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 intracellular localization of a Cl--HCO3--ATPase, which is inhibited by SCN-, was studied in the gills of the rainbow trout, Salmo gairdneri. This activity can be measured in the absence of contamination by mitochondria (i.e., in the absence of succinate dehydrogenase or cytochrome c oxidase activities). The distribution of the 5'-nucleotidase and of the ATPase stimulated by Cl- and HCO3- after sucrose density gradient centrifugation of the microsomal fraction was compared. Because those activities cannot be separated, it is postulated that the anion-stimulated ATPase is located in the plasma membrane. The activation of this microsomal anion ATPase by chloride has been studied extensively. The possible role of the Cl--HCO3--ATPase of trout gills in the Cl-/HCO3- exchange and in the regulation of the internal acid-base balance is discussed.
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PMID:Cl--HCO3--ATPase in gills of the rainbow trout: evidence for its microsomal localization. 644 66

We investigated the changes of the inner-membrane components and the electron-transfer activities of bovine heart submitochondrial particles induced by the lipid peroxidation supported by NADPH in the presence of ADP-Fe3+. Most of the polyunsaturated fatty acids were lost as a result of the peroxidation, and phospholipids were changed to polar species. Ubiquinone was also modified to polar substances as the peroxidation proceeded. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis showed the disappearance of 27000-Mr and 30000-Mr proteins and the appearance of highly polymerized substances. Flavins and cytochromes were not diminished, but the respiratory activity was lost. The reactions of NADH oxidase and NADH-cytochrome c reductase were most sensitive to the peroxidation, followed by those of succinate oxidase and succinate-cytochrome c reductase. Succinate dehydrogenase and duroquinol-cytochrome c reductase were inactivated by more extensive peroxidation, but cytochrome c oxidase was only partially inactivated. NADH-ferricyanide reductase was not inactivated. The pattern of the inactivation indicated that the lipid peroxidation affected the electron transport intensively between NADH dehydrogenase and ubiquinone, and moderately at the succinate dehydrogenase step and between ubiquinone and cytochrome c.
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PMID:Alteration of inner-membrane components and damage to electron-transfer activities of bovine heart submitochondrial particles induced by NADPH-dependent lipid peroxidation. 708 19

It has been suggested that aromatic aldehydes may reduce cytochrome c [Wolf et al. Fedn Proc. 39 (3), 1013 (1980)]. Therefore, interaction of the aromatic aldehydes, p-anisaldehyde, benzaldehyde, p-tolualdehyde, p-carboxybenzaldehyde, p-chlorobenzaldehyde and p-nitrobenzaldehyde, with rat liver mitochondria was examined in vitro. Although both pyruvate/malate- and succinate-mediated respiration, as well as that mediated by other citric acid cycle intermediates, were inhibited by the aromatic aldehydes (0.5 to 1.0 mM), cytochrome c oxidase was not inhibited by aromatic aldehydes (1.0 to 20 mM). There was a marked inhibition of succinic dehydrogenase and both ADP- and DNP-stimulated respiration by benzaldehyde (2 to 20 mM). Since both pyruvate/malate- and succinate-mediated respiration were inhibited by the aromatic aldehydes without inhibition of cytochrome c oxidase, several sites of inhibition, possibly both at the site of transport of substrates and the active enzymes, may exist. Benzaldehyde, 300 microM, inhibited pyruvate/malate-mediated state 3 respiration by 50% which suggests that no additional functional group or metabolism to another species is required for these inhibitory effects.
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PMID:Interaction of aromatic aldehydes with isolated rat liver mitochondria. 711 22

Light and heavy membrane fractions have been isolated by equilibrium sucrose density centrifugation from Rhodopseudomonas capsulata 938 GCM grown aerobically in the dark (chemotrophically) and anaerobically in the light (phototrophically). The densities of the light and heavy fractions from phototrophic cells were 1.1004 to 1.1006 and 1.1478, respectively, and the densities of the light and heavy fractions from chemotrophic cells were 1.0957 to 1.0958 and 1.1315, respectively. Both fractions were active in photochemical and respiratory functions and in electron transport-coupled phosphorylation. The light membrane fraction isolated from chemotrophic cells contained the reaction center and the light-harvesting pigment-protein complex B 870, but not the variable light-harvesting complex B 800-850. A small amount of the complex B 800-850 was present in the light fraction isolated from phototrophically grown cells, but it was not energetically coupled to the photosynthetic apparatus. From inhibitor studies, difference spectroscopy, and measurement of enzyme activities it was tentatively concluded that the light membrane fraction contains only the reduced nicotinamide adenine dinucleotide-oxidizing electron transport chain having a KCN-insensitive, low-potential cytochrome c oxidase, whereas the heavy fraction contains additionally the succinate dehydrogenase and a high-potential cytochrome b terminal oxidase sensitive to KCN. The light membrane fraction was more labile than the heavy fraction in terms of phosphorylating activity.
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PMID:Comparative studies of two membrane fractions isolated from chemotrophically and phototrophically grown cells of Rhodopseudomonas capsulata. 720 41

The acute effects of ethanol on the nervous system are thought to be associated with disturbance of neural membrane function. In the present study the effects of ethanol, its immediate metabolite, acetyldehyde, and tertiary butanol which is not further metabolized to an aldehyde, on selected membrane-bound enzymes were examined in vitro in rat brain. The enzymes included acetylcholinesterase, succinate dehydrogenase, Na+K+-ATPase and cytochrome c oxidase. At concentrations ranging from 0.07 - 2% w/v (15 - 435 mM) ethanol did not produce significant inhibition of any of the enzymes tested. On the other hand acetaldehyde at concentrations ranging from 0.01 - 0.5% w/v (2 - 114 mM) showed marked inhibition of all the abovementioned enzymes except acetylcholinesterase. The responses of the various enzymes to tertiary butanol were intermediate between those obtained with ethanol and acetaldehyde. Further studies are in progress to evaluate the significance of these findings to the understanding of alcohol intoxication, tolerance and dependence in man.
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PMID:Effect of ethanol and acetaldehyde on membrane-bound enzymes in rat brain. 742 41

The evaluation of the severity of progressive external ophthalmoplegia (PEO) with ragged-red fibers in muscle, at the onset of the disease, when PEO is most often the only presenting symptom, is a difficult problem in neurological practice. In order to address that issue, we have performed a comparative analysis of the clinical, morphological and molecular characteristics of 43 patients affected with that form of ocular myopathy. Quantification of mitochondrial accumulation was performed with an image analysis application on muscle sections stained with succinate dehydrogenase histochemical reaction. The proportion of muscle fibres appearing as cytochrome c oxidase deficient was used as an index of the muscle-energy defect. Muscle mitochondrial DNA deletions were detected, localized and quantitated by Southern blot analysis. Point mutations were screened in five transfer RNA genes in the mtDNA (tRNA(Leucine (UUR)), tRNA(Lysine), tRNA(Glutamine), tRNA(Isoleucine) and tRNA(Formylmethionine)) by a denaturing gradient gel electrophoresis technique. This investigation confirmed the high frequency of mtDNA deletions or point mutations in PEO. At the onset of the disease, no clinical, morphological or molecular features could predict whether PEO would remain isolated or become part of a more severe multisystem disease. However, patients with mtDNA deletions were characterized by more severe ophthalmoplegia of earlier onset. Their muscle alterations were roughly parallel in severity to the proportion of deleted mtDNA molecules in muscle. Patients with a multitissular disease and mtDNA deletions were always sporadic cases and their clinical presentation was, most often, closely related to Kearns Sayre syndrome.
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PMID:Chronic progressive external ophthalmoplegia with ragged-red fibers: clinical, morphological and genetic investigations in 43 patients. 749 74

The Ca(2+)-independent form of nitric oxide synthase was induced in rat neonatal astrocytes in primary culture by incubation with lipopolysaccharide (1 microgram/ml) plus interferon-gamma (100 U/ml), and the activities of the mitochondrial respiratory chain components were assessed. Incubation for 18 h produced 25% inhibition of cytochrome c oxidase activity. NADH-ubiquinone-1 reductase (complex I) and succinate-cytochrome c reductase (complex II-III) activities were not affected. Prolonged incubation for 36 h gave rise to a 56% reduction of cytochrome c oxidase activity and a 35% reduction in succinate-cytochrome c reductase activity, but NADH-ubiquinone-1 reductase activity was unchanged. Citrate synthase activity was not affected by any of these conditions. The inhibition of the activities of these mitochondrial respiratory chain complexes was prevented by incubation in the presence of the specific nitric oxide synthase inhibitor NG-monomethyl-L-arginine. The lipopolysaccharide/interferon-gamma treatment of the astrocytes produced an increase in glycolysis and lactate formation. These results suggest that inhibition of the mitochondrial respiratory chain after induction of astrocytic nitric oxide synthase may represent a mechanism for nitric oxide-mediated neurotoxicity.
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PMID:Nitric oxide-mediated inhibition of the mitochondrial respiratory chain in cultured astrocytes. 751 65

Three patients from a large consanguineous family, and one unrelated patient had exercise intolerance since early childhood and improved by supplementation with a high dosage of riboflavin. This was confirmed by higher endurance power in exercise testing. Riboflavin had been given because complex I, which contains riboflavin in FMN, one of its prosthetic groups, had a very low activity in muscle. Histochemistry showed an increase of subsarcolemmal mitochondria. The low complex I activity contrasted with an increase of the activities of succinate dehydrogenase, succinate-cytochrome c oxidoreductase and cytochrome c oxidase. Isolated mitochondria from these muscle specimens proved deficient in oxidizing pyruvate plus malate and other NAD(+)-linked substrates, but oxidized succinate and ascorbate at equal or higher levels than controls. Two years later a second biopsy was taken in one of the patients, and the activity of complex I had increased from 16% to 47% of the average activity in controls. In the four biopsies, cytochrome c oxidase activity correlated negatively with age. We suspect that this is due to reactive oxygen species generated by the proliferating mitochondria and peroxidizing unsaturated fatty acids of cardiolipin. Three of the four patients had low blood carnitine, and all were found to have hypocarnitinemic family members.
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PMID:Riboflavin-responsive complex I deficiency. 759 30

We sought a relationship between abnormalities of mitochondrial DNA (mtDNA) and muscle pathology in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS) at the single fiber level, using histochemistry, in situ hybridization, and single fiber PCR. Most type 1 ragged-red fibers (RRF) showed positive cytochrome c oxidase (COX) activity at the subsarcolemmal region, while type 2 RRF showed little COX activity. However, there was no difference in the amount of total (mutant and wild-type) mtDNAs and the proportion of mutant mtDNA between type 1 RRF and type 2 RRF. These observations suggest that mitochondrial proliferation and nuclear factors affect muscle pathology, including COX activity, in MELAS. Total mtDNAs were greatly increased in RRF. The proportion of mutant mtDNA was significantly higher in RRF than in non-RRF. The amount of both wild-type and mutant mtDNAs was increased in RRF in MELAS, which fact does not support the contention of a replicative advantage of mutant mtDNA. The proportion of mutant mtDNA was significantly higher in the strongly succinate dehydrogenase-reactive blood vessels (SSV) than in non-SSV. The similar morphological behavior in these vessels and fibers suggests that increased mutant mtDNA is responsible for mitochondrial proliferation and dysfunction in both tissues. It seems likely that systemic vascular abnormalities involving cerebral vessels lead to the evolution of strokelike episodes in MELAS.
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PMID:Mitochondrial DNA mutation and muscle pathology in mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes. 760 11

Using in situ hybridization, we studied muscle biopsy specimens from 4 patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Three of the 4 patients with MELAS had a mutation at position 3243 of mitochondrial DNA (mtDNA) in the transfer RNALeu(UUR) gene, and the other patient had a mutation at position 3271 in the same transfer RNALeu(UUR) gene. Quantitative analysis using Southern blot hybridization and polymerase chain reaction showed 80 to 90% mutant mtDNA in muscle. In situ hybridization analysis showed that total mtDNAs (both normal and mutant) were extremely increased in blood vessels with high succinate dehydrogenase activity (strongly succinate dehydrogenase-reactive blood vessels) and ragged-red fibers. Cytochrome c oxidase activity in most of these reactive blood vessels and ragged-red fibers was positive. The similar morphological behavior in these vessels and fibers suggests that an increase in mutant mtDNA is responsible for mitochondrial proliferation and dysfunction in both tissues where cytochrome c oxidase is not a primarily defective enzyme. The pattern of expression of genes for mtDNA-encoded ribosomal RNA and the protein-coding region cytochrome c oxidase subunit II were similar in muscle specimens of patients with MELAS, patients with chronic progressive external ophthalmoplegia, and normal control subjects, and also between the two MELAS mutations. These results do not support the hypothesis that impaired transcription termination is a molecular defect in MELAS.
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PMID:Increased mitochondrial DNA in blood vessels and ragged-red fibers in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). 768 81


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