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

---

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

Cryptorchidism of the mature rat testis led to degeneration of the seminiferous tubules and changes in enzyme patterns and activities. Spermatogenic stages 1-4, containing pachytene primary spermatocytes in late meiotic prophase, and stage 5, containing recently formed round spermatids, were damaged by 48 h. Within 96 h stages showed a loss of germinal cells into the lumen and this was almost complete by 192 h. Acid phosphatase showed increased histochemical activity in the basal area of the seminiferous tubule up to 96 h of cryptorchidism, and at 192 h much of the activity was located in large lipidcontaining bodies within the remaining seminiferous epithelium. Total and free biochemical acid phosphatase decreased during cryptorchidism in parallel with cell loss; there were no significant changes in total cathepsin D activity but free enzyme activity was increased throughout the experimental period indicating increased lability of lysosomes in the Sertoli cell. Lactate dehydrogenase activity was mainly tubular but succinate dehydrogenase also showed interstitial activity. Lipoamide dehydrogenase (NADH) was found mainly in the interstitium. During cryptorchidism both lactate and succinate dehydrogenase activity decreased in the tubules parallel to the loss of germinal cells, whereas lipoamide dehydrogenase (NADH) activity increased in both interstitial and tubular areas. It is suggested that the initial lesion in the seminiferous epithelium, produced by cryptorchidism is in the Sertoli cell and that germ cell damage may result from reduced function of the Sertoli cell.
...
PMID:The effect of cryptorchidism on the quantitative histology, histochemistry and hydrolytic enzyme activity of the rat testis. 2 15

Lipoic acid (lip) and 2-oxoglutarate dehydrogenase (sucA) mutants of Escherichia coli K12 exhibit a requirement for exogenous succinate during aerobic growth on glucose minimal medium. Reversion studies have shown that this requirement can be suppressed by gal-linked mutations which inactivate succinate dehydrogenase. Biochemical and genetic studies confirmed that the succinate dehydrogenase gene (sdh) is affected and that suppression is mediated by the same intergenic and indirect mechanism that generates succinate independence in partial revertants of lipoamide dehydrogenase mutants (Creaghan & Guest, 1977). A series of isogenic strains containing all combinations of mutations affecting 2-oxoglutarate dehydrogenase (sucA), succinate dehydrogenase (sdh), isocitrate lyase (aceA) and fumarate reductase (frd) in a background lacking succinate semialdehyde dehydrogenase, was constructed to assess the importance of these enzymes as sources of endogenous succinate (succinyl-CoA) during aerobic and anaerobic growth on glucose. Only strains combining a deficiency in 2-oxoglutarate dehydrogenase with the presence of an active succinate dehydrogenase required succinate for aerobic growth. In all mutants, including the triple mutant (frd sucA aceA), the succinate requirement was suppressed by inactivating succinate dehydrogenase. The aerobic growth rates of succinate-independent strains were most affected by lack of isocitrate lyase but only two mutants (sdh sucA aceA and frd sdh sucA aceA) grew faster with added succinate: the growth yields were lowered by deficiencies in isocitrate lyase and also succinate dehydrogenase. It is concluded that very little succinate is needed for biosynthesis during aerobic growth on glucose and the requirement for relatively high concentrations of succinate (2 mM) by mutants lacking 2-oxoglutarate dehydrogenase or related functions stems from the presence of active succinate dehydrogenase. Anaerobically, either isocitrate lyase or fumarate reductase is essential for succinate-independent growth on glucose.
...
PMID:Succinate dehydrogenase-dependent nutritional requirement for succinate in mutants of Escherichia coli K12. 36 70

Spectrophotometric and fluorimetric substrate couple titrations and potentiometric spectrophotometric titrations were used to determine the oxidation-reduction potentials of components showing absorbance or fluorescence at the wavelengths attributable to the flavoproteins of mitochondria fractionated using digitonin together with sonication. A pure mitoplast fraction devoid of cytochrome b5 contamination could be obtained using 230 micrograms digitonin/mg of mitochondrial protein. The digitonin-soluble fraction contained a species having Em7.4 = -123 mV and probably represents the outer membrane flavoproteins. The inner membrane-matrix fraction, treated with ultrasound, provided evidence of a flavoprotein species with redox potential (Em7.4 = -302 mV) in the matrix fraction. The -302 mV component is probably lipoamide dehydrogenase. A high redox potential species with Em7.4 = +19 mV in titrations with the succinate fumarate couple was located in the inner membrane vesicles and is probably identical with succinate dehydrogenase. The electron-transferring flavoprotein (ETF) was isolated from bovine heart mitochondria and its Em7.4 = -74 mV determined. The component in the matrix fraction with an apparent Em7.4 = -56 mV probably represents ETF, and that in the inner membrane fraction with an apparent Em7.4 = -43 mV the NADH dehydrogenase flavoprotein. A component in an apparently low concentration with Em7.4 = +30 mV was detected in the inner membrane fraction. This probably represents the ETF-dehydrogenase flavoprotein. The origin of the flavoprotein fluorescence of mitochondria and intact tissues is discussed.
...
PMID:Oxidation-reduction midpoint potentials of mitochondrial flavoproteins and their intramitochondrial localization. 55 61

Triamcinoline acetonide (10 mg per kg of body weight a day) was administered to rabbit fed on a laboratory chow diet. The content of flavins in liver but not in kidney, muscle and brain started to decrease 24 h after a single dose. The activities of enzymes in the liver were determined: the activities of pyruvate dehydrogenase complex, lipoamide dehydrogenase (NADH:lipoamide oxidoreductase EC 1.6.4.3), NADH dehydrogenase (NADH : (acceptor) oxidoreductase EC 1.6.99.3) and D-amino acid oxidase (D-amino acid: oxygen oxidoreductase (deaminating) EC 1.4.3.3) were decreased but those of succinate dehydrogenase (succinate : (acceptor) oxidoreductase EC 1.3.99.1) and xanthine oxidase (xanthine : oxygen oxidoreductase EC 1.2.3.2) remained unchanged. The activities of enzymes in the kidney, however, remained unchanged except the decrease in the activity of pyruvate dehydrogenase complex.
...
PMID:Effect of triamcinolone administration on content of flavins in rabbit liver. 127 76

The fluorescence signal of flavoproteins of rat liver mitochondria was investigated to determine the respective contributions of the various flavoenzymes. About 50% of the overall signal were found to be NAD-linked and caused by alpha-lipoamide dehydrogenase flavin (Em7.4 = -283 mV). Roughly 25% were due to a flavoprotein reducible in a non-NAD-linked reaction. This fluorescent flavoenzyme (Em7.4 = -52 mV) has been tentatively identified as a flavoprotein of the fatty-acid-oxidizing system, most probably the electron transfer flavoprotein. The remaining 25% of the signal are accounted for by flavoenzymes which are reducible by dithionite only. These flavoenzymes were not involved in the flavoprotein fluorescence alterations accompanying changes in electron flow through the respiratory chain. Contributions of other mitochondrial flavoproteins such as succinate dehydrogenase, NADH dehydrogenase, alpha-glycerophosphate dehydrogenase, proline dehydrogenase, and choline oxidase, to the overall flavin fluorescence signal of isolated rat liver mitochondria can be neglected.
...
PMID:Contribution of different enzymes to flavoprotein fluorescence of isolated rat liver mitochondria. 402 66

1. A spectroscopic resolution has been made of the components contributing to the ;iron-flavoprotein' trough extending from 450 to 520nm in the reduced-minus-oxidized difference spectrum of submitochondrial particles of Torulopsis utilis. 2. Seven components were identified other than cytochrome b, ubiquinone and succinate dehydrogenase. On the basis of the effects of iron- and sulphate-limited growth of cells on their subsequently derived electron-transport particles, and also by consideration of analytical measurements of the concentration of FMN, FAD, non-haem iron and acid-labile sulphide in the electron-transport particles in relation to the magnitude of the spectroscopic changes, it was possible to identify five of these components as follows: species 1a, the flavin of NADH dehydrogenase ferroflavoprotein; species 1b, the iron-sulphur component of NADH dehydrogenase ferroflavoprotein; species 1', the flavin of an NADPH dehydrogenase; species 2, an iron-sulphur or ferroflavoprotein component; species 3, the flavin of l-3-glycerophosphate dehydrogenase. Two additional components were a fluorescent flavoprotein, probably lipoamide dehydrogenase, and a b-type cytochrome reducible by NADH or NADPH but not reoxidizable by the respiratory chain. 3. Species 1b and 2 were undetectable in electron-transport particles from iron- or sulphate-limited cells, but could be recovered in vivo under non-growing conditions. 4. The recovery in vivo of species 2 but not species 1b was inhibited by cycloheximide. 5. The recovery of species 1b correlates with the recovery of site 1 conservation. 6. The recovery of species 1b with species 2 correlates with the recovery of piericidin A sensitivity. 7. Evidence is presented for an NADPH dehydrogenase distinct from NADH dehydrogenase. The oxidation of NADH and NADPH by the respiratory chain is sensitive to piericidin A, and an iron-sulphur protein common to both pathways (species 2) is suggested as the piericidin A-sensitive component. 8. The approximate E'(0) (pH7.0) values of species 1 (a and b, low potential) and species 2 (high potential) indicate that site 1 energy conservation occurs between the levels of species 1 (a and b) and species 2.
...
PMID:Spectroscopic studies of flavoproteins and non-haem iron proteins of submitochondrial particles of Torulopsis utilis modified by iron- and sulphate-limited growth in continuous culture. 439 18

Treatment of rat liver mitochondria with digitonin followed by differential centrifugation was used to resolve the intramitochondrial localization of both soluble and particulate enzymes. Rat liver mitochondria were separated into three fractions: inner membrane plus matrix, outer membrane, and a soluble fraction containing enzymes localized between the membranes plus some solublized outer membrane. Monoamine oxidase, kynurenine hydroxylase, and rotenone-insensitive NADH-cytochrome c reductase were found primarily in the outer membrane fraction. Succinate-cytochrome c reductase, succinate dehydrogenase, cytochrome oxidase, beta-hydroxybutyrate dehydrogenase, alpha-ketoglutarate dehydrogenase, lipoamide dehydrogenase, NAD- and NADH-isocitrate dehydrogenase, glutamate dehydrogenase, aspartate aminotransferase, and ornithine transcarbamoylase were found in the inner membrane-matrix fraction. Nucleoside diphosphokinase was found in both the outer membrane and soluble fractions; this suggests a dual localization. Adenylate kinase was found entirely in the soluble fraction and was released at a lower digitonin concentration than was the outer membrane; this suggests that this enzyme is localized between the two membranes. The inner membrane-matrix fraction was separated into inner membrane and matrix by treatment with the nonionic detergent Lubrol, and this separation was used as a basis for calculating the relative protein content of the mitochondrial components. The inner membrane-matrix fraction retained a high degree of morphological and biochemical integrity and exhibited a high respiratory rate and respiratory control when assayed in a sucrose-mannitol medium containing EDTA.
...
PMID:Enzymatic properties of the inner and outer membranes of rat liver mitochondria. 569 70

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.
...
PMID:Characteristics of mitochondria isolated by rate zonal centrifugation from normal liver and Novikoff hepatomas. 624 94

To differentiate the effect of muscle contractile activity from that of motor nerve on oxidative processes in type I muscle, oxidative processes were studied in muscle after immobilization and after denervation. The two processes led to similar atrophy of muscle weight and of the mean diameter of muscle fibers. Disuse of soleus muscle (type I) did not affect rates of oxidation of 14C-labeled substrates although these were reduced by disuse of the vastus lateralis (type II). Disuse of the soleus did not affect activities of several mitochondrial enzymes assayed by histochemical or biochemical methods. However, denervation of the soleus did lead to a fall in metabolic rates and enzyme activities. The activity of 3-hydroxybutyrate dehydrogenase fell more than did the activities of succinic dehydrogenase, lipoamide dehydrogenase, or cytochrome-c oxidase in both homogenates and in mitochondrial fractions. These results suggest nerve may regulate mitochondrial enzymes in type I muscle. The mechanism appears to be different from that which regulates oxidative processes in type II muscle.
...
PMID:Effects of denervation and simple disuse on rates of oxidation and on activities of four mitochondrial enzymes in type I muscle. 625

NADH:ubiquinone reductase (complex I) of the mitochondrial inner membrane respiratory chain binds a number of mitochondrial matrix NAD-linked dehydrogenases. These include pyruvate dehydrogenase complex, alpha-ketoglutarate dehydrogenase complex, mitochondrial malate dehydrogenase, and beta-hydroxyacyl-CoA dehydrogenase. No binding was detected between complex I and cytosolic malate dehydrogenase, glutamate dehydrogenase, NAD-isocitrate dehydrogenase, lipoamide dehydrogenase, citrate synthase, or fumarase. The dehydrogenases that bound to complex I did not bind to a preparation of complex II and III, nor did they bind to liposomes. The binding of pyruvate dehydrogenase complex, alpha-ketoglutarate dehydrogenase complex, and mitochondrial malate dehydrogenase to complex I is a saturable process. Based upon the amount of binding observed in these in vitro studies, there is enough inner membrane present in the mitochondria to bind the dehydrogenases in the matrix space. The possible metabolic significance of these interactions is discussed.
...
PMID:Complex I binds several mitochondrial NAD-coupled dehydrogenases. 643 16


1 2 Next >>

---