fermentation product formed. When this fermentation was performed in the
presence of hydrogen, the yield of succinic acid increased. The constructed
pathway represents an alternative metabolic route for the fermentative
production of dicarboxylic acids from renewable feedstocks.
- Language of Publication
- English
- Unique Identifier
- 97355935
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full text for this document
- MeSH Heading (Major)
- Escherichia coli|*GE/*ME; Malate Dehydrogenase|*GE/IP/*ME; Succinates|*ME
- MeSH Heading
- Amino Acid Sequence; Base Sequence; Cloning, Molecular; Fermentation; Gene
Expression; Glucose|ME; Hydrogen|ME; Kinetics; Malates|ME; Manganese|ME;
Molecular Sequence Data; Pyruvic Acid|ME; Support, U.S. Gov't, Non-P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0099-2240
- Country of Publication
- UNITED STATES
Record 71 from database: MEDLINE
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- Title
- Inducible overexpression of the FUM1 gene in Saccharomyces cerevisiae:
localization of fumarase and efficient fumaric acid bioconversion to L-malic
acid.
- Author
- Peleg Y; Rokem JS; Goldberg I; Pines O
- Address
- Department of Applied Microbiology, Hebrew University, Jerusalem, Israel.
- Source
- Appl Environ Microbiol, 1990 Sep, 56:9, 2777-83
- Abstract
- Cloning of the Saccharomyces cerevisiae FUM1 gene downstream of the strong
GAL10 promoter resulted in inducible overexpression of fumarase in the yeast.
The overproducing strain exhibited efficient bioconversion of fumaric acid to
L-malic acid with an apparent conversion value of 88% and a conversion rate of
80.4 mmol of fumaric acid/h per g of cell wet weight, both of which are much
higher than parameters known for industrial bacterial strains. The only product
of the conversion reaction was L-malic acid, which was essentially free of the
unwanted by-product succinic acid. The GAL10 promoter situated upstream of a
promoterless FUM1 gene led to production and correct distribution of the two
fumarase isoenzyme activities between cytosolic and mitochondrial subcellular
fractions. The amino-terminal sequence of fumarase contains the mitochondrial
signal sequence since (i) 92 of 463 amino acid residues from the amino terminus
of fumarase are sufficient to localize fumarase-lacZ fusions to mitochondria and
(ii) fumarase and fumarase-lacZ fusions lacking the amino-terminal sequence are
localized exclusively in the cytosol. The possibility that both mitochondrial
and cytosolic fumarases are derived from the same initial translation product is
discussed.
- Language of Publication
- English
- Unique Identifier
- 91112716
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full text for this document
- MeSH Heading (Major)
- Fumarate Hydratase|BI/*GE; Genes, Fungal|*; Saccharomyces cerevisiae|*GE/ME
- MeSH Heading
- Cloning, Molecular; Enzyme Induction; Fumarates|ME; Gene Expression;
Malates|ME; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0099-2240
- Country of Publication
- UNITED STATES
Record 72 from database: MEDLINE
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- Title
- Regulation of malic-enzyme-gene expression by cAMP and retinoic acid in
differentiating brown adipocytes.
- Author
- Hernandez A; Garcia Jimenez C; Santisteban P; Obregon MJ
- Address
- Instituto de Investigaciones BiomÆedicas, C. S. I. C., Madrid, Spain.
- Source
- Eur J Biochem, 1993 Jul, 215:2, 285-90
- Abstract
- Brown adipose tissue (BAT) is composed of highly specialized cells, whose
main function is to produce heat under adrenergic stimulation, uncoupling
oxidative phosphorylation. For this function, lipogenesis must be accurately
regulated. Malic enzyme has a central role in lipogenesis and is strongly
expressed in brown adipocytes. In this work, we study the modulation by
adrenergic stimuli, cAMP effectors and retinoic acid on the induction produced
by insulin and 3,5,3'-triiodothyronine on malic-enzyme-gene expression. Primary
cultures of differentiating brown adipocytes have been used. The results
obtained demonstrate that physiological doses of norepinephrine do not modify
malic-enzyme mRNA levels when acting alone, but considerably reduce the
induction produced by insulin, 3,5,3'-triiodothyronine or both together. Other
cAMP inducers such as glucagon, forskolin or 8-bromo-cAMP, greatly inhibit both,
basal and 3,5,3'-triiodothyronine-induced malic-enzyme-gene gene expression.
Retinoic acid abolishes basal and also inhibits 3,5,3'-triiodothyronine-induced
malic-enzyme-gene expression.
- Language of Publication
- English
- Unique Identifier
- 93345514
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full text for this document
- MeSH Heading (Major)
- Adipose Tissue|CY/DE/*EN; Cyclic AMP|*PH; Gene Expression Regulation,
Enzymologic|*DE; Malate Dehydrogenase|BI/*GE; Tretinoin|*PD
- MeSH Heading
- Animal; Cell Differentiation; Cells, Cultured; Forskolin|PD; Glucagon|PD;
Insulin|PD; Norepinephrine|PD; Rats; RNA, Messenger|GE/ME; Support, Non-U.S.
Gov't; Triiodothyronine|PD; 8-Bromo Cyclic Adenosine Monophosphate|PD
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-2956
- Country of Publication
- GERMANY
Record 73 from database: MEDLINE
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- Title
- Low-dose almitrine bismesylate enhances hypoxic pulmonary vasoconstriction
in closed-chest dogs.
- Author
- Chen L; Miller FL; Clarke WR; Clergue FX; Marshall C; Marshall BE
- Address
- Center for Research in Anesthesia, University of Pennsylvania School of
Medicine, Philadelphia 19104.
- Source
- Anesth Analg, 1990 Nov, 71:5, 475-83
- Abstract
- The effect of almitrine bismesylate on the hypoxic pulmonary vasoconstrictor
response was studied in six closed-chest dogs anesthetized with pentobarbital
and paralyzed with pancuronium. The right lung was ventilated continuously with
100% O2; the left lung was ventilated either with 100% O2 ("hyperoxia") or with
an hypoxic gas mixture ("hypoxia": end-tidal oxygen tension = 60.3 +/- 0.6 mm
Hg). On two consecutive days, each dog received either almitrine (Vectarion,
Servier Lab) or malic acid. Consecutive almitrine doses of 0.003, 0.03, 0.3, and
3.0 micrograms.kg-1.min-1, or the equivalent volumes of malic acid without
almitrine, were administered intravenously as a constant peripheral infusion for
15 min. Percent blood flow to each lung was calculated based on a variation of
the traditional shunt equation. The change in percent left lung blood flow
(delta %QL-VA) increased significantly between the hypoxia-no drug and the
hypoxia-almitrine (3.0 micrograms.kg-1.min-1) phase. No significant changes
occurred during the other almitrine doses or the respective malic acid control
phases. The change in arterial oxygen tension (delta PaO2) also increased
significantly between the hypoxia-no drug and the hypoxia-almitrine (3.0
micrograms.kg-1.min-1) phase. No significant changes occurred during the other
almitrine doses or the respective malic acid control phases. It is concluded
that in dogs low-dose almitrine enhances hypoxic pulmonary vasoconstriction and
that this enhancement is dose-related.
- Language of Publication
- English
- Unique Identifier
- 91023507
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full text for this document
- MeSH Heading (Major)
- Almitrine|*AD; Anoxia|*PP; Lung|*BS; Vasoconstriction|*DE/PH
- MeSH Heading
- Animal; Comparative Study; Dogs; Dose-Response Relationship, Drug; Female;
Infusions, Intravenous; Malates|AD; Stimulation, Chemical; Support, Non-U.S.
Gov't; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0003-2999
- Country of Publication
- UNITED STATES
Record 74 from database: MEDLINE
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- Title
- C4 acid decarboxylation and photosynthesis in bundle sheath cells of
NAD-malic enzyme-type C4 plants: mechanism and the role of malate and
orthophosphate.
- Author
- Furbank RT; Agostino A; Hatch MD
- Address
- CSIRO Division of Plant Industry, Canberra ACT, Australia.
- Source
- Arch Biochem Biophys, 1990 Feb, 276:2, 374-81
- Abstract
- The mechanism and possible regulation of C4 acid decarboxylation in
NAD-malic enzyme-type C4 plants was studied using isolated bundle sheath cells
and mitochondria from Panicum miliaceum. Rates of C4 acid-dependent
photosynthetic O2 evolution equalled those observed with saturating NaHCO3; the
rates ranged from 3 to 5 mumol min-1 (mg chlorophyll)-1. C4 acid-dependent O2
evolution required the addition of aspartate and 2-oxoglutarate (as a source of
oxaloacetate) and also malate and orthophosphate. C4 acid decarboxylation by
both isolated cells and mitochondria, measured as pyruvate production, also
required all four of these components. The scheme previously proposed to account
for aspartate decarboxylation in NAD-malic enzyme-type C4 plants does not
envisage a role for externally derived malate. However, the mandatory
requirement for malate (with orthophosphate), together with the observation that
C4 acid decarboxylation is blocked by an inhibitor of the mitochondrial
dicarboxylate transporter, suggests that a net flux of malate from outside the
mitochondria is required to sustain this process. Arsenate was found to
substitute for orthophosphate favoring a role for orthophosphate in malate
transport rather than a metabolic one. The results are discussed in terms of
likely mitochondrial metabolite transport mechanisms and regulation of the C4
acid decarboxylation process.
- Language of Publication
- English
- Unique Identifier
- 90165430
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full text for this document
- MeSH Heading (Major)
- Carboxylic Acids|*ME; Malate Dehydrogenase|*ME; Malates|*ME/PD;
Phosphates|*ME; Photosynthesis|*; Plants|CY/EN/*ME
- MeSH Heading
- Cytosol|ME; Kinetics; Mitochondria|ME; Models, Biological; NAD|ME;
Pyruvates|ME; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0003-9861
- Country of Publication
- UNITED STATES
Record 75 from database: MEDLINE
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- Title
- Cloning and nucleotide sequence of a full-length cDNA encoding Ascaris suum
malic enzyme.
- Author
- Kulkarni G; Cook PF; Harris BG
- Address
- Department of Biochemistry & Molecular Biology, Texas College of
Osteopathic Medicine/University of North Texas, Fort Worth 76107.
- Source
- Arch Biochem Biophys, 1993 Jan, 300:1, 231-7
- Abstract
- The nucleotide sequence of a full-length cDNA encoding NAD(+)-malic enzyme
from the parasitic nematode Ascaris suum was determined. The entire sequence of
2269 bases comprises a 5'-leader, a single open reading frame of 1851 bases, and
the complete 3'-noncoding region of 340 bases. The first 12 amino acids of the
translated sequence are hydrophobic, typical of mitochondrial translocation
signals, and do not appear in the purified mature protein. The mature protein
contains 605 amino acids and has a molecular mass of 68,478 Da. The amino acid
sequences of tryptic peptides from the purified protein and also the N-terminal
sequence show excellent correspondence with the translated nucleotide sequence.
Comparison of the amino acid sequence of the ascarid protein with the human and
rat liver NAD(+)-malic enzymes reveals highly conserved regions interrupted with
long stretches of lesser homologous sequences. Structural motifs such as the
putative nucleotide binding domains and also the malate binding site are clearly
identified by alignment of the three protein sequences.
- Language of Publication
- English
- Unique Identifier
- 93143319
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full text for this document
- MeSH Heading (Major)
- Ascaris suum|*EN/*GE; DNA|*GE; Malate Dehydrogenase|*GE
- MeSH Heading
- Amino Acid Sequence; Animal; Base Sequence; Cloning, Molecular; Comparative
Study; Gene Library; Human; Mice; Molecular Sequence Data; Peptide Fragments|IP;
Rats; Sequence Homology, Amino Acid; Support, Non-U.S. Gov't; Support, U.S.
Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0003-9861
- Country of Publication
- UNITED STATES
Record 76 from database: MEDLINE
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- Title
- Changes in the hepatic levels of messenger ribonucleic acid for malic enzyme
during induction by thyroid hormone or diet.
- Author
- Towle HC; Mariash CN; Oppenheimer JH
- Address
-
- Source
- Biochemistry, 1980 Feb, 19:3, 579-85
- Abstract
- Levels of hepatic messenger ribonucleic acid (mRNA) for malic enzyme
[L-malate:NADP oxidoreductase (decarboxylating), EC 1.1.1.40] were quantitated
in different dietary and hormonal states of the rat. Polysomal or total cellular
poly(A)-containing RNA was translated in the rabbit reticulocyte lysate system,
which had been treated to reduce endogenous mRNA activity. The relative level of
incorporation of radiolabeled amino acid into malic enzyme was determined by
immunoprecipitation with antibody to malic enzyme and formaldehyde-fixed
Staphylococcus aureus (Cowens I strain) as an immunoadsorbent. The
immunoprecipitated product comigrated with purified malic enzyme on sodium
dodecyl sulfate--polyacrylamide gel electrophoresis. No malic enzyme was
detected when nonspecific antisera or an excess of unlabeled malic enzyme was
added during immunoprecipitation. The level of malic enzyme mRNA was found to
markedly increase relative to euthyroid, chow-fed rats when the animal was
either fed a high carbohydrate, fat-free diet or made hyperthyroid. Animals
receiving both treatments had a further increase in mRNA activity to a level
which was approximately 0.2% of the total incorporation of [3H]leucine. Levels
of malic enzyme activity and the relative rate of synthesis were found to
increase roughly in proportion to mRNA levels in these three states. Thus, the
induction of malic enzyme by thyroid hormone or high carbohydrate, fat-free diet
is due largely to an increase in the mRNA coding for this enzyme.
- Language of Publication
- English
- Unique Identifier
- 80130551
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full text for this document
- MeSH Heading (Major)
- Dietary Carbohydrates|*PD; Liver|DE/*EN; Malate Dehydrogenase|*BI; RNA,
Messenger|*ME; Translation, Genetic|*DE; Triiodothyronine|*PD
- MeSH Heading
- Animal; Enzyme Induction|DE; Hyperthyroidism|EN; Male; Rabbits; Rats;
Reticulocytes|ME; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2960
- Country of Publication
- UNITED STATES
Record 77 from database: MEDLINE
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- Title
- Relationship of malic enzyme activity to fatty acid synthesis and the
pathways of glucose catabolism in developing rat liver.
- Author
- Madvig P; Abraham S
- Address
-
- Source
- J Nutr, 1980 Jan, 110:1, 90-9
- Abstract
- The rates of fatty acid synthesis and the activity of several enzymes
involved in lipid and carbohydrate metabolism were determined in livers from
fetal, suckling, weanling and maternal rats. An estimate of the proportion of
glucose catabolized via the pentose phosphate cycle and the Embden-Meyerhoff
pathway was made using 14C- and 3H-labeled glucose. The contribution of pentose
phosphate cycle-generated reducing equivalents to fatty acid synthesis was
assessed using glucose-3-3H. Developmental changes in the activity of hepatic
malic enzyme were not related to developmental changes in the rate of fatty acid
synthesis as might be expected if this enzyme functioned to provide NADPH for
fatty acid synthesis. Malic enzyme activity did not correlate with pentose
phosphate cycle activity or with utilization for fatty acid synthesis of NADPH
generated via this pathway.
- Language of Publication
- English
- Unique Identifier
- 80117244
Order
full text for this document
- MeSH Heading (Major)
- Fatty Acids|*BI; Glucose|*ME; Liver|GD/*ME; Malate Dehydrogenase|*ME
- MeSH Heading
- Acetates|ME; Aging; Animal; Diet; Female; Fetus; Lactation; Male;
Pentosephosphates|ME; Pregnancy; Rats; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-3166
- Country of Publication
- UNITED STATES
Record 78 from database: MEDLINE
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- Title
- Effects of dietary proteins on lipogenic enzymes in rat liver.
- Author
- Iritani N; Nagashima K; Fukuda H; Katsurada A; Tanaka T
- Address
-
- Source
- J Nutr, 1986 Feb, 116:2, 190-7
- Abstract
- When fasted rats were fed fat-free diets containing various sources of
protein for 3 d, the activities of liver glucose-6-phosphate dehydrogenase,
malic enzyme, acetyl-CoA carboxylase and fatty acid synthetase were markedly
lower in rats fed soybean protein or gluten than in those fed casein or fish
protein. Since malic enzyme mRNA activity was not low in the soybean protein-fed
animals, the translation of malic enzyme appears to be suppressed by dietary
soybean protein. The incorporation of tritiated water into liver fatty acids was
significantly lower in animals fed soybean protein than in those fed casein. The
triglyceride levels in plasma and especially in liver were also lower in the
groups fed soybean and gluten than in the groups fed casein and fish. In
addition, when dietary soybean protein was replaced with amino acids to simulate
casein or soybean protein, the effects on the levels of lipogenic enzymes were
still found but were not as great. Thus, some effects can be ascribed to the
protein itself and some to the amino acid composition of the diet.
- Language of Publication
- English
- Unique Identifier
- 86114305
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full text for this document
- MeSH Heading (Major)
- Dietary Proteins|*PD; Liver|*EN/ME
- MeSH Heading
- Acetyl-CoA Carboxylase|ME; Amino Acids|PD; Animal; Caseins|PD; Dietary
Fats|AD; Fatty Acid Synthetase Complex|ME; Fatty Acids|ME; Fish Products;
Glucosephosphate Dehydrogenase|ME; Gluten|PD; Malate Dehydrogenase|ME; Male;
Rats; Rats, Inbred Strains; RNA, Messenger|GE; Soybeans; Translation, Genetic;
Triglycerides|ME; Vegetable Proteins|PD
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0022-3166
- Country of Publication
- UNITED STATES
Record 79 from database: MEDLINE
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- Title
- Regulation of gene expression for lipogenic enzymes in the liver and adipose
tissue of hereditary hypertriglyceridemic, insulin-resistant rats: effect of
dietary sucrose and marine fish oil.
- Author
- Seböková E; Klimes I; Gasperíková D; Bohov P; Langer P; Lavau M; Clandinin
MT
- Address
- Institute of Experimental Endocrinology, Slovak Academy of Sciences,
Bratislava, Slovak Republic. sebok@uee.savba.sk
- Source
- Biochim Biophys Acta, 1996 Sep, 1303:1, 56-62
- Abstract
- Hypertriglyceridemia is closely linked to insulin resistance. Increased
dietary intake of n-3 polyunsaturated fatty acids reverses both
hypertriglyceridemia and insulin resistance. To evaluate molecular mechanisms
responsible for the hypotriglyceridemic effects of n-3 polyunsaturated fatty
acids, the expression of genes for lipogenic enzymes in liver and white and
brown adipose tissue was estimated in hereditary hypertriglyceridemic rats which
underwent an euglycemic hyperinsulinemic clamp. Before the clamp, animals were
fed a basal or a high (63%) sucrose diet with or without fish oil for two weeks.
Results were compared to data obtained from control animals subjected to the
identical protocol. In hereditary hypertriglyceridemic rats, gene expression for
malic enzyme was increased in liver and in brown adipose tissue but not in white
adipose tissue. The high sucrose diet raised malic enzyme mRNA levels in liver
of both hereditary hypertriglyceridemic and control rats, and this effect was
more pronounced in brown adipose tissue. Supplementing the high sucrose diet
with fish oil led to a suppression of malic enzyme gene expression in liver and
brown adipose tissue of control rats. However, this inhibitory effect was not as
pronounced in the hereditary hypertriglyceridemic rats. Raised levels of fatty
acid synthase mRNA in liver and brown adipose tissue of control rats fed high
sucrose diet were suppressed by consumption of diet high in n-3 fatty acids. On
the other hand, in hereditary hypertriglyceridemic rats fed high sucrose diet,
fish oil supplementation failed to suppress increased levels of fatty acid
synthase mRNA in liver and in brown adipose tissue. It appears that hereditary
hypertriglyceridemic rats have elevated levels of mRNA for lipogenic enzymes in
liver and brown adipose tissue and dietary control leading to an alteration of
hypertriglyceridemia influences gene expression of lipogenic enzymes only under
special dietary circumstances.
- Language of Publication
- English
- Unique Identifier
- 96413699
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full text for this document
- MeSH Heading (Major)
- Adipose Tissue|*EN; Diet|*; Gene Expression Regulation, Enzymologic|*;
Hypertriglyceridemia|*CN/EN; Lipids|*BI; Liver|*EN
- MeSH Heading
- Animal; Antilipemic Agents|PD; Comparative Study; Dietary Carbohydrates|PD;
Dietary Fats, Unsaturated|PD; Fatty Acid Synthetase Complex|BI; Fish Oils|PD;
Glucose Clamp Technique; Insulin Resistance; Malate Dehydrogenase|BI; Male;
Rats; Rats, Mutant Strains; Sucrose|PD; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3002
- Country of Publication
- NETHERLANDS
Record 80 from database: MEDLINE
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- Title
- Duck liver malic enzyme: sequence of a tryptic peptide containing the
cysteine residue labeled by the substrate analog bromopyruvate.
- Author
- Satterlee J; Hsu RY
- Address
- Health Science Center, State University of New York, Syracuse.
- Source
- Biochim Biophys Acta, 1991 Sep, 1079:3, 247-52
- Abstract
- Malic enzyme of duck liver is alkylated by bromopyruvate with
half-of-the-sites stoichiometry, and with accompanying loss of oxidative
decarboxylase and enhancement of pyruvate reductase activities as was previously
shown for the pigeon enzyme (Hsu, R.Y. (1982) Mol. Cell. Biochem. 43, 3-26). In
the present work, the alkylated enzyme is shown to bind NADPH, but not L-malate
in the presence of MnCl2, indicating impairment of the enzyme site for the
substrate and/or divalent metal. The enzyme was differentially labeled by
3-bromo-1-[14C]-pyruvate and digested with TPCK-treated trypsin. Two peptides
bearing the susceptible residue were purified by high-performance liquid
chromatography and sequenced. Peptide II has the sequence of
FMPIVYTPTVGLAXQQYGLAFR, corresponding to residues 86-107 (temporary numbering)
of the duck enzyme; cysteine-99(x) is not detected, indicating that it is the
target of modification by bromopyruvate. Peptide I is a truncated form of
peptide II lacking five amino acid residues at the C-terminal. Cysteine-99 is
conserved in malic enzymes from duck, rat, mouse, maize, human, Flaveria
trinervia and Bacillus stearothermophilus.
- Language of Publication
- English
- Unique Identifier
- 92002141
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full text for this document
- MeSH Heading (Major)
- Liver|*EN; Malate Dehydrogenase|GE/IP/*ME; Pyruvates|*ME
- MeSH Heading
- Affinity Labels; Amino Acid Sequence; Animal; Comparative Study; Ducks;
Kinetics; Molecular Sequence Data; Peptide Fragments|IP/ME; Sequence Homology,
Nucleic Acid; Spectrometry, Fluorescence; Support, Non-U.S. Gov't; Support, U.S.
Gov't, P.H.S.; Trypsin|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3002
- Country of Publication
- NETHERLANDS
Record 81 from database: MEDLINE
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- Title
- The NADPH-producing pathways (pentose phosphate and malic enzyme) are
regulated by the NADPH consumption in rat mammary gland.
- Author
- Revilla E; Fabregat I; Santa María C; Machado A
- Address
- Departamento de BioquÆimica, Facultad de Farmacia, Universidad de Sevilla,
Spain.
- Source
- Biochem Int, 1987 May, 14:5, 957-62
- Abstract
- We have studied the changes in the activity of the pentose phosphate cycle
and the malic enzyme produced by the activation or inhibition of different
NADPH-consuming pathways. Kynurenate, an acetyl-CoA-carboxylase inhibitor
produced a decrease in the flux through the NADPH-producing pathways pentose
phosphate cycle and malic enzyme. Acini (isolated from mammary gland) incubated
in the presence of ter-butyl-hydroperoxide, a compound which is metabolized via
a NADPH-consuming pathway, showed a substantial increase in the pentose
phosphate cycle and the malic enzyme pathways.
- Language of Publication
- English
- Unique Identifier
- 88309169
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full text for this document
- MeSH Heading (Major)
- Malate Dehydrogenase|*ME; Mammae|EN/*ME; NADP|AI/*ME; Pentosephosphate
Pathway|*
- MeSH Heading
- Animal; Enzyme Activation; Female; In Vitro; Kynurenic Acid|PD;
Peroxides|PD; Rats; Rats, Inbred Strains; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0158-5231
- Country of Publication
- AUSTRALIA
Record 82 from database: MEDLINE
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full text for this document
- Title
- Levels of mRNAs coding for lipogenic enzymes in rat lung upon fasting and
refeeding and during perinatal development [published erratum appears in Biochim
Biophys Acta 1990 Feb 6;1042(2):269]
- Author
- Batenburg JJ; Whitsett JA
- Address
- Laboratory of Veterinary Biochemistry, Utrecht University, The Netherlands.
- Source
- Biochim Biophys Acta, 1989 Dec, 1006:3, 329-34
- Abstract
- The relative amounts of mRNAs coding for fatty-acid synthase (EC 2.3.1.85),
acetyl-CoA carboxylase (EC 6.4.1.2), ATP citrate lyase (EC 4.1.3.8) and malic
enzyme (EC 1.1.1.40) were determined in lungs and livers of adult rats that were
normally fed, starved for 48 h or starved for 48 h and subsequently refed for 72
h with a carbohydrate-rich, fat-free diet. In the liver, starvation caused a
small decrease in the relative abundance of the mRNAs which was not
statistically significant. Subsequent refeeding caused a statistically
significant increase in mRNAs for all of the enzymes studied. In the lung, no
significant changes were found, indicating that the regulation of the abundance
of mRNAs encoding the lipogenic enzymes in the lung differs from that in the
liver. In the developing rat lung, mRNA for fatty-acid synthase increased 3-fold
in abundance between fetal days 18 and 20 and decreased directly after birth (at
day 22 of gestation). A similar pattern was observed for ATP citrate lyase mRNA.
The level of acetyl-CoA carboxylase mRNA decreased significantly after birth.
These observations indicate that in perinatal rat lungs, pretranslational
regulation is involved in the control of the synthesis of these enzymes. The
abundance of acetyl-CoA carboxylase mRNA did not change in the prenatal period,
a time during which the specific activity of this enzyme increases. This lack of
correlation between the specific activity of acetyl-CoA carboxylase and the
abundance of its mRNA may indicate that translational regulation of the
synthesis of the enzyme or post-synthetic regulatory effects on enzyme molecules
are involved in the control of this enzyme in the prenatal period. No changes in
the abundance of lung malic enzyme mRNAs were observed throughout the perinatal
period.
- Language of Publication
- English
- Unique Identifier
- 90089390
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full text for this document
- MeSH Heading (Major)
- Animals, Newborn|*ME; Fasting|*; Food|*; Lipids|*BI; Lung|EM/*EN/GD; RNA,
Messenger|*ME
- MeSH Heading
- Acetyl-CoA Carboxylase|GE; Animal; ATP Citrate (pro-S)-Lyase|GE; Fatty Acid
Synthetase Complex|GE; Gene Expression Regulation; Gestational Age; Liver|EN;
Malate Dehydrogenase|GE; Male; Nucleic Acid Hybridization; Rats; Rats, Inbred
Strains; Support, Non-U.S. Gov't; Translation, Genetic
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3002
- Country of Publication
- NETHERLANDS
Record 83 from database: MEDLINE
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- Title
- Effects of androgens, prolactin and bromocriptine on seminal vesicular
enzymes of the pyruvate malate cycle involved in lipogenesis in castrated mature
monkeys, Macaca radiata.
- Author
- Arunakaran J; Balasubramanian K; Srinivasan N; Aruldhas MM; Govindarajulu P
- Address
- Department of Endocrinology, University of Madras, Taramani, India.
- Source
- Int J Androl, 1988 Apr, 11:2, 133-9
- Abstract
- The interaction of androgens and prolactin, the major factors regulating the
male accessory sex organs, on the specific activity of seminal vesicular enzymes
of the pyruvate/malate cycle were studied in castrated mature monkeys.
Castration decreased the activity of these enzymes, including NADP+ isocitrate
dehydrogenase, ATP citrate lyase, malate dehydrogenase, malic enzyme and fatty
acid synthase. Testosterone propionate (TP)/dihydrotestosterone given as
replacement to castrates increased the activity of all these enzymes, except for
malate dehydrogenase. Prolactin restored normal activity of ATP citrate lyase,
malic enzyme and fatty acid synthase but not of isocitrate dehydrogenase and
malate dehydrogenase (MDH). Prolactin had a specific control over MDH. Moreover,
when prolactin was combined with androgens a further stimulatory influence was
observed on fatty acid synthase activity. In order to prove the direct influence
of prolactin on enzymes of the pyruvate/malate cycle, bromocriptine was
administered and this inhibited all of the enzymes. Thus prolactin was found to
have a direct, as well as a synergistic, action with androgens on enzymes of the
pyruvate/malate cycle in the seminal vesicles of monkeys.
- Language of Publication
- English
- Unique Identifier
- 88227020
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full text for this document
- MeSH Heading (Major)
- Androgens|*PD; Bromocriptine|*PD; Lipids|*BI; Prolactin|*PD; Seminal
Vesicles|DE/*EN
- MeSH Heading
- Animal; ATP Citrate (pro-S)-Lyase|ME; Fatty Acid Synthetase Complex|ME;
Isocitrate Dehydrogenase|ME; Macaca radiata; Malates|ME; Male; Orchiectomy;
Pyruvates|ME; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0105-6263
- Country of Publication
- DENMARK
Record 84 from database: MEDLINE
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- Title
- Effects of dietary nutrients on lipogenic enzyme and mRNA activities in rat
liver during induction.
- Author
- Katsurada A; Iritani N; Fukuda H; Noguchi T; Tanaka T
- Address
-
- Source
- Biochim Biophys Acta, 1986 Jul, 877:3, 350-8
- Abstract
- By feeding a carbohydrate diet (without protein) to fasted rats, malic
enzyme mRNA activity in the liver was increased to the level in rats fed a
carbohydrate and protein diet, whereas the enzyme activity itself was increased
to 60% of that level. It appears that malic enzyme mRNA activity was increased
by dietary carbohydrate, while dietary protein contributed to an increase in the
translation of mRNA. In the animals fed carbohydrate without protein,
glucose-6-phosphate dehydrogenase mRNA activity increased to 50% of the level in
rats fed the carbohydrate and protein diet, whereas the enzyme activity
increased to only 25%. By feeding a protein diet (without carbohydrate),
glucose-6-phosphate dehydrogenase activity increased to 65% of the level in rats
fed both carbohydrate and protein. This enzyme induction appears to be more
dependent on protein than carbohydrate. With the carbohydrate diet, acetyl-CoA
carboxylase was induced up to the level in the carbohydrate and protein diet
group, whereas fatty acid synthetase was induced to only 33%. Acetyl-CoA
carboxylase induction appears to be carbohydrate dependent. On the other hand,
isotopic leucine incorporation studies showed that the magnitudes of the enzyme
inductions caused by the dietary nutrients should be ascribed to the enzyme
synthesis rates rather than the degradation. By fat feeding, the mRNA activities
of malic enzyme and glucose-6-phosphate dehydrogenase were markedly decreased
along with the enzyme induction. Fat appears to reduce these enzyme inductions
before the translation of mRNA.
- Language of Publication
- English
- Unique Identifier
- 86270019
Order
full text for this document
- MeSH Heading (Major)
- Dietary Carbohydrates|*PD; Dietary Fats|*PD; Dietary Proteins|*PD;
Lipids|*BI; Liver|*EN; RNA, Messenger|*AN
- MeSH Heading
- Acetyl-CoA Carboxylase|BI; Animal; Enzyme Induction; Fatty Acid Synthetase
Complex|BI; Glucosephosphate Dehydrogenase|BI/GE; Malate Dehydrogenase|BI/GE;
Male; Rats; Rats, Inbred Strains; Time Factors
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3002
- Country of Publication
- NETHERLANDS
Record 85 from database: MEDLINE
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- Title
- CO2 is the inorganic carbon substrate of NADP malic enzymes from Zea mays
and from wheat germ.
- Author
- Häusler RE; Holtum JA; Latzko E
- Address
-
- Source
- Eur J Biochem, 1987 Mar, 163:3, 619-26
- Abstract
- NADP malic enzyme (EC 1.1.1.40) was extracted and partially purified from
the green leaves of Zea mays var. Felix and from wheat germ. The active
inorganic carbon species for both enzymes was, in contrast to an earlier report,
CO2 not HCO3-. The apparent Km, CO2 for the maize enzyme was 1.2 mM and the
apparent Km, CO2 for the wheat germ preparation was 4.2 mM under conditions of
substrate saturation, pH 7.3 and 17 degrees C. These observations support the
views that CO2, rather than HCO3- as has been suggested, is produced in
bundle-sheath chloroplasts and that the reaction mechanism catalysed by plant
cytosolic and chloroplastic NADP malic enzymes is similar to that proposed for
avian NADP malic enzymes.
- Language of Publication
- English
- Unique Identifier
- 87161864
Order
full text for this document
- MeSH Heading (Major)
- Carbon Dioxide|*ME; Malate Dehydrogenase|*ME; NADP|*ME; Plants|*EN
- MeSH Heading
- Carbonic Acid|ME; Corn; Hydrogen-Ion Concentration; Mathematics; Time
Factors; Wheat
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0014-2956
- Country of Publication
- GERMANY, WEST
Record 86 from database: MEDLINE
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- Title
- Hormonal and dietary regulation of hepatic enzymes in tumor-bearing rats.
- Author
- Greengard O; Cayanis E
- Address
-
- Source
- Cancer Res, 1983 Apr, 43:4, 1575-80
- Abstract
- Enzymes in the histologically normal liver of hosts of mammary carcinomas
were examined for their responsiveness to endocrine and dietary modulations.
Treatments with the developmental stimuli of alanine aminotransferase
(glucocorticoids) and of pyruvate kinase (thyroid hormone) which had no effect
in control adult rats raised the levels of these enzymes in the tumor-bearing
rats. The latter also showed a greater percentage of increase in malic enzyme
upon thyroid hormone administration than did control animals. The tumor-induced
increase in hexokinase remained unaltered by the various dietary treatments;
enzymes at subnormal levels were raised (glucokinase, malic enzymes, and
pyruvate kinase) or further decreased (alanine aminotransferase and ornithine
aminotransferase) by excessive carbohydrate intake in immature and adult
experimental rats. The normal upsurge of glucokinase and malic enzyme upon
weaning to the standard solid diet (from the relatively
low-carbohydrate-containing milk) was prevented by cancerous growth in the
organism. Similarly, the standard diet, which reversed within 2 days the partial
loss of these enzymes in normal adult rats fasted for 48 hr, had no restorative
effect on the essentially complete loss of the glucokinase and the very low
malic enzyme activity in the fasted tumor bearers. The results suggest that
failure in the dietary adaptations of hepatic enzymes as well as diminutions of
their basal levels contributes to the clinically observed abnormalities in the
glucose metabolism of cancer subjects.
- Language of Publication
- English
- Unique Identifier
- 83155230
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- MeSH Heading (Major)
- Alanine Transaminase|*ME; Glucokinase|*ME; Hexokinase|*ME; Liver|DE/*EN;
Malate Dehydrogenase|*ME; Mammary Neoplasms, Experimental|*EN;
Ornithine-Oxo-Acid Transaminase|*ME; Pyruvate Kinase|*ME; Transaminases|*ME
- MeSH Heading
- Animal; Histocytochemistry; Hydrocortisone|PD; Rats; Rats, Inbred F344;
Support, U.S. Gov't, P.H.S.; Thyroxine|PD; Triiodothyronine|PD
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0008-5472
- Country of Publication
- UNITED STATES
Record 87 from database: MEDLINE
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- Title
- The regulation of glucose and pyruvate formation from glutamine and
citric-acid-cycle intermediates in the kidney cortex of rats, dogs, rabbits and
guinea pigs.
- Author
- Watford M; Vinay P; Lemieux G; Gougoux A
- Address
-
- Source
- Biochem J, 1980 Jun, 188:3, 741-8
- Abstract
- The suppression by 3-mercaptopicolinate of gluconeogenesis from glutamine or
2-oxoglutarate in rat or dog kidney tubules did not affect the amount of these
substrates undergoing complete oxidation. Furthermore, 3-mercaptopicolinate
caused an accumulation of lactate in dog tubules. 3-Mercaptopicolinate abolished
both gluconeogenesis and substrate oxidation in tubules from rabbit and
guinea-pig kidney. These results imply the presence of an alternative pathway to
phosphoenolpyruvate carboxykinase/pyruvate kinase for the production of pyruvate
from citric-acid-cycle intermediates in the kidney cortex of rats and dogs but
not in that of rabbits or guinea pigs. Oxaloacetate decarboxylase (present in
the kidney cortex of all four species) or 'malic' enzyme (present in rat and dog
but absent in rabbit and guinea-pig kidney cortex) could function in this role.
Our observations indicate that 'malic' enzyme is probably implicated in this
phenomenon. The lactate production observed in dog tubules in the presence of
3-mercaptopicolinate can be suppressed when aspartate formation is inhibited by
2-amino-4-methoxy-trans-but-3-enoic acid. This suggests that the provision of
cytosolic NADH from citric-acid-cycle intermediates is facilitated by
accumulation of aspartate acting as a 'sink' for cytosolic oxaloacetate.
- Language of Publication
- English
- Unique Identifier
- 81133445
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- MeSH Heading (Major)
- Citric Acid Cycle|*; Gluconeogenesis|*/DE; Glutamine|*ME; Kidney
Cortex|DE/*ME; Pyruvates|*BI
- MeSH Heading
- Animal; Comparative Study; Dogs; Guinea Pigs; In Vitro; Ketoglutaric
Acids|ME; Kidney Tubules|DE/ME; Lactates|ME; Picolinic Acids|PD; Rabbits; Rats;
Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2936
- Country of Publication
- ENGLAND
Record 88 from database: MEDLINE
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- Title
- Insulin-mediated post-transcriptional regulation of hepatic malic enzyme and
albumin mRNAs.
- Author
- Davis BB; Magge S; Mucenski CG; Drake RL
- Address
- Department of Anatomy and Cell Biology, University of Cincinnati College of
Medicine, Ohio 45267-0521.
- Source
- Biochem Biophys Res Commun, 1988 Aug, 154:3, 1081-7
- Abstract
- Livers of insulin-treated diabetic rats accumulate albumin and malic enzyme
mRNAs at very different rates. We now report that in normal rats insulin directs
a specific increase in malic enzyme mRNA, while albumin mRNA levels remain
unaltered. These studies support the contention that insulin regulates the
accumulation of hepatic mRNAs in a highly specific manner. To evaluate whether
or not albumin and malic enzyme mRNA levels are determined by altered rates of
transcription, in vitro transcription assays were performed. The results of
these studies demonstrate that increased malic enzyme mRNA levels in
insulin-treated normal rats and increased malic enzyme and albumin mRNA levels
in insulin-treated diabetic rats do not involve altered rates of transcription
of the genetic sequences encoding these proteins. For these two specific
proteins, insulin mediates changes in mRNA levels by a post-transcriptional
mechanism.
- Language of Publication
- English
- Unique Identifier
- 88309087
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full text for this document
- MeSH Heading (Major)
- Diabetes Mellitus, Experimental|*ME; Insulin|*PD; Liver|DE/*ME; Malate
Dehydrogenase|*GE; RNA Processing, Post-Transcriptional|*DE; RNA,
Messenger|DE/*GE; Serum Albumin|*GE
- MeSH Heading
- Animal; Cell Nucleus|ME; Male; Nucleic Acid Hybridization; Rats; Rats,
Inbred Strains; Reference Values; Support, Non-U.S. Gov't; Support, U.S. Gov't,
P.H.S.; Transcription, Genetic|DE
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-291X
- Country of Publication
- UNITED STATES
Record 89 from database: MEDLINE
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- Title
- The pyruvate-proton exchange reaction of malic enzyme from pigeon liver.
- Author
- Bratcher SC; Hsu RY
- Address
-
- Source
- Biochim Biophys Acta, 1982 Mar, 702:1, 54-60
- Abstract
- Malic enzyme (L-malate:NADP+ oxidoreductase (decarboxylating) EC 1.1.1.40)
catalyzes the incorporation of proton from medium water into pyruvate present
either as the initial substrate or as the enzyme-bound product of malate
decarboxylation. In the later reaction a single proton is incorporated into the
methyl group of pyruvate. The pyruvate-medium proton exchange reaction requires
Mg2+, NADPH and CO2-HCO3- as cofactors. The apparent Michaelis constants of
pyruvate, NADPH and CO2-HCO3- are 4.8 mM, 2 microM and approx. 9 microM,
respectively. The experimentally determined incorporation of 2.5 tritium atoms
from tritiated water into pyruvate indicates that all three methyl protons of
this compound are stereochemically equivalent in the exchange reaction. These
results are consistent with the postulated kinetic mechanism for the malate
reaction (Hsu, R.Y., Lardy, H.A. and Cleland, W.W. (1967) J. Biol. Chem. 242,
5315--5322), which predicts the formation of an enolpyruvate intermediate during
the reaction. The rate of malic enzyme-catalyzed detritiation of beta-tritiated
pyruvate is unaffected by modification of an essential protein thiol group with
5,5'-dithiobis(2-nitrobenzoic acid) or KCN. Moreover, the native- and
thiol-modified enzymes also catalyze the detritiation of beta-tritiated
bromopyruvate at slower rates.
- Language of Publication
- English
- Unique Identifier
- 82160971
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- MeSH Heading (Major)
- Liver|*EN; Malate Dehydrogenase|*ME
- MeSH Heading
- Affinity Labels|PD; Animal; Dithionitrobenzoic Acid|PD; Kinetics; Pigeons;
Potassium Cyanide|PD; Pyruvates|PD; Support, U.S. Gov't, P.H.S.;
Thiocyanates|PD; Tritium
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3002
- Country of Publication
- NETHERLANDS
Record 90 from database: MEDLINE
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- Title
- Hepatic lipogenesis and mobilization of peripheral fats in the formation of
alcoholic fatty liver.
- Author
- Muramatsu M; Kuriyama K; Yuki T; Ohkuma S
- Address
-
- Source
- Jpn J Pharmacol, 1981 Dec, 31:6, 931-40
- Abstract
- Biochemical mechanisms underlying the development of alcoholic fatty liver
was investigated. Acute ethanol (EtOH) administration for 3 days by an
inhalation method, and continuous EtOH treatments by feeding with liquid diet or
drinking water containing EtOH induced a significant increase of hepatic
triglycerides (TG). A small but significant increase of TG was also observed in
the blood serum. Although hepatic acetyl CoA carboxylase activity, measured in
the presence and absence of citrate, was not altered by either acute or chronic
EtOH administrations, fatty acid synthetase and malic enzyme activities in the
liver were increased by continuous EtOH administration, but not in the acutely
EtOH-treated animals. The incorporations of [14C]palmitate and [14C]acetate into
hepatic RG were also increased significantly in animals treated continuously
with EtOH. The lipoprotein lipase activity in adipose tissues was activated by
both acute and continuous EtOH treatments, whereas lipase activity in adipose
tissues and the epinephrine-stimulated and cyclic AMP-mediated release of free
fatty acid (FFA) from this tissue were not altered by these treatments. These
results indicate that acute alcoholic fatty liver is caused mostly by the
increased mobilization of FFA from peripheral adipose tissues via the activation
of lipoprotein lipase, whereas alcoholic fatty liver induced by continuous EtOH
administration involves the increased synthesis of FFA due to the activation of
fatty acid synthetase and malic enzyme in the liver in addition to the increased
mobilization of peripheral FFA.
- Language of Publication
- English
- Unique Identifier
- 82146371
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- MeSH Heading (Major)
- Fatty Liver, Alcoholic|*ET; Lipid Mobilization|*; Lipids|*BI; Liver|*ME
- MeSH Heading
- Acetyl-CoA Carboxylase|AN; Adipose Tissue|ME; Animal; Fatty Acid Synthetase
Complex|AN; Fatty Acids, Nonesterified|ME; Male; Mice; Mice, Inbred Strains;
Palmitates|ME; Triglycerides|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-5198
- Country of Publication
- JAPAN
Record 91 from database: MEDLINE
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- Title
- Effects of ethanol and acetic acid on the transport of malic acid and
glucose in the yeast Schizosaccharomyces pombe: implications in wine
deacidification.
- Author
- Sousa MJ; Mota M; Leão C
- Address
- Department of Biology, University of Minho, Braga, Portugal.
- Source
- FEMS Microbiol Lett, 1995 Feb, 126:2, 197-202
- Abstract
- Ethanol and acetic acid, at concentrations which may occur during
wine-making, inhibited the transport of L-malic acid in Schizosaccharomyces
pombe. The inhibition was non-competitive, the decrease of the maximum initial
velocity following exponential kinetics. Glucose transport was not significantly
affected either by ethanol (up to 13%, w/v) or by acetic acid (up to 1.5%, w/v).
The uptake of labelled acetic acid followed simple diffusion kinetics,
indicating that a carrier was not involved in its transport. Therefore, the
undissociated acid appears to be the only form that enters the cells and is
probably responsible for the toxic effects. Accordingly, deacidification by Ss.
pombe during wine fermentation should take place before, rather than after, the
main alcoholic fermentation by Saccharomyces cerevisiae.
- Language of Publication
- English
- Unique Identifier
- 95220648
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full text for this document
- MeSH Heading (Major)
- Glucose|*ME; Malates|*ME; Schizosaccharomyces|*ME
- MeSH Heading
- Acetic Acids|PD; Biological Transport|DE; Ethanol|PD; Fermentation; Support,
Non-U.S. Gov't; Wine
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0378-1097
- Country of Publication
- NETHERLANDS
Record 92 from database: MEDLINE
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- Title
- Effects of insulin and fructose on transcriptional and post-transcriptional
regulation of malic enzyme synthesis in diabetic rat liver.
- Author
- Katsurada A; Iritani N; Fukuda H; Matsumura Y; Noguchi T; Tanaka T
- Address
- Tezukayama Gakuin College, Osaka, Japan.
- Source
- Biochim Biophys Acta, 1989 Jul, 1004:1, 103-7
- Abstract
- Insulin action on regulation of hepatic malic enzyme has been investigated
in comparison with fructose, using streptozotocin-induced diabetic rats.
Insulin-treatment caused a 2.8-fold increase in the transcriptional rate of
malic enzyme (EC 1.1.1.40) after 8 h, and a 5-fold increase in the mRNA
concentration of the liver. In Northern blot analysis, we demonstrated that
after insulin treatment, the nuclear mRNA of malic enzyme tended to increase
more rapidly than the total cellular mRNA. Therefore, it is suggested that the
nuclear mRNA was primarily increased by insulin. The insulin-dependent increase
of malic enzyme mRNA was blocked by cycloheximide, suggesting that synthesis of
a peptide is required. On the other hand, by feeding a high-fructose diet to
diabetic rats, the malic enzyme mRNA concentration was considerably increased,
though with a delayed peaking in comparison with the insulin-treated animals,
whereas the transcriptional rate was not significantly increased. Dietary
fructose may stabilize the transcripts. Fructose increased the enzyme level far
less than the mRNA level. These results suggest that insulin is required in both
the translational and transcriptional regulation of malic enzyme.
- Language of Publication
- English
- Unique Identifier
- 89302986
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full text for this document
- MeSH Heading (Major)
- Diabetes Mellitus, Experimental|*EN; Fructose|*PD; Insulin|*PD; Malate
Dehydrogenase|*BI/GE; Protein Processing, Post-Translational|*/DE;
Transcription, Genetic|*/DE
- MeSH Heading
- Animal; Blotting, Northern; Dietary Carbohydrates|PD; Enzyme Induction|DE;
Gene Expression Regulation|DE; Male; Nucleic Acid Hybridization; Rats; Rats,
Inbred Strains; RNA, Messenger|DE
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3002
- Country of Publication
- NETHERLANDS
Record 93 from database: MEDLINE
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- Title
- Low- and high-affinity transport systems for citric acid in the yeast
Candida utilis.
- Author
- Cássio F; Leáo C
- Address
- Laboratory of Biology, University of Minho, Braga, Portugal.
- Source
- Appl Environ Microbiol, 1991 Dec, 57:12, 3623-8
- Abstract
- Citric acid-grown cells of the yeast Candida utilis induced two transport
systems for citric acid, presumably a proton symport and a facilitated diffusion
system for the charged and the undissociated forms of the acid, respectively.
Both systems could be observed simultaneously when the transport was measured at
25 degrees C with labelled citric acid at pH 3.5 with the following kinetic
parameters: for the low-affinity system, Vmax, 1.14 nmol of undissociated citric
acid s-1 mg (dry weight) of cells-1, and Km, 0.59 mM undissociated acid; for the
high-affinity system, Vmax, 0.38 nmol of citrate s-1 mg (dry weight) of cells-1,
and Km, 0.056 mM citrate. At high pH values (above 5.0), the low-affinity system
was absent or not measurable. The two transport systems exhibited different
substrate specificities. Isocitric acid was a competitive inhibitor of citric
acid for the high-affinity system, suggesting that these tricarboxylic acids
used the same transport system, while aconitic, tricarballylic, trimesic, and
hemimellitic acids were not competitive inhibitors. With respect to the
low-affinity system, isocitric acid, L-lactic acid, and L-malic acid were
competitive inhibitors, suggesting that all of these mono-, di-, and
tricarboxylic acids used the same low-affinity transport system. The two
transport systems were repressed by glucose, and as a consequence diauxic growth
was observed. Both systems were inducible, and not only citric acid but also
lactic acid and malic acid may induce those transport systems. The induction of
both systems was not dependent on the relative concentration of the anionic
form(s) and of undissociated citric acid in the culture medium.(ABSTRACT
TRUNCATED AT 250 WORDS)
- Language of Publication
- English
- Unique Identifier
- 92152862
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full text for this document
- MeSH Heading (Major)
- Candida|GD/*ME; Citrates|*ME
- MeSH Heading
- Biological Transport; Cell Membrane|ME; Diffusion; Hydrogen-Ion
Concentration; Kinetics; Protons; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0099-2240
- Country of Publication
- UNITED STATES
Record 94 from database: MEDLINE
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- Title
- Nutritional and hormonal regulation of mRNA levels of lipogenic enzymes in
primary cultures of rat hepatocytes.
- Author
- Fukuda H; Katsurada A; Iritani N
- Address
- Tezukayama Gakuin College, Osaka.
- Source
- J Biochem (Tokyo), 1992 Jan, 111:1, 25-30
- Abstract
- The effects of nutrients and hormones on the mRNA levels of acetyl-CoA
carboxylase, fatty acid synthase, malic enzyme, and glucose 6-phosphate
dehydrogenase were examined in primary cultures of rat hepatocytes during the
process of induction. The addition of both glucose and insulin to the culture
medium markedly enhanced the lipogenic enzyme mRNA induction due to either of
them, in 16 h. Fructose or glycerol proved to be an effective substitute for
glucose, suggesting that glycolytic metabolites were involved in the mRNA
induction. It is remarkable that mRNA induction of acetyl-CoA carboxylase was
the most sensitive to glucose and also to insulin among the lipogenic enzymes.
Polyunsaturated fatty acids markedly reduced the mRNA induction of lipogenic
enzymes. Dexamethasone enhanced all the lipogenic enzyme mRNA induction by
insulin. On the other hand, triiodothyronine addition greatly increased the mRNA
concentrations of lipogenic enzymes, but dexamethasone decreased rather than
increased the mRNA induction by triiodothyronine. The effects of insulin on the
induction of the lipogenic enzyme mRNAs were similar, but those of
triiodothyronine were not. Triiodothyronine markedly enhanced malic enzyme mRNA
induction by insulin with dexamethasone, and tended to enhance the induction of
the acetyl-CoA carboxylase and fatty acid synthase mRNAs, but not that of
glucose 6-phosphate dehydrogenase mRNA. It appeared that insulin and
triiodothyronine synergistically enhanced lipogenic enzyme mRNA induction by
glucose, but the mechanisms were different.
- Language of Publication
- English
- Unique Identifier
- 92299648
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full text for this document
- MeSH Heading (Major)
- Fatty Acids|*BI; Glucose|*PD; Insulin|*PD; Liver|CY/EN/*ME; RNA,
Messenger|*GE/ME
- MeSH Heading
- Acetyl-CoA Carboxylase|BI/GE; Animal; Cells, Cultured; Enzyme Induction;
Fatty Acid Synthetase Complex|BI/GE; Glucosephosphate Dehydrogenase|BI/GE;
Malate Dehydrogenase|BI/GE; Male; Rats; Rats, Inbred Strains; Support, Non-U.S.
Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-924X
- Country of Publication
- JAPAN
Record 95 from database: MEDLINE
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full text for this document
- Title
- Identification of Asp258 as the metal coordinate of pigeon liver malic
enzyme by site-specific mutagenesis.
- Author
- Wei CH; Chou WY; Chang GG
- Address
- Graduate Institutes of Life Sciences and Biochemistry, National Defense
Medical Center, Taipei, Taiwan, Republic of China.
- Source
- Biochemistry, 1995 Jun, 34:24, 7949-54
- Abstract
- Pigeon liver malic enzyme was inactivated by ferrous sulfate in the presence
of ascorbate. Manganese and some other divalent metal ions provided complete
protection of the enzyme against the Fe(2+)-induced inactivation. The
inactivated enzyme was subsequently cleaved by the Fe(2+)-ascorbate system at
Asp258-Ile259, which was presumably the Mn(2+)-binding site of the enzyme [Wei,
C. H., Chou, W. Y., Huang, S. M., Lin, C. C., & Chang, G. G. (1994)
Biochemistry 33, 7793-7936]. For identification of Asp258 as the putative
metal-binding site of the enzyme, we prepared four mutant enzymes substituted at
Asp258 with glutamate (D258E), asparagine (D258N), lysine (D258K), or alanine
(D258A), respectively. These mutant proteins were recombinantly expressed in a
bacterial expression system (pET-15b) with a stretch of histidine residues
attached at the N-terminus and were successfully purified to apparent
homogeneity by a single Ni-chelated affinity column. Among the four mutants,
only D258E possessed 0.8% residual activity after purification; all other
purified mutants had < 0.0001% residual activity in catalyzing the oxidative
decarboxylation of L-malate. The D258E mutant was susceptible to inactivation by
the Fe(2+)-ascorbate system, albeit with much slower inactivation rate, and was
protected by the Mn2+ to a lesser extent as compared to the wild-type enzyme.
None of the mutants were cleaved by the Fe(2+)-ascorbate system under conditions
that cleaved the natural or wild-type enzyme at Asp258.(ABSTRACT TRUNCATED AT
250 WORDS)
- Language of Publication
- English
- Unique Identifier
- 95315182
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full text for this document
- MeSH Heading (Major)
- Aspartic Acid|GE/*ME; Malate Dehydrogenase|GE/IP/*ME; Metalloproteins|GE/*ME
- MeSH Heading
- Amino Acids|GE/ME; Animal; Ascorbic Acid|PD; Base Sequence; Binding
Sites|GE; Comparative Study; Ferrous Compounds|PD; Kinetics; Liver|EN;
Magnesium|ME; Manganese|ME; Molecular Sequence Data; Mutagenesis, Site-Directed;
Pigeons; Structure-Activity Relationship; Support, Non-U.S. Gov't
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2960
- Country of Publication
- UNITED STATES
Record 96 from database: MEDLINE
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full text for this document
- Title
- Effects of aging on contributions of dietary fat and triiodothyronine
treatment to lipogenic enzyme induction.
- Author
- Fukuda H; Katsurada A; Iritani N
- Address
-
- Source
- Biochim Biophys Acta, 1987 Sep, 921:1, 43-9
- Abstract
- Although lipogenic enzyme inductions are reduced by fat feeding, this
reduction decreases with aging and is particularly detectable in the case of
acetyl-CoA carboxylase and fatty acid synthetase activities. On the other hand,
the fat-dependent reductions of malic enzyme and acetyl-CoA carboxylase were
consistently relieved by triiodothyronine (T3) treatment. The effects of T3
treatment on these enzyme inductions were greater in 10-month-old rats than in
1-month-old rats, while the carbohydrate-dependent induction and the
fat-dependent reduction of the enzymes decreased with aging. In these animals,
alterations in malic enzyme mRNA translational activities were roughly in
parallel to the enzyme activities. Therefore, the age-dependent alterations in
effects of T3 treatment and fat on malic enzyme induction do not appear to occur
in post-translation.
- Language of Publication
- English
- Unique Identifier
- 87299760
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full text for this document
- MeSH Heading (Major)
- Aging|*; Dietary Fats|*PD; Lipids|*BI; Triiodothyronine|*PD
- MeSH Heading
- Acetyl-CoA Carboxylase|BI; Adipose Tissue|AN; Animal; Body Weight; Enzyme
Induction; Fatty Acid Synthetase Complex|BI; Glucosephosphate Dehydrogenase|BI;
Liver|EN; Malate Dehydrogenase|BI; Male; Rats; Rats, Inbred Strains;
Triglycerides|ME
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-3002
- Country of Publication
- NETHERLANDS
Record 97 from database: MEDLINE
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full text for this document
- Title
- Cloning of cDNA sequences for murine malic enzyme and the identification of
aberrantly large malic enzyme mRNA in MOD-1 null mice.
- Author
- Sul HS; Wise LS; Brown ML; Rubin CS
- Address
-
- Source
- J Biol Chem, 1984 Jan, 259:1, 555-9
- Abstract
- Polysomes containing cytosolic malic enzyme mRNA and malic enzyme nascent
chains were complexed with specific antibodies and purified by chromatography on
protein A-Sepharose. When poly(A+) mRNA derived from the immunoselected
polysomes was translated in vitro, full length malic enzyme (subunit Mr =
58,000) accounted for a significant fraction (approximately 20%) of the
polypeptides synthesized. Double-stranded cDNA, synthesized using partially
purified malic enzyme mRNA as a template, was inserted into pBR 322 and cloned.
Twenty-five candidate malic enzyme cDNA clones were identified by differential
hybridization. Four clones were studied further and each of these was shown to
have malic enzyme cDNA sequences by hybrid-selected translation and specific
immunoprecipitation. Plasmid pME1, which contains a 1400-base pair insert,
hybridized to two mouse liver malic enzyme mRNAs with lengths of 2300 and 3500
bases. Similar analyses were performed on liver mRNAs isolated from MOD-1 mutant
mice which lack cytosolic malic enzyme activity. These Northern blots disclosed
a pair of aberrantly large malic enzyme mRNAs with lengths of 2800 and 4000
bases. Furthermore, anti-malic enzyme antibodies exclusively precipitated a
polypeptide translation product with a Mr of 77,000 when MOD-1 mRNA was used to
direct in vitro protein synthesis. Thus, it is possible that MOD-1 malic enzyme
mRNA contains an additional polypeptide coding sequence. The translation of such
a sequence might disrupt enzyme function and/or markedly decrease enzyme
stability. The malic enzyme cDNA probe was also employed to demonstrate that the
induction of malic enzyme in the livers of previously starved mice that were fed
a high carbohydrate, fat-free diet was controlled pretranslationally by a
parallel modulation of the malic enzyme mRNA concentration.
- Language of Publication
- English
- Unique Identifier
- 84161965
Order
full text for this document
- MeSH Heading (Major)
- Cloning, Molecular|*; DNA|*ME; Malate Dehydrogenase|*GE; RNA, Messenger|*AN
- MeSH Heading
- Animal; Base Sequence; Liver|EN; Mice; Mice, Mutant Strains; Nucleic Acid
Hybridization; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0021-9258
- Country of Publication
- UNITED STATES
Record 98 from database: MEDLINE
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full text for this document
- Title
- Regulation of hepatic malic enzyme by perfluorodecanoic acid.
- Author
- Kelling CK; Van Rafelghem MJ; Drake RL; Menahan LA; Peterson RE
- Address
- School of Pharmacy, University of Wisconsin, Madison 53706.
- Source
- J Biochem Toxicol, 1986 Sep, 1:3, 23-37
- Abstract
- Perfluorodecanoic acid (PFDA) administration to adult male rats increased
both the activity of hepatic malic enzyme and liver weight in a dose-dependent
manner. Hepatomegaly and augmented activity of malic enzyme in liver were
apparent within one day following PFDA administration and reached a plateau by
three days posttreatment. Malic enzyme quantity per liver in PFDA-treated rats
was elevated within one day following dosing and increased continually
throughout five days posttreatment. Administration of PFDA to rats in the fed
state also led to an increase in the specific activity of hepatic malic enzyme
that peaked at three days following dosing. When compared to the fed condition,
rats fasted for 48 hours had a decrease in both relative liver weight and the
quantity of supernatant protein per liver. The total activity (U/liver) and
specific activity of malic enzyme in the liver were also reduced in the fasted
state. During the 24 hours after treatment in rats fasted for 48 hours, the body
weight as well as the absolute and relative liver weight of animals receiving
vehicle declined continuously in the absence of feed. Following the
administration of PFDA to fasted rats, body weight was maintained until eight
hours posttreatment but then declined at a rate similar to that found with the
vehicle-treated group. Absolute and relative liver weight in PFDA-treated rats
were increased significantly at eight hours posttreatment when compared to those
receiving vehicle, and this increment was maintained throughout the rest of the
24 hours following dosing. While the activity and enzyme content of hepatic
malic enzyme decreased in the vehicle-treated group, administration of PFDA to
rats fasted for 48 hours prevented their decline. The specific activity of
hepatic malic enzyme in 48 hours fasted rats receiving PFDA was also elevated
significantly at 16 hours posttreatment. Thus, the administration of PFDA to the
adult male rat in both the fed and fasted nutritional states was found to
regulate hepatic malic enzyme by not only increasing enzyme quantity but also by
augmenting the specific activity, (ie, catalytic state) of the enzyme.
- Language of Publication
- English
- Unique Identifier
- 90156341
Order
full text for this document
- MeSH Heading (Major)
- Decanoic Acids|*PD; Fluorocarbons|*PD; Liver|DE/*EN/ME; Malate
Dehydrogenase|*ME
- MeSH Heading
- Animal; Body Weight|DE; Dose-Response Relationship, Drug; Enzyme
Induction|DE; Male; Organ Weight|DE; Rats; Rats, Inbred Strains; Support, U.S.
Gov't, Non-P.H.S.; Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0887-2082
- Country of Publication
- UNITED STATES
Record 99 from database: MEDLINE
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full text for this document
- Title
- AP-1 and T3RE cis elements operate as a functional unit in the
transcriptional control of the human malic enzyme gene.
- Author
- González-Manchón C; Ayuso MS; Parrilla R
- Address
- Department of Pathophysiology and Human Molecular Genetics, Centro de
Investigaciones Biológicas (CSIC), Velázquez 144, 28006, Madrid, Spain.
- Source
- Gene, 1999 Jan 8, 226:1, 111-9
- Abstract
- The human malic enzyme (hME) promoter contains an inverted palindromic (IP4)
3,5,3'-triiodo-thyronine (T3) response element (T3RE) 15bp downstream from an
activating protein-1 (AP-1) site. The purpose of this study was to analyze the
functional relationship between both cis-acting elements. The following
observations indicate that these two elements operate as a functional unit in
controlling the human ME gene:T3 failed to stimulate transcription above the
basal levels in cells overexpressing either TRb or TRb/retinoid acid receptor
(RXR), indicating that TRbeta acts primarily as a transcriptional repressor in
the context of the hME. Moreover, the finding of a repressive effect of TRbeta
without DNA binding suggests the existence of both DNA-dependent and independent
mechanisms of TRbeta-induced repression of transcription.
- Language of Publication
- English
- Unique Identifier
- 99107775
Order
full text for this document
- MeSH Heading (Major)
- Malate Dehydrogenase|*GE/ME; Receptors, Thyroid Hormone|DE/GE/*ME;
Regulatory Sequences, Nucleic Acid|*; Response Elements|*PH; Transcription
Factor AP-1|GE/*ME
- MeSH Heading
- DNA|ME; DNA-Binding Proteins|GE/ME; Gene Expression Regulation; Human;
Mutation; Promoter Regions (Genetics); Receptors, Retinoic Acid|GE/ME; Support,
Non-U.S. Gov't; Transcription Factors|GE/ME; Transcription, Genetic;
Triiodothyronine|ME/PD
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0378-1119
- Country of Publication
- NETHERLANDS
- CAS Registry/EC Number
- EC 1.1.1.37 (Malate Dehydrogenase); 0 (retinoid X receptor); 0 (DNA-Binding
Proteins); 0 (Receptors, Retinoic Acid); 0 (Receptors, Thyroid Hormone); 0
(Transcription Factor AP-1); 0 (Transcription Factors); 6893-02-3
(Triiodothyronine); 9007-49-2 (DNA)
Record 100 from database: MEDLINE
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full text for this document
- Title
- Determination of dissociation constants for enzyme-reactant complexes for
NAD-malic enzyme by modulation of the thiol inactivation rate.
- Author
- Kiick DM; Allen BL; Rao JG; Harris BG; Cook PF
- Address
-
- Source
- Biochemistry, 1984 Nov, 23:23, 5454-9
- Abstract
- Incubation of NAD-malic enzyme from Ascaris suum with the sulfhydryl
reagents N-ethylmaleimide (NEM), 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), or
4,4'-dithiodipyridine (4-PDS) results in rapid and complete loss of malate
oxidative decarboxylase and pyruvate reductive carboxylase activities. With
DTNB, this loss of activity occurs concomitantly with the modification of about
1 thiol group per subunit. The majority of the activity is lost when 0.5 thiol
per subunit is modified, indicative of possible half-site reactivity with DTNB.
Complete restoration of activity follows addition of dithiothreitol to enzyme
inactivated by DTNB and 4-PDS but not with NEM. With the DTNB-inactivated
enzyme, replacement of the thionitrobenzoate moiety with cyanide restores
activity. The presence of a divalent metal ion (Mg2+ or Mn2+) results in
enhancement of the inactivation rate with all sulfhydryl reagents. However,
malate alone or competitors of malate provide protection which is more effective
in the presence of Mg2+, while NAD provides only about 25% protection. Thus, the
Ascaris suum NAD-malic enzyme has a thiol group probably located in or near the
malate binding site, which is not essential for enzyme activity. The changes in
the rate of inactivation in the presence of reactants were used to determine the
dissociation constants for enzyme-reactant complexes. These data suggest that
all three possible binary and all three possible ternary complexes form. The
binding of malate to free enzyme exhibits negative cooperativity, which is
eliminated by the presence of either NAD or Mg2+.(ABSTRACT TRUNCATED AT 250
WORDS)
- Language of Publication
- English
- Unique Identifier
- 85072841
Order
full text for this document
- MeSH Heading (Major)
- Ascaris|*EN; Malate Dehydrogenase|*AI/ME; NAD|*ME/PD; Sulfhydryl
Compounds|*; Sulfhydryl Reagents|*PD
- MeSH Heading
- Animal; Dithionitrobenzoic Acid|PD; Ethylmaleimide|PD; Hydrogen-Ion
Concentration; Kinetics; Magnesium|PD; Malates|PD; Manganese|PD; Pyridines|PD;
Support, U.S. Gov't, P.H.S.
- Publication Type
- JOURNAL ARTICLE
- ISSN
- 0006-2960
- Country of Publication
- UNITED STATES
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