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)

Exposure of rats to higher environmental temperature (36-37 degrees C) decreased the capacity of their kidney mitochondria to oxidize succinate. The decrease was corrected on the addition of exogenous cytochrome c. Kidney mitochondria of heat-exposed animals showed decreased rates of H2O2 generation when alpha-glycerophosphate, but not succinate, was used as electron donor. These mitochondria also showed decreased activity of alpha-glycerophosphate dehydrogenase but not of succinate dehydrogenase. The content of cytochrome c in kidney mitochondria of heat-exposed animals was low even though the concentration of the pigment in the whole tissue did not decrease. Starvation as well as administration of an antithyroid agent like propylthiouracil simulated some of the effects of heat exposure on kidney mitochondria, but the cytochrome c-dependent reversal of inhibition of oxidation was obtained only in heat exposure.
 ...
PMID:Oxidations in kidney mitochondria of heat-exposed rats: regulation by cytochrome c. 653 33

In isolated rat liver mitochondria, respiration was competitively inhibited by medium chain length (C8 to C13) dicarboxylic acids to different extents: the higher the number of carbon atoms up to C12, the greater the inhibition. In particular, experiments on submitochondrial particles showed that the competitive inhibition concerned the following enzymes: NADH dehydrogenase, succinic dehydrogenase and reduced ubiquinone: cytochrome c oxido-reductase. These results tend to confirm the suggestion that the melanocytotoxic effect of dicarboxylic acids, which are also competitive inhibitors of tyrosinase, may be primarily due to an antimitochondrial effect rather than being tyrosinase-dependent.
 ...
PMID:Antimitochondrial effect of saturated medium chain length (C8-C13) dicarboxylic acids. 670 36

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.
 ...
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

1. Studies on the cytochrome spectra of liver mitochondria from control and glucagon-treated rats in State 4, State 3 and in the presence of uncoupler are reported. 2. The stimulation of electron flow between cytochromes c1 and c observed previously [Halestrap (1978) Biochem. J. 172, 399-405] was shown to be an artefact of Ca2+-induced swelling of mitochondria. 3. When precautions were taken to prevent such swelling, glucagon treatment was shown to enhance the reduction of cytochromes c, c1 and b558 in both State 3 and uncoupled conditions with either succinate or glutamate + malate as substrate. An increase in the reduction of cytochromes b562 and b566 was also seen in some, but not all, experiments. 4. In State 4 with succinate but not glutamate + malate as substrate, cytochromes c, c1, b558, b562 and b566 showed increased reduction. 5. Glucagon stimulated oxidation of duroquinol and palmitoylcarnitine by intact mitochondria and of NADH by disrupted mitochondria. 6. No effect of glucagon on succinate dehydrogenase activity or the temperature-dependence of succinate oxidation could be detected. 7. Glucagon enhanced the inhibition of the respiratory chain by colletotrichin, but not antimycin or 8-heptyl-4-hydroxyquinoline N-oxide. 8. These results are interpreted in terms of a primary stimulation by glucagon of the 'Q cycle' [Mitchell (1976) J. Theor. Biol. 62, 827-367] within Complex III (ubiquinol:cytochrome c oxidoreductase) and a secondary site of action involving stimulation of electron flow into Complex III from the ubiquinone pool. 9. Ageing of mitochondria, hyperosmotic treatment or addition of 20 mM-benzyl alcohol opposed the effects of glucagon treatment on cytochrome spectra and colletotrichin inhibition of respiration. 10. These results support the hypothesis that glucagon exerts its effects on the mitochondria by perturbing the membrane structure.
 ...
PMID:The nature of the stimulation of the respiratory chain of rat liver mitochondria by glucagon pretreatment of animals. 711 29

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.
 ...
PMID:Interaction of aromatic aldehydes with isolated rat liver mitochondria. 711 22

The possible effect of practolol (ICI 50,172) on mitochondrial metabolism was studied. The drug inhibited the oxidation of glutamate, alpha-ketoglutarate and succinate by heart mitochondria. The polarographic determinations showed that practolol is an inhibitor of the oxidative phosphorylation. The activity of NADH-oxidase, NADH-ferricyanide reductase, NADH-cytochrome c redutase was inhibit by the drug; no effect was observed on the succinate dehydrogenase. The electron microscopy of isolated mitochondria treated with practolol showed that the drug promote conformational changes of the mitochondrial membrane, probably concerning with the detergent characteristics of the drug.
 ...
PMID:Studies of practolol on mitochondrial metabolism. 740 72

Rat and pigeon heart mitochondria supplemented with antimycin produce 0.3-1.0nmol of H(2)O(2)/min per mg of protein. These rates are stimulated up to 13-fold by addition of protophores (carbonyl cyanide p-trifluoromethoxyphenylhydrazone, carbonyl cyanide m-chloromethoxyphenylhydrazone and pentachlorophenol). Ionophores, such as valinomycin and gramicidin, and Ca(2+) also markedly stimulated H(2)O(2) production by rat heart mitochondria. The enhancement of H(2)O(2) generation in antimycin-supplemented mitochondria and the increased O(2) uptake of the State 4-to-State 3 transition showed similar protophore, ionophore and Ca(2+) concentration dependencies. Thenoyltrifluoroacetone and N-bromosuccinimide, which inhibit succinate-ubiquinone reductase activity, also decreased mitochondrial H(2)O(2) production. Addition of cyanide to antimycin-supplemented beef heart submitochondrial particles inhibited the generation of O(2) (-), the precursor of mitochondrial H(2)O(2). This effect was parallel to the increase in cytochrome c reduction and it is interpreted as indicating the necessity of cytochrome c(1) (3+) to oxidize ubiquinol to ubisemiquinone, whose autoxidation yields O(2) (-). The effect of protophores, ionophores and Ca(2+) is analysed in relation to the propositions of a cyclic mechanism for the interaction of ubiquinone with succinate dehydrogenase and cytochromes b and c(1) [Wikstrom & Berden (1972) Biochim. Biophys. Acta283, 403-420; Mitchell (1976) J. Theor. Biol.62, 337-367]. A collapse in membrane potential, increasing the rate of ubisemiquinone formation and O(2) (-) production, is proposed as the molecular mechanism for the enhancement of H(2)O(2) formation rates observed on addition of protophores, ionophores and Ca(2+).
 ...
PMID:Enhancement of hydrogen peroxide formation by protophores and ionophores in antimycin-supplemented mitochondria. 740 88

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.
 ...
PMID:Riboflavin-responsive complex I deficiency. 759 30

Electron transport and production of O2-/H2O2 by the NADH dehydrogenase flavin-semiquinone (FMNH.) and ubisemiquinone (UQH.) were studied in a model of in vivo ischemia-reperfusion in rat kidney. H2O2 production rates were assessed in isolated mitochondria using either succinate, with and without antimycin, or malate-glutamate, with and without rotenone. Respiratory activities of isolated mitochondria and activity of NADH- and succinate-cytochrome c reductase and of NADH- and succinate-dehydrogenase in submitochondrial particles were measured to evaluate the electron flux throughout respiratory carriers. The mitochondrial H2O2 production rate was approximately 1.5- and 4-times increased in ischemic and ischemic-reperfused kidneys, respectively. Ischemia caused a marked decrease in the electron transport throughout the NADH-UQ segment with no significant changes either in the NADH dehydrogenase activity or in the electron flux trough the succinate-cytochrome oxidase segment. Reperfusion did not further affect the NADH-ubiquinone segment but markedly inhibited the succinate-supported oxygen consumption, succinate-cytochrome c reductase and succinate dehydrogenase activity. Our results show a redistribution of the electron flux with an increased rate of superoxide anion/hydrogen peroxide production at NADH dehydrogenase in mitochondria subjected to ischemia only. After 10 min reperfusion an impairment of the electron flow at succinate-cytochrome c segment is established and hydrogen peroxide production by UQH. increases up to maximal values becoming the major source of superoxide anion/hydrogen peroxide.
 ...
PMID:Mitochondrial sites of hydrogen peroxide production in reperfused rat kidney cortex. 772 10

Site-directed mutagenesis has been used to introduce cysteine residues into yeast cytochrome c peroxidase and yeast cytochrome c for the purpose of forming site-specific cross-linked intermolecular complexes. This enables the formation of well-defined homogeneous covalently linked complexes for the purpose of relating structure to intramolecular electron transfer. Two complexes have been prepared and analyzed. Complex I has an engineered cysteine at position 290 near the C-terminus of the peroxidase linked to the naturally occurring Cys102 near the C-terminus of yeast cytochrome c. This complex exhibits undetectable rates of intramolecular electron transfer. Complex II has Cys290 of the peroxidase linked to the engineered Cys73 of cyt c. This complex was designed to mimic the crystal structure of the peroxidase-cytochrome c noncovalent complex [Pelletier & Kraut (1992) Science 258, 1748-1755]. Stopped-flow studies show that complex II carries out intramolecular electron transfer from ferrocytochrome c to peroxidase compound I at a rate of approximately 500-800 s-1. This indicates that the binding orientation observed in the crystal structure is competent in rapid intramolecular electron transfer.
 ...
PMID:Site-specific cross-linking as a method for studying intramolecular electron transfer. 775 88


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>