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:1.3.5.1 (succinate dehydrogenase)
8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Growth of Mycobacterium phlei under low oxygen tension resulted in specific activities two to twenty times lower for formate dehydrogenase, malate dehydrogenase, beta-hydroxybutyrate dehydrogenase, lactate oxidase and NADH dehydrogenase than when cultures were grown under high aeration. An increase in fumarate reductase and succinate dehydrogenase occurred with M. phlei grown under low oxygen tension. Malate: vitamin K dehydrogenase and glucose-6-phosphate dehydrogenase activity were not significantly affected by the oxygen tension used to grow the bacteria, and neither culture contained a lactate dehydrogenase. With growth of M. phlei in conditions of low oxygen tension, cytochrome a was not detected, but cytochrome b was prominent in membranes and cytochrome c was present in the soluble fraction.
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PMID:Influence of oxygen tension on the respiratory activity of Mycobacterium phlei. 318 14

The oxidative metabolic potential of Setaria digitata, a filarial parasite found in the intraperitoneal cavity of cattle, was investigated. These worms showed active wriggling movements which were not affected by respiratory poisons such as cyanide, rotenone and malonate. They also possessed cyanide-insensitive and glucose-independent oxygen consumption pathways. By differential centrifugation of sucrose homogenates, a fraction containing mitochondria-like particles was obtained in which the activity of the marker enzyme, succinate dehydrogenase, was recovered. This fraction catalysed succinate- and NADH-dependent reduction of both cytochrome c and dyes. Oxygen uptake found with succinate, NADH and ascorbate as substrates was not sensitive to cyanide. Cytochromes could not be detected in either this fraction or homogenates of the worms. H2O2 generation with a number of substrates and lipid peroxidation by measuring malondialdehyde formed as well as by accompanying oxygen uptake were demonstrated in the mitochondria-like particles. A lipid quinone, possibly with a short side chain and related to ubiquinone, was detected in the worms. The results suggested the existence of two cyanide-insensitive oxygen-consuming reactions in Setaria: one respiratory substrate-independent lipid peroxidation, and a second substrate-dependent reaction that requires an auto-oxidizable quinone but not a cytochrome system.
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PMID:Oxidative activities in mitochondria-like particles from Setaria digitata, a filarial parasite. 322 30

1. Increased specific activities of cytochrome c oxidase, catalase, succinate dehydrogenase, succinate-cytochrome c oxidoreductase, NADH-cytochrome c oxidoreductase and malate dehydrogenase were observed during glucose de-repression of Schizosaccharomyces pombe. 2. The cell-cycle of this organism was analysed by three different methods: (a) harvesting of cells at intervals from a synchronous culture, (b) separation of cells by rate-zonal centrifugation into different size classes and (c) separation of cells by isopycnic-zonal centrifugation into different density classes. 3. Measurement of enzyme activities during the cell-cycle showed that all the enzymes assayed [cytochrome c oxidase, catalase, acid p-nitrophenylphosphatase, NADH-dehydrogenase, NADH-cytochrome c oxidoreductase, NADPH-cytochrome c oxidoreductase, succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase (NADP) and fumarate hydratase] show periodic expression as ;peaks'. 4. Cytochrome c oxidase shows a single maximum at 0.67 of a cycle, whereas succinate dehydrogenase exhibits two maxima separated by 0.5 of a cell-cycle. 5. All other enzymes assayed showed two distinct maxima per cell-cycle; for catalase, malate dehydrogenase and NADPH-cytochrome c oxidoreductase there is the possibility of multiple fluctuations. 6. The single maximum of cytochrome c oxidase appears at a similar time in the cycle to one maximum of each of the other enzymes studied, except for NADH dehydrogenase. 7. These results are discussed with reference to previous observations on the expression of enzyme activities during the cell-cycle of yeasts.
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PMID:Oscillations of enzyme activities during the cell-cycle of a glucose-repressed fission-yeast Schizosaccharomyces pombe 972h-. 414 72

1. The specific activities of cytochrome c oxidase, catalase, succinate dehydrogenase, succinate-cytochrome c oxidoreductase, NADH-cytochrome c oxidoreductase, and NADPH-cytochrome c oxidoreductase in mid-exponential-phase batch cultures of glycerol-grown Schizosaccharomyces pombe indicated that the organisms were catabolite-de-repressed. 2. In cultures growing synchronously in the presence of glycerol as sole carbon source, the respiration rate showed two abrupt increases at about 0.45 and 0.95 of the cell-cycle and remained constant in the periods between successive rises. 3. Catalase, succinate dehydrogenase, NADH-cytochrome c oxidoreductase and acid p-nitrophenyl-phosphatase all showed peak patterns of expression in synchronous cultures. 4. Cytochrome c oxidase and cytochromes a+a(3) both showed step patterns of expression with two rises per cell-cycle. 5. Cytochromes c(548), b(554) and b(560) all followed similar time-courses in step patterns of expression, but these were distinct from, and more complex than, that of cytochromes a+a(3). 6. These results are compared with those previously obtained with glucose-grown cultures, and the part played by catabolite repression in the expression of respiratory activities in the cell-cycle is assessed.
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PMID:Changes in respiratory activities during the cell-cycle of the fission yeast Schizosaccharomyces pompe 972h--growing in the presence of glycerol. 415 30

Gossypol was examined in relation to its effect on certain enzymes and enzyme complexes associated with the tricarboxylic acid cycle and the electron transport system. Succinic dehydrogenase and cytochrome oxidase activity from sweet potato was completely inhibited by gossypol at 7.5 x 10(-3)m and 2.0 x 10(-3)m, respectively. Succinoxidase activity of the same preparations was fully inhibited at a lower concentration, 2.5 x 10(-4)m. This concentration did not affect either succinic dehydrogenase or cytochrome oxidase, the primary and terminal enzymes of the succinoxidase complex. The nature of the intermediate step or steps inhibited at this concentration is not yet known. Gossypol was further shown to inhibit phosphorylation at concentrations having no appreciable effect on oxidation. Inhibition in general was not reduced by increased substrate concentrations in the enzyme systems examined, with the exception of cytochrome c for cytochrome oxidase. Bovine serum albumin was partially effective in reducing gossypol inhibition, provided that it was present before enzyme exposure to gossypol.
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PMID:Effect of gossypol on some oxidative respiratory enzymes. 428 49

1. Euglena cells were grown in culture media containing either 20mm-phosphate or 20mum-phosphate, with ethanol or glucose as the sole source of carbon, and gassed with either air+carbon dioxide (95:5) or oxygen+carbon dioxide (95:5) at atmospheric pressure. 2. After growth in low-phosphate medium with ethanol as substrate, the cells developed signs of oxygen toxicity, as indicated by a decreased rate of respiration, a decreased net synthesis of paramylum and a failure to resume growth on replenishment of phosphate. 3. After growth in low-phosphate medium with glucose as substrate, the signs of oxygen toxicity were less apparent. 4. During phosphate deprivation the carotenoid content of Euglena increased more than threefold. This increase was largely prevented by exposure of the cells to oxygen+carbon dioxide (95:5) during growth. Oxygenation appears to interfere with ring closure of the common carotenoid precursor. 5. Mitochondria obtained from Euglena exposed to oxygen during phosphate deprivation, i.e. when signs of oxygen toxicity were evident, had greatly decreased activities of succinate dehydrogenase, succinate-cytochrome c oxidoreductase and NADH-cytochrome c oxidoreductase, compared with mitochondria obtained from Euglena exposed to oxygen in medium containing 20mm-phosphate.
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PMID:Metabolic changes during phosphate deprivation in euglena in air and in oxygen. 429 27

Saccharomyces cerevisiae was grown in batch culture over a wide range of oxygen concentrations, varying from the anaerobic condition to a maximal dissolved oxygen concentration of 3.5 muM. The development of cells was assayed by measuring amounts of the aerobic cytochromes aa(3), b, c, and c(1), the cellular content of unsaturated fatty acids and ergosterol, and the activity of respiratory enzyme complexes. The half-maximal levels of membrane-bound cytochromes aa(3), b, and c(1), were reached in cells grown in O(2) concentrations around 0.1 muM; this was similar to the oxygen concentration required for half-maximal levels of unsaturated fatty acid and sterol. However, the synthesis of ubiquinone and cytochrome c and the increase in fumarase activity were essentially linear functions of the dissolved oxygen concentration up to 3.5 muM oxygen. The synthesis of the succinate dehydrogenase, succinate cytochrome c reductase, and cytochrome c oxidase complexes showed different responses to changes in O(2) concentration in the growth medium. Cyanide-insensitive respiration and P(450) cytochrome content were maximal at 0.25 muM oxygen and declined in both more anaerobic and aerobic conditions. Cytochrome c peroxidase and catalase activities in cell-free homogenates were high in all but the most strictly anaerobic cells.
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PMID:Respiratory development in Saccharomyces cerevisiae grown at controlled oxygen tension. 435 79

The stimulation of succinate-cytochrome c reductase in Jerusalem artichoke mitochondria by lowering osmolarity was found to be associated with conformational changes in the inner membrane rather than with rupture of the outer membrane. This conclusion is based on the following evidence. (1) When the activation of succinate dehydrogenase was measured by using either K(3)Fe(CN)(6) or exogenous cytochrome c as an electron acceptor, electron flow to cytochrome c was always 7% of that to K(3)Fe(CN)(6) throughout the activation process. (2) The rate of exogenous cytochrome c reduction by succinate and NADH was directly related to the maximum rate of electron flow as determined by oxygen utilization. These two observations are not consistent with the low rate of succinate-cytochrome c reductase being limited by a permeability barrier at the outer membrane. (3) In addition to stimulating the succinate-cytochrome c reductase, lowering the osmolarity caused simultaneous changes in the permeability of the inner membrane to ferricyanide and NADH. The data show that lowering the osmolarity results in progressive changes in the permeability of the inner membrane. The first change detected was an increased permeability to K(3)Fe(CN)(6), then a simultaneous increase in accessibility of the respiratory chain to exogenous cytochrome c and an increased permeability to NADH, followed finally by rupture as measured by the release of malate dehydrogenase.
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PMID:The influence of osmolarity on the reduction of exogenous cytochrome c and permeability of the inner membrane of Jerusalem artichoke mitochondria. 437 72

1. Exposure of Astasia longa to oxygen+carbon dioxide (95:5) at atmospheric pressure leads to an inhibition of growth rate and of respiration. Growth resumes at the normal rate as soon as the oxygenation is discontinued, but respiration recovers more slowly. 2. Mitochondria prepared from cells exposed to oxygen+carbon dioxide (95:5) during growth have considerably decreased activities of succinate-cytochrome c oxidoreductase, NADH-cytochrome c oxidoreductase, succinate dehydrogenase and succinate oxidase activities as compared with mitochondria obtained from cells exposed to air+carbon dioxide (95:5). Cytochrome oxidase activity is not appreciably inhibited by exposure of the cells to 95% oxygen. 3. The mitochondrial fraction of Astasia contains rhodoquinone. The rhodoquinone concentration increases in cells exposed to 95% oxygen. The content of ergosterol-containing compounds also increases in the mitochondria of cells exposed to 95% oxygen. There is little change in the ubiquinone content of the mitochondrial fraction. The ubiquinone of Astasia appears to be ubiquinone-45.
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PMID:Oxygen toxicity in Astasia. 558 20

Early effects of choline deficiency were studied in rats. Nonphospholipid ("neutral lipid") and phospholipid were measured in plasma and in three fractions of a liver homogenate: sediment, supernatant fraction, and "floating fat." A single choline-deficient meal caused significant aberrations from the typical diurnal changes observed in the lipid fractions of the controls. These changes occurred in the following sequence: (a) failure of phospholipid to increase, after feeding, in the sediment fraction; (b) increase of neutral lipid, compared with controls, exclusively in the floating fraction; and (c) failure of neutral lipid to return to control levels. The rate of accumulation of neutral lipid increased during the first 4 days of deficiency. The occurrence of NADH-cytochrome c dehydrogenase in the floating fat and the absence of succinate dehydrogenase activity point to microsomal origin of the floating fat. Early effects of choline deficiency on plasma lipids were limited to phospholipid, and occurred later than changes in the liver. Plasma nonphospholipid levels were unchanged during the first 2 days; this does not support impaired secretion or transportation of glyceride as the cause of fatty liver in the early stages of choline deficiency.
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PMID:Diurnal changes in liver and plasma lipids of choline-deficient rats. 590 Feb 9


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