Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Crude extracts of both vegetative cells and glycerol-induced microcysts of Myxococcus xanthus contained the following enzyme activities: phosphofructokinase, phosphoglucoisomerase, fructose-1,6-diphosphatase, fructosediphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, phosphopyruvate carboxylase, citrate synthase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase, and uridine diphosphate glucose pyrophosphorylase. With the exception of isocitrate dehydrogenase, which was present at a fivefold higher concentration in microcysts, all activities in extracts from both types of cells were essentially equal. Hexokinase and pyruvate kinase could not be detected in extracts from either type of cell. Microcysts metabolized acetate at a lower rate than did vegetative cells. Most of this decrease was reflected in a substantial decrease in ability of microcysts to oxidize acetate to CO(2). In addition, microcysts and vegetative cells showed a different distribution of (14)C-label from incorporated acetate.
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PMID:Comparative intermediary metabolism of vegetative cells and microcysts of Myxococcus xanthus. 430 96

The freshwater murrel, Channa punctatus, was exposed to a sublethal concentration of mercuric chloride (3 micrograms/liter) for 120 days and the following effects were examined: changes in the levels of glucose and lactic acid in blood and of glycogen and lactic acid in liver and muscles; rate of absorption of glucose from the intestine; and changes in the activities of glucose-6-phosphatase (G-6-Pase), hexokinase, lactate dehydrogenase (LDH), pyruvate dehydrogenase (PDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), L-amino acid oxidase (AO), and xanthine oxidase (XO) in brain, gills, intestine, kidney, liver, and muscles. Mercury-treated fish were hypoglycemic and hypolactemic. The glycogen content of liver and muscles remained unaltered but the muscle lactic acid level decreased significantly. The rate of intestinal absorption of glucose was reduced significantly by exposure to mercury. G-6-Pase activity was decreased in all the tissues. Hexokinase activity also decreased in mercury-exposed fish but it was significant only in intestine, kidney, and liver. The activities of LDH, PDH, SDH, and MDH also were decreased significantly except LDH in brain and MDH in kidney where an insignificant decrease and an insignificant increase, respectively, were recorded. GDH and AO activities were elevated in most of the tissues except GDH in gills, and AO in gills and muscles where a decrease was observed. XO activity in brain, gills, and kidneys was significantly elevated, but no marked alteration was noted in other tissues.
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PMID:Effect of mercuric chloride on some biochemical and physiological parameters of the freshwater murrel, Channa punctatus. 608 7

The behavior of several enzymes was studied during rat heart development (4 days before birth to adult stage). Hexokinase has its highest activity during the fetal period; it decreases at birth and remains with low activity in the adult. The alpha-glycerophosphate dehydrogenase and alpha-glycerophosphate oxidase profiles are similar up to the 15th day of development. From there onwards, both profiles diverge, the cytoplasmic activity increasing 3-fold, while the mitochondrial activity remains unchanged. The developmental profiles of the malate dehydrogenases are almost parallel. The development of citrate synthase and succinate dehydrogenase results in a 2- to 4-fold increase in their activities. However, ATPase increases dramatically (20-fold) over the same period. With respect to the enzymes of the adenine nucleotide metabolism, adenylate kinase is fully expressed throughout all ages examined, showing no variation during development. AMP deaminase and creatine kinase increase during development, the cytoplasmic creatine kinase reaching a high level at birth whereas the increases of the mitochondrial enzymes take place gradually during development.
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PMID:Development of enzymes of energy metabolism in rat heart. 623 Jan 12

Mitochondria were isolated from whole homogenates of normal liver and Novikoff hepatomas using reorienting rate zonal centrifugation on sucrose gradients. The activities of several mitochondrial-specific enzymes and ultrastructure were compared in the two tissues. Our results indicate that cytochrome oxidase, lipoamide dehydrogenase, malate dehydrogenase, and succinate dehydrogenase activities are all higher in liver homogenates than in Novikoff hepatoma homogenates. Mitochondrial hexokinase, however, is much greater in the hepatoma than in liver. The activity of these enzymes in isolated mitochondria displayed a much different pattern. Both cytochrome oxidase and succinate dehydrogenase activities were higher in hepatoma mitochondria than in liver mitochondria. Lipoamide dehydrogenase and malate dehydrogenase, conversely, were higher in liver mitochondria. Hexokinase was found to be virtually absent in liver mitochondria but plentiful in hepatoma mitochondria. Ultrastructural studies have shown that the hepatoma mitochondria are much smaller in size, which results in a decreased rate of migration into the gradient. These studies have also shown that normal liver consists of predominantly "condensed" forms of mitochondria, whereas hepatoma contained a majority of "twisted" species. Experiments using 1% bovine serum albumin in the homogenization procedures and in the gradient have confirmed earlier observations that bovine serum albumin is essential for optimal isolation of neoplastic mitochondria.
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PMID:Characteristics of mitochondria isolated by rate zonal centrifugation from normal liver and Novikoff hepatomas. 624 94

Tissue samples were taken from the gastrocnemius muscle of 26 randomly selected, glucose-tolerant, 48-yr-old men. Hexokinase, phosphorylase, lactate dehydrogenase (LDH), succinate dehydrogenase, and lipoprotein lipase activity (LPLA), as well as the area per fiber type and capillary density, were determined. Mean fiber area correlated positively with relative body weight (r equals 0.53, P less than 0.01), but capillary density did not. The result is that, in cases of high body weight, each capillary supplies a larger muscle fiber area. Serum insulin concentration in the fasting state correlated positively with body weight (r equals 0.77, P less than 0.001) and with mean fiber area per capillary (r equals 0.87; P less than 0.001). Only during the latter part of an oral glucose tolerance test (OGTT) did blood glucose concentrations correlate with relative body weight and mean fiber area per capillary (r equals 0.42, r equals 0.51, P less than 0.05). A stepwise multiple regression analysis showed that the different muscle morphology measurements could account for 3/4 of the variation in the fasting serum insulin concentration, the fasting insulin/glucose ratio, and the blood glucose concentration at 120 min in the OGTT. Of the intracellular enzymes, only LDH (r equals -0.71, P less than 0.001) correlated with the mean fiber area per capillary. LPLA correlated with capillary density (r equals 0.66, P less than 0.001), and, long with the muscle morphology measurements, could account for 3/4 of the variation in serum triglyceride concentrations. The results show that a large mean muscle fiber area/capillary ratio indicates a morphologic imbalance, which is related to both glucose tolerance and various degrees of insulin sensitivity.
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PMID:Body weight, skeletal muscle morphology, and enzyme activities in relation to fasting serum insulin concentration and glucose tolerance in 48-year-old men. 701 1

The presence of 14 enzymes was investigated using purified spores of the microsporidian Nosema grylli from fat body of the crickets Gryllus bimaculatus. Glucose 6-phosphate dehydrogenase (EC 1.1.1.49), phosphoglucomutase (EC 5.4.2.2), phosphoglucose isomerase (EC 5.3.1.9), fructose 6-phosphate kinase (EC 2.7.1.11), aldolase (EC 4.1.2.13), 3-phosophoglycerate kinase (EC 2.7.2.3), pyruvate kinase (EC 2.7.1.40) and glycerol 3-phosphate dehydrogenase (EC 1.1.1.8) were detected with activities of 15 +/- 1, 7 +/- 1, 1,549 +/- 255, 10 +/- 1, 5 +/- 1, 16 +/- 4, 6 +/- 1 and 16 +/- 2 nmol/min mg protein, respectively. Hexokinase (EC 2.7.1.1), NAD-dependent malate dehydrogenase (EC 1.1.1.37), malic enzyme (EC 1.1.1.40), lactate dehydrogenase (EC 1.1.1.27), alcohol dehydrogenase (EC 1.1.1.1) and succinate dehydrogenase (EC 1.3.99.1) were not detectable. These results suggest the catabolism of carbohydrates in microsporidia occurs via the Embden-Meyerhof pathway. Glycerol 3-phosphate dehydrogenase may reoxidize NADH which is produced by glyceraldehyde 3-phosphate dehydrogenase in glycolysis.
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PMID:Activities of enzymes of carbohydrate and energy metabolism of the spores of the microsporidian, Nosema grylli. 918 13

Muscle contraction causes an increase in activity of 5'-AMP-activated protein kinase (AMPK). This study was designed to determine whether chronic chemical activation of AMPK will increase mitochondrial enzymes, GLUT-4, and hexokinase in different types of skeletal muscle of resting rats. In acute studies, rats were subcutaneously injected with either 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR; 1 mg/g body wt) in 0.9% NaCl or with 0.9% NaCl alone and were then anesthetized for collection and freezing of tissues. AMPK activity increased in the superficial, white region of the quadriceps and in soleus muscles but not in the deep, red region of the quadriceps muscle. Acetyl-CoA carboxylase (ACC) activity, a target for AMPK, decreased in all three muscle types in response to AICAR injection but was lowest in the white quadriceps. In rats given daily, 1 mg/g body wt, subcutaneous injections of AICAR for 4 wk, activities of citrate synthase, succinate dehydrogenase, and malate dehydrogenase were increased in white quadriceps and soleus but not in red quadriceps. Cytochrome c and delta-aminolevulinic acid synthase levels were increased in white, but not red, quadriceps. Carnitine palmitoyl-transferase and hydroxy-acyl-CoA dehydrogenase were not significantly increased. Hexokinase was markedly increased in all three muscles, and GLUT-4 was increased in red and white quadriceps. These results suggest that chronic AMPK activation may mediate the effects of muscle contraction on some, but not all, biochemical adaptations of muscle to endurance exercise training.
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PMID:Activation of AMP-activated protein kinase increases mitochondrial enzymes in skeletal muscle. 1084 39

Campbell, J. J. R. (The University of British Columbia, Vancouver, B.C., Canada), Loretta A. Hogg, and G. A. Strasdine. Enzyme distribution in Pseudomonas aeruginosa. J. Bacteriol. 83:1155-1160. 1962.-Previous studies on the distribution of enzymes in bacteria have indicated that, although individual enzymes were predominantly associated with a particular cellular structure, nevertheless some of the enzyme appeared to be present in all cellular fractions. In the present work with Pseudomonas aeruginosa, it was shown that, in general, an enzyme is present in only one cellular component. Hexokinase, glucose-6-phosphate dehydrogenase, 6-phosphogluconic dehydrogenase, gluconic dehydrogenase, malic dehydrogenase, fumarase, isocitric dehydrogenase, isocitritase, and catalase were detected only in the soluble cytoplasm of the cell. Glucose oxidase and succinic dehydrogenase were detected only in the "ghost" fraction. Diphosphopyridine nucleotide oxidase was present in both "ghost" and ribosomal fractions but was most concentrated in the "ghost". Although adenylic kinase was found to be present in all fractions, it was possible to fractionate cells so that almost all of the activity was associated with the soluble cytoplasm a minor amount being associated with the "ghost." Adenosine triphosphatase was most concentrated in the "ghost" but appreciable activity appeared in the cytoplasm. Polynucleotide phosphorylase appeared to be the only enzyme that was convincingly associated with the ribosomes. However, a small amount of activity was associated with the soluble cytoplasm and with the "ghosts."
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PMID:Enzyme distribution in Pseudomonas aeruginosa. 1387 40

Effect of Capparis spinosa (C. spinosa) and Acacia arabica (A. arabica) dry powder as plant molluscicide on some glycolytic and gluconeogenic enzymes on snail tissues, was investigated. Lactate debydrogenase (LDH), Pyruvate Kinase (PK), Hexokinase (HK), phosphofructokinase (PFK), glucose phosphate isomerase (GPI) as important glycolytic enzymes, were markedly manipulated by both plants when measured one day and one week post-treatment. On the other hand glucose-6-phosphatase (G-6Pase), fructose 1.6 diphosphatase (FDpase), phosphoenol pyruvate carboxykinase (PEPCK) as gluconeogenic enzymes were significantly affected by the moluscicidal plants. In addition, some other parameters as glycogen, glucose, total protein, 5-nucleotidase alpha-hydroxybutyrate dehydrogenase (HBDH) and succinate dehydrogenase (SDH) as kreb's cycle enzyme were tested. As conclusion, LC25 and LC50 concentrations of C. spinosa and A. arabica might render B. alexandrina physiologically unsuitable for S. mansoni infection.
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PMID:Induced changes in biochemical parameters of the molluscan tissues non-infected using two potent plants molluscicides. 1528 76

Glucose and oxygen are vital for the brain, as these molecules provide energy and metabolic intermediates that are necessary for cell function. The glycolysis pathway and mitochondria play a pivotal role in cell energy metabolism, which is closely related to reactive oxygen species (ROS) production. Hexokinase (HK) is a key enzyme involved in glucose metabolism that modulates the level of brain mitochondrial ROS by recycling ADP for oxidative phosphorylation (OxPhos). Here, we hypothesize that the control of mitochondrial metabolism by hexokinase differs in distinct areas of the brain, such as the cortex and hypothalamus, in which ROS might function as signaling molecules. Thus, we investigated mitochondrial metabolism of synaptosomes derived from both brain regions. Cortical synaptosomes (CSy) show a predominance of glutamatergic synapses, while in the hypothalamic synaptosomes (HSy), the GABAergic synapses predominate. Significant differences of oxygen consumption and ROS production were related to higher mitochondrial complex II activity (succinate dehydrogenase-SDH) in CSy rather than to mitochondrial number. Mitochondrial HK (mt-HK) activity was higher in CSy than in HSy regardless the substrate added. Mitochondrial O2 consumption related to mt-HK activation by 2-deoxyglucose was also higher in CSy. In the presence of substrate for complex II, the activation of synaptosomal mt-HK promoted depuration of ROS in both HSy and CSy, while ROS depuration did not occur in HSy when substrate for complex I was used. The impact of the mt-HK inhibition by glucose-6-phosphate (G6P) was the same in synaptosomes from both areas. Together, the differences found between CSy and HSy indicate specific roles of mt-HK and SDH on the metabolism of each brain region, what probably depends on the main metabolic route that is used by the neurons.
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PMID:Mitochondria-Bound Hexokinase (mt-HK) Activity Differ in Cortical and Hypothalamic Synaptosomes: Differential Role of mt-HK in H2O2 Depuration. 2911 35


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