Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

1. Both Isotricha intestinalis and I. prostoma possess microbody-like organelles, with a highly granular appearance. 2. These organelles, which are sedimentable at 10(5) g-min, bear no morphological similarity to mitochondria, but are enzymatically similar to organelles possessed by certain other anaerobic protozoa and termed hydrogenosomes. 3. The hydrogenosomes isolated from a preparation of mixed isotrichs bear a closer similarity to those isolated from the other rumen holotrich. Dasytricha ruminantium, than those recently identified in a mixed entodiniomorph preparation, or the trichomonads, in that the enzyme malate dehydrogenase (decarboxylating) is non-sedimentable and phosphoacetyl transferase together with acetate kinase are involved in the transformation of acetyl CoA to acetate. 4. The results enable a scheme of acetate, CO2 and H2 formation from carbohydrates to be proposed and extends the number of protozoa known to possess this organelle.
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PMID:Hydrogenosomes in a mixed isolate of Isotricha prostoma and Isotricha intestinalis from ovine rumen contents. 640 85

Glycogen content, glucose consumption and the production of metabolic end products by Calicophoron ijimai were determined under aerobic and anaerobic conditions. The major end products of fermentation were identified as lactic, acetic, propionic, isobutyric and alpha-methylbutyric acids, propionic acid predominating. The activities and properties of some of the enzymes of carbohydrate metabolism were determined. The worms showed high phosphoenolpyruvate carboxykinase, malate dehydrogenase and malate dehydrogenase (decarboxylating) but relatively low pyruvate kinase and very low lactate dehydrogenase activities. The pH optima, coenzyme, cofactor and ionic requirements of the enzymes were similar to those of other helminths. Malate dehydrogenase had an 8-fold greater affinity for oxaloacetate than malate, and was about 14 times more active for oxaloacetate reduction than malate oxidation. Phosphoenolpyruvate carboxykinase was 2.4 times more active and had a 2-fold greater affinity for phosphoenolpyruvate and dinucleotide than pyruvate kinase. The low activities of lactate dehydrogenase and pyruvate kinase but high activities of malate dehydrogenase and phosphoenolpyruvate carboxykinase suggest that anaerobic carbohydrate catabolism follows the fumarate reductase pathway.
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PMID:Fermentation and the properties of some enzymes of carbohydrate metabolism in the trematode Calicophoron ijimai. 651 86

Chicks were given biotin-deficient diets containing either suboptimal (low) or supraoptimal (high) concentrations of protein from 1-d-old until they were used during their fourth week of life. The low-protein diet predisposed chicks to develop fatty liver and kidney syndrome and the high-protein diet to develop classical biotin deficiency signs. Two other groups, as controls, received biotin-supplemented rations. Low dietary protein increased lipogenesis by isolated hepatocytes but had little effect on gluconeogenesis compared to high dietary protein. Low dietary protein decreased activities of hepatic isocitrate dehydrogenase (EC 1.1.1.42), fructose-1,6-bisphosphatase (EC 3.1.3.11) and glucose-6-phosphatase (EC 3.1.3.9; GP) and increased activities of fatty acid synthase (FAS), citrate cleavage enzyme (EC 4.1.3.8; CCE) and malate dehydrogenase (decarboxylating) (EC 1.1.1.39). When biotin deficiency was superimposed, the rate of lipogenesis by isolated hepatocytes (from fed birds) was decreased. Gluconeogenesis from lactate and glycerol was also depressed. Activity of GP was further decreased by biotin deficiency on the low-protein regimen and FAS and CCE were further increased. PK activity was increased by biotin deficiency.
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PMID:The effect of biotin deficiency and dietary protein content on lipogenesis, gluconeogenesis and related enzyme activities in chick liver. 661 62

The relative mobilities of six enzymes from the trophozoites of five axenically-cultured isolates of Giardia from human, cat, and guinea pig hosts were compared by starch and polyacrylamide gel electrophoresis. The six enzymes compared were malate dehydrogenase (NAD+) (MDH) (EC 1.1.1.37), malate dehydrogenase (decarboxylating) (ME) (EC 1.1.1.40), hexokinase (EC 2.7.1.1), 6-phosphogluconate dehydrogenase (EC 1.1.1.44), glucose-6-phosphate dehydrogenase (G6P) (EC 1.1.1.49), and alpha-glycerophosphate dehydrogenase (EC 1.1.1.8). The latter three enzymes have not been previously reported in Giardia. On the basis of zymogram patterns, the five Giardia isolates were divided into three zymodemes. Zymodeme I comprised human-1/England, human-1/Bethesda, and cat-1/Portland, Zymodeme II the guinea pig-1/Portland isolate, and Zymodeme III the human-1/Portland isolate. These zymodemes were further substantiated when several physical and kinetic properties of three of the enzymes, MDH, ME, and G6P, were examined. Our results, in which Giardia isolated from different mammalian hosts share multiple isoenzymes, question the validity of the practice of assigning Giardia species names on the basis of the animal host from which the protozoan was obtained.
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PMID:A comparison of isozymes of five axenic Giardia isolates. 667 61

The molecular size of seven Trypanosoma cruzi enzymes, chosen because of their frequent use in studying trypanosome populations, has been found to be similar to that of their mammalian equivalents. Malic enzyme (NADP-dependent malate dehydrogenase, decarboxylating, EC 1.1.1.40) from T. cruzi has an apparent molecular size of only half that of the mammalian enzyme. The probable subunit structure of these T. cruzi enzymes has been deduced from the molecular weights by comparison with mammalian data. The results are compatible with recent interpretations of isozyme data implying the existence of genetic diploidy in trypanosomes.
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PMID:Molecular size of enzymes in Trypanosoma cruzi considered in relationship to the genetic interpretation of isozyme patterns. 675 48

This study has investigated the feasibility of calculating the cytoplasmic free [NADP+]/[NADPH] ratio in rat brain. The time course of the change in the substrate ratios of the malate dehydrogenase (decarboxylating) [E.C. 1.1.1.40], NADP+-isocitrate dehydrogenase (decarboxylating) [E.C. 1.1.1.42] and 6-phosphogluconate dehydrogenase (decarboxylating) [E.C. 1.1.1.44] reactions was followed for up to 10 min after a single, unmodified electroconvulsive seizure. From the results it has been concluded that during periods of low flux, the direction and magnitude of the change in the cytoplasmic free [NADP+]/[NADPH] ratio can, in fact, be reasonably determined even though there is some uncertainty in the absolute value of the ratio itself. It is recommended that reliance not be placed on a single enzyme system but that one or both of the other systems also be observed under a given experimental condition to increase confidence in the determination. The results also demonstrate that seizure and anoxia have a far lesser effect on the cytoplasmic free [NADP+]/[NADPH] ratio than on the free [NAD+]/[NADH] ratio in the same compartment. These results suggest that the pathways using the nicotinamide-adenine dinucleotide phosphate system are relatively protected from the rapid fluctuations that seizure and anoxia can produce.
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PMID:The calculation of the cytoplasmic free [NADP+]/[NADPH] ratio in brain: effect of electroconvulsive seizure. 679 9

This paper reports for the first time the presence in the anaerobic rumen ciliate Dasytricha ruminantium (Schuberg) of microbody-like organelles, about 0.5 micrometer diameter, with a granular matrix and an equilibrium density of approx. 1.18 g/ml. These organelles can be isolated in a fraction sedimented at 10(5) g-min that contains 67% of the total pyruvate synthase (EC 1.2.7.1), 66% of the hydrogenase (EC 1.18.3.1) and 20% of the lactate dehydrogenase (EC 1.1.1.27). Thus in several respects this fraction is enzymically similar to those containing hydrogenosomes in some other parasitic anaerobic protozoa (the trichomonads). However, in contrast with the hydrogenosomes of trichomonads, the oxygen-tolerant enzyme malate dehydrogenase (decarboxylating) (EC 1.1.1.40) is not particulate, but occurs only in the cytosol. These results enable the proposal of a scheme for the pathway of product formation (acetate, lactate, CO2 and H2) from carbohydrates.
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PMID:Hydrogenosomes in the rumen protozoon Dasytricha ruminantium Schuberg. 680 78

Adult H. microstoma mitochondria catalyzed a malate dehydrogenase, decarboxylating ("malic" enzyme) activity. This "malic" enzyme was found as a soluble component of the mitochondrion, was specific for NADP, and required a divalent cation with Mn++ ion yielding the greatest activity. The H. microstoma "malic" enzyme could fulfill the need for generating intramitochondrial reducing equivalents required for electron transport. The H. microstoma mitochondria also exhibited an NADPH:NAD transhydrogenation reaction. The electron transport system of this cestode was apparently specific for NADH both in terms of the rotenone-sensitive oxidase and fumarate reductase systems. Electron transport-associated NADPH oxidation was increased markedly with the addition of NAD to the system. Coupling of NADPH utilization to fumarate reduction, in the presence of NAD, was apparent under conditions of reduced oxygen tension. This was consistent with the presence of the NADPH:NAD transhydrogenase which catalyzed a transfer of reducing equivalents from NADPH to NAD, producing NADH for electron transport function. The data presented suggest that H. microstoma mitochondria can engage in an anaerobic, electron transport-associated production of succinate, and presumably concomitant phosphorylation. Malate may serve as the mitochondrial substrate supplying reducing equivalents for electron transport via the activity of the "malic" enzyme coupled to the NADPH:NAD transhydrogenase. In addition to the NADPH:NAD transhydrogenase activity, H. microstoma mitochondria catalyzed an NADH:NAD transhydrogenation.
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PMID:Mitochondrial malate dehydrogenase, decarboxylating ("malic" enzyme) and transhydrogenase activities of adult Hymenolepis microstoma (Cestoda). 707 55

The energy metabolism of the English E-CMO strain of contagious equine metritis bacterium was studied in whole cells and cell extracts. This bacterium appears to have an active Krebs cycle and probably obtains energy by oxidative phosphorylation since glycolysis and the hexose monophosphate pathways appear to be absent. These conclusions are based on the findings that [U-14C]glucose incorporation by this bacterium is below the level of detection, and that respiration is stimulated by Krebs cycle intermediates (i.e., malate, citrate, and succinate), but not by glucose, fructose, maltose, or sucrose. Furthermore, support comes from the fact that enzymes generally associated with the Krebs cycle and electron transport (i.e., malate dehydrogenase, succinate dehydrogenase, isocitrate dehydrogenase, fumarate hydratase, malate dehydrogenase [decarboxylating], cytochrome oxidase, superoxide dismutase, NADH dehydrogenase, and catalase) were detected. Those enzymes normally associated with glycolysis and the hexose monophosphate pathways (i.e., hexokinase, glucose 6-phosphate dehydrogenase, fructose biphosphate aldolase, glycerol 3-phosphate dehydrogenase, phosphoenolpyruvate carboxykinase, pyruvate kinase, phosphate acetyl transferase, acetate kinase, alcohol dehydrogenase, and lactate dehydrogenase) were below the level of detection.
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PMID:Energy metabolism of the contagious equine metritis bacterium. 708 71

Kinetic studies of the individual reaction of pig heart pyruvate dehydrogenase complex (pyruvate dehydrogenase (pyruvate:lipoamide oxidoreductase (decarboxylating and acceptor-acetylating), EC 1.2.4.1); dihydrolipoamide reductase(NAD+) (NADH:lipoamide oxidoreductase, EC 1.6.4.3); dihydrolipoamide acetyltransferase (acetyl-CoA:dihydrolipoamide S-acetyltransferase, EC 2.3.1.12)), citrate synthase (citrate oxaloacetate-lyase (pro-3S-CH2COO- leads to acetyl-CoA), EC 4.1.3.7) and the pyruvate dehydrogenase complex-citrate synthase coupled system show that the KmCoA value of pyruvate dehydrogenase complex and KmCoASAc value of citrate synthase decrease in the coupled system when compared to those in the individual enzyme reactions. The explanation for this interaction may be an association between the two enzymes. When it was centrifuged with 150 000 x g for 140 min, 30% of the citrate synthase sedimented in the presence of the pyruvate dehydrogenase complex, while no sedimentation was observed in the absence of the pyruvate dehydrogenase complex. Sedimentation of cytoplasmic malate dehydrogenase, phosphotransacetylase, hemoglobin and Blue albumin were negligible under the same condition. In gel chromatography experiments a significant peak of citrate synthase activity co-migrated with the pyruvate dehydrogenase complex peak. This observation also suggests the possible association of two enzymes.
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PMID:Interaction between the pyruvate dehydrogenase complex and citrate synthase. 721 36


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