Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.37 (malate dehydrogenase)
 4,591 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activities of the eight citric acid-cycle enzymes of rat bone-marrow cells were determined along with several other mitochondrial and non-mitochondrial enzymes. Four of the citric acid-cycle enzymes (aconitase, succinyl-CoA thiokinase, alpha-oxoglutarate dehydrogenase and succinate dehydrogenase) have closely similar low activities; two [isocitrate dehydrogenase (NAD) and citrate synthase] have intermediate activities; the remaining two (malate dehydrogenase and fumarase) have high activities. The other enzymes surveyed also exhibited a spread of three orders of magnitude, the mitochondrial enzymes showing no less variation than the others.
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PMID:The activities of the citric acid-cycle enzymes in rat bone-marrow cells. 566 55

Acetate oxidation by sulphate was studied with desulfobacter postgatei. Cell extracts of the organism were found to contain high activities of the following enzymes: citrate synthase, aconitase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, fumarase, malate dehydrogenase and pyruvate synthase. It is concluded that acetate oxidation with sulphate in D. postgatei proceeds via the citric acid cycle with the synthesis of pyruvate from acetyl CoA and CO2 as an anaplerotic reaction. The apparent Ks for acetate oxidation by D. postgatei as determined in vivo was near 0.2 mM. The apparent Ks for acetate fermentation to methane and CO2 by methanosarcina barkeri was 3 mM. The significantly lower ks for acetate of the sulphate reducer explains why methane formation from acetate in natural habitats is apparently inhibited by sulphate.
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PMID:Dissimilatory sulphate reduction with acetate as electron donor. 612 36

Rat liver mitochondria, stored with the energy-linked functions preserved or in aging conditions, were used to assay the activity of various enzymes during five days. The preservation of energy-linked functions was monitored by the respiratory control coefficient. ATPase, cytochrome oxidase and NADH dehydrogenase showed increased activity when the energy-linked functions were preserved. In aging conditions, cytochrome oxidase, NADH dehydrogenase and ATPase showed decreased activity. The ATPase activity increased only when mitochondria were stored in the presence of inhibitors of the electron transport chain. The activity of NADH oxidase did not change, and succinate oxidase and succinate dehydrogenase showed a small decrease in their activity. The enzymes of the matrix, alpha-ketoglutarate dehydrogenase, malate dehydrogenase and aspartate aminotransferase showed little decrease in activity under either of the conditions of storage. The total protein content decreased slightly under both conditions of storage. These results show that the activity of the enzymes analysed was maintained at reasonable levels, when the energy-linked functions of isolated mitochondria were preserved.
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PMID:Studies on rat liver mitochondria: 4. Enzyme activities in mitochondria preserved at 0-4 degrees C. 646 13

Considerable variations were found in the in vitro effect of alloxan on mouse liver enzymes associated with the citric acid cycle. The following approximative alloxan concentrations induced 50% inhibition of enzyme activity: 10(-6)M for aconitase, 10(-4)M for NAD-linked isocitrate dehydrogenase, glutamate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinyl-CoA synthetase and fumarase, and 10(-3)M for citrate synthase and NADP-linked isocitrate dehydrogenase. Pyruvate dehydrogenase, succinate dehydrogenase and malate dehydrogenase were not inhibited by 10(-3)M alloxan. The inhibition of aconitase was competitive both when using mouse liver and purified porcine heart enzyme. The Ki values for the purified enzyme in the presence of 5 microM alloxan were 0.22 microM with citrate, 4.0 microM with cis-aconitate and 0.62 microM with isocitrate as substrate. The high sensitivity of aconitase for inhibition by alloxan probably plays a prominent role for the toxic effects of alloxan.
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PMID:Inhibition by alloxan of mitochondrial aconitase and other enzymes associated with the citric acid cycle. 651 May 22

Intraperitoneal injection of hydroxythiamine to rats (1 mmol per kg bw) resulted after 2-4 h in a more than 4-fold decrease in the activity of the oxoglutarate dehydrogenase complex, pyruvate dehydrogenase complex and NADP-dependent isocitrate dehydrogenase in adrenal mitochondria. Inhibition of hyaloplasmic transketolase, 6-phosphogluconate dehydrogenase and NADP-dependent malate dehydrogenase occurred later. Based on the correlation of the time course of enzymatic activity in the adrenals and the decreased concentration of 11-hydroxycorticosteroids in the blood the paramount role in the maintenance of the steroidogenesis among thiamine pyrophosphate-containing enzymes is assigned to the oxoglutarate dehydrogenase and pyruvate dehydrogenase complexes.
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PMID:[Enzyme activity of thiamine pyrophosphate in the rat after oxythiamine administration]. 664 96

The study of 165 rats exposed to 60-day hypokinesia demonstrated a decrease in the quantity of mitochondrial protein and a decline in the activity of mitochondrial forms of NADP-isocitrate dehydrogenase (NADP-ICDH) and NAD-malate dehydrogenase (NAD-MDH), as well as NAD-ICDH, succinate dehydrogenase (SDH) and alpha-ketoglutarate dehydrogenase (alpha-KGDH). The maximum decline in the protein content was seen on day 60, and in the enzyme activity on day 7. As the hypokinetic exposure continued, the activity of mitochondrial NAD-MDH and NADP-ICDH slightly increased. The NADP-MDH activity decreased only at later stages of hypokinesia. The changes in cytoplasmic NAD-MDH, NADP-ICDH and NADP-MDH were less expressed. On day 25 of the recovery period the activity of NAD-ICDH and NADP-ICDH was significantly higher than in the controls, that of mitochondrial NAD-MDH returned to the normal, and the activity of SDH and alpha-KGDH remained noticeably lowered.
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PMID:[Oxidative enzyme activity of the tricarboxylic acid cycle in rat skeletal muscles in hypokinesia]. 717 3

The activity of hexokinase, glucose-6-phosphate dehydrogenase, pyruvate dehydrogenase, isocytrate dehydrogenase, alpha-ketoglutarate dehydrogenase and the ATR content in the alveolar process and gingiva of dogs are established to decrease considerably in experimental cholestasis, induced by ligation of the common bile duct. Incorporation of tissue proteins into the Krebs cycle through the reverse NAD-dependent malate dehydrogenase reaction is a compensatory reaction favouring an increase of the ATP amount in the alveolar process.
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PMID:[Activity of carbohydrate metabolism enzyme activity in normal and pathologic parodontal tissues]. 721 Feb 21

In experiments with dogs stomatitis was simulated by ligation and section of the common biliary duct. On the third and fifth days in the oral cavity mucosa of the animals there occur essential changes in the energy producing reactions, which are controlled by pyruvate dehydrogenase NAD-dependent isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, NAD-dependent malate dehydrogenase. This is accompanied by a sharp decrease in the ATP amount.
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PMID:[Activities of certain krebs cycle dehydrogenases and the content of ATP in oral cavity mucosa in experimental stomatitis in dogs]. 725 20

The study on the effect of some antibiotics on the activity of pyruvate dehydrogenase (PDG) and dehydrogenases of the tricarboxylic acid cycle (TAC) in the cell extracts of Bac. polymyxa 153 producing polymyxin B showed that the level of the reaction of the individual enzymes to the effect of various antibiotics was different. Specific sensitivity to polymyxins M and B was found in succinate dehydrogenase and that to polymyxin B in malate dehydrogenase. The activity of the first components of the pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase complexes was completely suppressed not only by polymyxins M and B but also by novobiocin, ristomycin and nistatin. The activity of NADP-dependent isocitrate dehydrogenase was not suppressed by either of the antibiotics tested.
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PMID:[Antibiotic action on Bacillus polymyxa 153 enzymatic activity]. 735 5

We have developed and implemented a model that can predict the positional isotopomer distribution of various hepatic metabolites labeled with [U-13C3]lactate and/or [U-13C3]pyruvate for given relative flux rates through the citric acid cycle and gluconeogenesis reactions. Our model includes (i) isotopic exchange between alpha-ketoglutarate and glutamate, (ii) a reversible isocitrate dehydrogenase reaction, (iii) an active ATP-citrate lyase, and (iv) aspartate and malate shuttles with separate cytosolic and mitochondrial pools for oxaloacetate, malate, and fumarate. A parameter estimation routine fit the mass isotopomer distribution of selected metabolites measured by gas chromatography-mass spectrometry to the model predicted distributions. We fit measured mass isotopomer distributions of phosphoenolpyruvate, citrate, alpha-ketoglutarate, glutamate, and pyruvate isolated from fasted rat livers perfused with [U-13C3]lactate + [U-13C3]pyruvate. This fitting yielded rates which we express relative to that of pyruvate carboxylase: citric acid cycle represented by the irreversible alpha-ketoglutarate dehydrogenase = 0.32; citrate synthase = 0.64; reversal of isocitrate dehydrogenase = 0.52; citrate lyase = 0.33, aspartate shuttle = 0.24, and malate shuttle = 0.44. Rates calculated for the cytosolic and mitochondrial fumarate and malate dehydrogenase reactions are subject to uncertainties as indicated by identifiability analyses. Previous forms of our model that did not include pyruvate kinase, exchange of alpha-ketoglutarate with glutamate, reversibility of isocitrate dehydrogenase, and/or ATP-citrate lyase activity were not as successful at predicting our measured values. This model offers a general tool for studying the regulation of the citric acid cycle and gluconeogenesis and can be readily modified for any 13C-labeled lactate or pyruvate substrate.
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PMID:Modeling of liver citric acid cycle and gluconeogenesis based on 13C mass isotopomer distribution analysis of intermediates. 773 Mar 5


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