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)

The effects of the peroxisome proliferator, nafenopin, on body temperature, apparent gross food efficiency and activity of interscapular brown adipose tissue (IBAT) peroxisomes and mitochondria of rats acclimated at 23 degrees C or at 32 degrees C have been studied. In 23 degrees C-acclimated rats, nafenopin treatment induced an atrophy of IBAT characterized by a decrease of tissue wet weight, of amounts of mitochondrial and peroxisomal proteins and of mitochondrial total succinate dehydrogenase activity to 67%, 67%, 65% and 57%, respectively of control values. It also resulted in a 1.9-fold stimulation of peroxisome total acyl CoA oxidase activity and had no effect on apparent gross food efficiency or colonic temperature. Acclimation at 32 degrees C per se induced an atrophy of IBAT and a decrease of total catalase and acyl CoA oxidase activities to 23% and 35%, respectively of values obtained in rats acclimated at 23 degrees C. Nafenopin treatment had no effect on IBAT wet weight, on the amounts of mitochondrial and peroxisomal proteins or on total succinate dehydrogenase activity; it resulted in a 2.9- and a 3.7-fold stimulation of the catalase and acyl CoA oxidase activities, respectively with no change in IBAT oxygen consumption. Apparent gross food efficiency was decreased to 54% of control value and colonic temperature increased by 0.91 degrees C. These results may be interpreted in the following way: nafenopin may, at 23 degrees C ambient temperature, induce an extra-heat production in other tissues than IBAT. This extra-heat production is fully compensated via the thermoregulatory feedback control. This compensation cannot occur at thermoneutrality.
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PMID:Effect of nafenopin, a peroxisome proliferator, on energy metabolism in the rat as a function of acclimation temperature. 377 5

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

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

Phagocytic vesicles were obtained by density gradient centrifugation of homogenized rabbit alveolar macrophages that had ingested emulsified paraffin oil contained Oil Red O. The phagocyte vesicles floated and thereby were separated from the soluble fraction and from other cell components which sedimented. The purity of the isolated vesicles was documented by electron microscopy, chemical and enzyme analysis. The vesicles contained 87% of the cell-associated Oil Red O, and were essentially free of DNA, RNA, succinic dehydrogenase, and glucose-6-phosphatase. Acid phosphatase, beta-glucuronidase, and catalase were transferred from the sedimenting fraction to the phagocytic vesicle fraction during phagocytosis, whereas enzyme activities of the soluble fraction remained unchanged. Half of the catalase of resting macrophages was in the pellet fraction and, compared with acid phosphatase, greater amounts of digitonin were required to release full activity. Such differential latency has been described for enzymes of peroxisomes vs. those of lysosomes. Compared with polymorphonuclear leukocyte vesicles studied previously, phagocytic vesicles of macrophages had more electron-dense material and lower Oil Red O:protein, phospholipid:protein, and enzyme:protein ratios. It is thus probable that secondary lysosomes become part of the macrophage vesicle. When paraffin oil particles, the stimulus for phagocytic vesicle formation, were washed away from the macrophages, acquisition of hydrolases by preformed vesicles ceased, i.e. transfer of these enzymes into phagocytic vesicles occurred only during or shortly after the formation of new vesicles. As noted previously by others, the content of acid hydrolases of stimulated alveolar macrophages was doubled in comparison to normal cells. The difference between stimulated and normal macrophages was even more marked when isolated phagocytic vesicles were analyzed. Vesicles from stimulated macrophages had 3-5 times more enzyme activity (per milligram of vesicle protein or per amount of paraffin oil ingested) than did vesicles from normal cells.
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PMID:Isolation and properties of phagocytic vesicles. II. Alveolar macrophages. 501 Nov 3

1. Homogenates of guinea-pig polymorphonuclear leucocytes were separated by differential centrifugation into six particulate fractions and a soluble fraction. 2. The distributions in these fractions of protein, DNA, succinate dehydrogenase, beta-glucuronidase, peroxidase, alkaline phosphatase, acid phosphatase (against p-nitrophenyl phosphate and beta-glycerophosphate), cathepsin, and catalase were compared. 3. Almost all of the DNA sedimented in the first two pellets, indicating that the nuclei were relatively intact. 4. The four hydrolases and peroxidase showed different distribution patterns, although these activities were previously reported to be localized mainly in the single ;granule' fraction isolated from leucocytes. 5. The particles containing peroxidase, acid phosphatase and alkaline phosphatase all exhibited latency. Maximum activity for each enzyme was obtained at roughly similar concentrations of Triton X-100. 6. The acid phosphatase of these cells was distributed between two populations of particles that differed in both sedimentation characteristics and density. The acid phosphatase(s) of the two populations showed slightly different substrate specificities. This bimodal distribution was not an artifact of the procedure used to elicit the cells. 7. Catalase was recovered almost entirely in the soluble fraction and showed no latency in freshly prepared homogenates. No urate oxidase was detected. 8. We conclude that the ;granule' fraction of the polymorphonuclear leucocyte, as isolated by previous workers, contains at least three, probably more, populations of particles with different enzyme contents, and that these cells probably do not contain peroxisomes.
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PMID:The distributions of some granule-associated enzymes in guinea-pig polymorphonuclear leucocytes. 541 96

Analytical subcellular fractionation of tissue whole homogenates and microanalysis of organelle marker enzymes were used to study the activity and subcellular localization of enzymes implicated in HCO3 secretion in rat duodenal and gastric antral mucosae. The following organelles, characterized by their marker enzymes, were located in the density gradients: cytosol (lactate dehydrogenase), plasma membrane (5'-nucleotidase), peroxisomes (catalase), mitochondria (succinate dehydrogenase), endoplasmic reticulum (Tris-resistant alpha-glucosidase), lysosomes (N-beta-acetylglucosaminidase), and brush-border membrane (Zn2+-resistant alpha-glucosidase and alkaline phosphatase). Compared with gastric antrum, rat duodenal mucosa contained over twice the activity of HCO3-ATPase and of Na+-K+-ATPase but less than one-tenth the activity of carbonic anhydrase. Duodenal HCO3-ATPase activity was observed in both mitochondrial and brush-border membrane fractions, whereas antral HCO3-ATPase activity was confined to mitochondria. Na+-K+-ATPase activity was found largely in the basolateral membrane (duodenum) and plasma membrane (antrum). In both tissues carbonic anhydrase activity was localized to the cytosolic fraction. These observations offer further evidence that differing biochemical mechanisms underlie HCO3 secretion by gastric and duodenal epithelia.
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PMID:Activities and subcellular localizations of enzymes implicated in gastroduodenal bicarbonate secretion. 608 73

Cells of the aerotolerant anaerobe Giardia lamblia respire in the presence of oxygen. Endogenous respiration is stimulated by glucose but not by other carbohydrates and Krebs cycle intermediates. Endogenous and glucose-stimulated respiration are insensitive to cyanide, malonate, and 2,4-dinitrophenol, but are inhibited by atabrin and iodoacetamide. G. lamblia produces ethanol, acetate and CO2 both aerobically and anaerobically either from endogenous reserves or exogenous glucose. Molecular hydrogen is not produced. The following enzyme activities were detected in homogenates: hexokinase, fructose-biphosphate aldolase, pyruvate kinase, phosphoenolpyruvate carboxykinase, malate dehydrogenase, malate dehydrogenase (decarboxylating), pyruvate synthase, acetyl-CoA synthetase, alcohol dehydrogenase (NADP+), NADH dehydrogenase, NADPH dehydrogenase, NADPH oxidoreductase and superoxide dismutase. The enzymes of energy and carbohydrate metabolism are nonsedimentable (109 000 x g for 30 min). Activities of lactate dehydrogenase, hydrogenase, phosphate acetyltransferase, acetate kinase, citrate synthase, succinate dehydrogenase, fumarate hydratase and catalase were below the limits of detection. The results suggest the occurrence of glycolysis, energy production by substrate level phosphorylation and a flavin, iron-sulfur protein mediated electron transport system as well as the absence of cytochrome mediated oxidative phosphorylation and functional Krebs cycle.
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PMID:Energy metabolism of the anaerobic protozoon Giardia lamblia. 610 7

Three mitochondrial enzymes, cytochrome oxidase, succinate dehydrogenase, and monoamine oxidase, and two peroxisomal enzymes, catalase and urate oxidase, were measured spectrophotometrically in the postnuclear supernatant prepared from homogenates of normal mucosa and carcinoma of the human colon. The specific activities, in both normal mucosa and carcinoma, varied from patient to patient. However, the difference in these activities between normal mucosa and carcinoma was consistent when patients were compared. The activities of cytochrome oxidase, succinate dehydrogenase, monoamine oxidase, and catalase were greater in normal mucosa than in carcinoma. In contrast, urate oxidase activity increased in carcinoma as compared with normal mucosa. Furthermore, cytochrome oxidase and succinate dehydrogenase decreased proportionally in carcinoma, supporting the concept that the mitochondrial respiration in normal tissue and carcinoma is quantitatively but no qualitatively changed. However, the decrease in monoamine oxidase activity in carcinoma was greater than that observed with other mitochondrial enzyme activities and was irregular. This suggests that a qualitative mitochondrial change may occur in carcinoma. In particular, the ratio between outer membrane enzyme activity and respiratory enzyme activity may be altered.
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PMID:A study of some mitochondrial and peroxisomal enzymes in human colonic adenocarcinoma. 625 83

The distribution of basal and of H2O2-stimulated cyclooxygenase activity in the primary fractions of rat brain homogenates and in the subfractions of crude mitochondrial fraction was studied. For comparison, the localization of H2O2-generating monoamine oxidase (MAO) as well as that of the mitochondrial marker succinate dehydrogenase (SDH) was also examined. H2O2 was generated by MAO using 5 x 10(-4) M noradrenaline (NA) or 2 x 10(-4) M 2-phenylethylamine (PEA) as substrates, or by 25 micrograms glucose oxidase (GOD) per ml in the presence of 1 mM glucose. For nonstimulated (basal) cyclooxygenase, the relative specific activity (RSA) was high in microsomes (1.79) and in the free mitochondria-containing subfraction of the crude mitochondrial fraction (1.94). Parallel distribution of MAO and H2O2-stimulated cyclooxygenase was observed in all fractions studied in the presence of NA. The highest RSA was found in the purified mitochondria for both enzymes (1.85 for MAO and 1.97 for H2O2-stimulated cyclooxygenase). The enrichment of SDH (RSA = 2.21) indicated a high concentration of mitochondria in this fraction. The same distribution of H2O2-stimulated cyclooxygenase was obtained when, instead of the MAO-NA system, hydrogen peroxide was generated by GOD in the presence of glucose. H2O2 generated by deamination of NA or PEA by MAO, or during the enzymatic oxidation of glucose by GOD, caused a threefold increase in mitochondrial endoperoxide formation. Indomethacin (2 x 10(-4) M), catalase (50 micrograms/ml), and pargyline (2 x 10(-4) M) eliminated the MAO-dependent mitochondrial synthesis of PG endoperoxides. The GOD-dependent cyclooxygenase activity in this fraction was abolished by indomethacin or catalase, but not by pargyline. The results show the existence of a mitochondrial cyclooxygenase in brain tissue. The enzyme is sensitive to H2O2 and produces prostaglandin endoperoxides from an endogenous source of arachidonic acid. The identical localization of H2O2-producing MAO and H2O2-sensitive cyclooxygenase suggests a possible coupling between monoamine and arachidonic acid metabolism.
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PMID:Evidence for the localization of hydrogen peroxide-stimulated cyclooxygenase activity in rat brain mitochondria: a possible coupling with monoamine oxidase. 640


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