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)

A succinic dehydrogenase (SDH) complex has been purified from Triton X-100-solubilized membranes from Bacillus subtilis by precipitation with specific antibody. Radioactively labeled precipitated complex was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography of the gels. The complex contained equimolar amounts of three polypeptides with approximate molecular weights of 65,000, 28,000, and 19,000. Five succinic dehydrogenase-negative mutants, belonging to the citF group, contained the 65,000-dalton polypeptide in a soluble form in the cytoplasm. Each 65,000-dalton polypeptide had about one molecule of flavin bound. Another citF mutant, citF11, which lacks the 65,000-dalton polypeptide, contained a membrane-bound 28,000-dalton polypeptide. The wild-type succinic dehydrogenase complex contained cytochrome, probably a cytochrome b. The 19,000-dalton polypeptide is suggested to represent the apoprotein of this cytochrome. The 65,000-dalton and the 28,000-dalton polypeptides are thought to constitute succinic dehydrogenase and to correspond to the flavoprotein and the ironprotein, respectively, as described for succinic dehydrogenase isolated from beef heart mitochondria or Rhodospirillum rubrum chromatophores. The results presented suggest that in B. subtilis succinic dehydrogenase is attached to a cytochrome b in the membrane via the 28,000-dalton (ironprotein) polypeptide.
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PMID:Characterization of a succinate dehydrogenase complex solubilized from the cytoplasmic membrane of Bacillus subtilis with the nonionic detergent Triton X-100. 10 58

A 5-aminolevulinic acid-requiring mutant of Bacillus subtilis was isolated. When the mutant is shifted from medium containing 5-aminolevulinic acid to medium lacking this growth factor, the bacteria continued to grow at undiminished rate for about three generations. The membranes from these bacteria contained severely reduced amounts of cytochrome. The mutant was used to study the role of heme synthesis on synthesis and membrane binding of succinic dehydrogenase (SDH). The amount of SDH in whole-cell lysates in the soluble cytoplasmic fraction and in membranes was determined by one-dimensional (rocket) immunoelectrophoresis with an SDH-specific antiserum. After heme synthesis was blocked, the relative amount of SDH in the membrane decreased, whereas increasing amounts of SDH antigen were found in the cytoplasm. When heme synthesis was resumed on readdition of 5-aminolevulinic acid, the amount of membrane-bound SDH antigen increased at a much faster rate than net synthesis. During a 3-h growth period without 5-aminolevulinic acid, there was little change in the pattern of membrane proteins as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of radioactively labeled membranes, as compared to membranes from control cultures. However, both the 65,000-dalton and the 28,000-dalton polypeptides of the SDH complex (L. Hederstedt, E. Holmgren, and L. Rutberg, J. Bacteriol. 138:370-376, 1979) were present in decreasing amounts in membranes from 5-aminolevulinic acid-starved bacteria. From these results we suggest that SDH in B. subtilis is synthesized as a soluble protein and becomes membrane bound only when it attaches to a site in the membrane, (part of) which is a cytochrome of b type.
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PMID:Role of heme in synthesis and membrane binding of succinic dehydrogenase in Bacillus subtilis. 10 59

In addition to the two species of ferredoxin-type iron-sulfur centers (Centers S-1 and S-2), a third iron-sulfur center (Center S-3), which is paramagnetic in the oxidezed state analogous to the bacterial high potential iron-sulfur protein, has bwen detected in the reconstitutively active soluble succinate dehydrogenase preparation. Midpoint potential (at pH 7.4) of Center S-3 determined in a particulate succinate-cytochrome c reductase is +60 +/- 15 mV. In soluble form, Center S-3 becomes extremely labile towards oxygen or ferricyanide plus phenazine methosulfate similar to reconstitutive activity of the dehydrogenase. Thus, even freshly prepared reconstitutively active enzyme preparations show EPR spectra of Center S-3 which correspond approximately to 0.5 eq per flavin; in particulate preparations this component was found in a 1:1 ratio to flavin. All reconstitutively inactive dehydrogenase preparations that Center S-3 is an innate constituent of succinate dehydrogenase and plays an important role in mediating electrons from the flavoprotein subunit to most probably ubiquinone and then to the cytochrome chain.
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PMID:Thermodynamic and EPR characteristics of a HiPIP-type iron-sulfur center in the succinate dehydrogenase of the respiratory chain. 17 56

Polarographic studies on oxidation-reduction components bound with chromatophores from Rhodospirillum rubrum were carried out at 24 degrees. 1. Using a carbon-paste electrode as the working electrode, polarographic waves characteristic of oxidation-reduction components were observed in the presence, but not in the absence of Triton X-100; these waves were therefore measured in the presence of the detergent. 2. At least two kinds of oxidation-reduction components were detectable, having different half-wave potentials (E1/2); at pH 7, one had an E1/2 value of +275 mV (POC+275) and the other had a value of +60 mV (POC+60). 3. POC+275 was reduced by succinate and by NADH. Both reductions were almost completely inhibited by antimycin A, which hardly affected the reductions of ubiquinone-10 by succinate and by NADH. Most POC+275 molecules were not reduced by the substrates when quinones were extracted from the chromatophores, and the reductions were mostly restored when ubiquinone-10 was re-added. This indicates that POC+275 is functional between ubiquinone-10 and cytochrome c2 in the electron transport system. 4. POC+60 was reduced by succinate, but hardly at all by NADH. The reduction of POC+60 was not influenced either by the addition of antimycin A or by the extraction of quinones. This suggests that POC+60 is functional in the process from succinate dehydrogenase [EC 1.3.99.1] to ubiquinone-10 in the electron transport system. 5. Of the POC+275 reducible by dithionite, approximately 70% could be reduced in the absence of Triton X-100, provided that the potential of the working electrode immersed in chromatophore suspensions was set at potentials of 0 mV or lower and that the electrochemical reaction was carried out at pH 7.5. When the potential of the electrode was set at +50 mV (the same as the E1/2 value of ubiquinone-10 bound with chromatophores), and the suspension was allowed to stand for various lengths in the presence of the detergent, it was found that approximately half of the electrochemically reducible POC+275 was rapidly reduced, followed by a slow reduction. The discrepancy in the oxidation-reduction equilibrium on the basis of the E1/2 values of ubiquinone-10 and POC+275 is discussed.
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PMID:Polarographic studies in presence of Triton X-100 on oxidation-reduction components bound with chromatophores from Rhodospirillum rubrum. 18 68

Activities of succinate dehydrogenase, succinate- and NAD-H-cytochrome c--reductases, and cytochrome c--oxidase was compared in 1 g tissue homogenate and homogenate fractions made from 1 g brain tissue using various solutions. Fractionation resulted in the increased activities of NADH- and succinate cytochrome reductases, and in the loss of succinate dehydrogenase activity, cytochrome oxidase was less influenced. These phenomena are regarded as signs of the interrelation between mitochondria and other constituents of brain cell within homogenates. Maximal quantity of mitochondria isolated from homogenates is no more than 20% of all the mitochondrial homogenates (according enzyme data). The electronogram of the brain mitochondrial preparation isolated in the Krebs--Ringer solution without glucose pointed out to a high homogeneity of mitochondria in the residue.
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PMID:[Enzyme, electron microscopic and polarographic characteristics of isolated rat brain mitochondria. III. Quantitative assessment of their distribution in fractions of the homogenate]. 18 80

Laboratory animals were kept for 2, 8 and 16 hours in a pressure chamber, the air of which contained 8% O2 and 92% N2. Histochemical and ultrastructural examinations revealed the following duodenal alterations: 1. The alkaline phosphatase activity of the epithelium and glandular epithelium showed no alteration; the acid phosphatase activity was slightly increased in hypoxia. 2. The succinic dehydrogenase and cytochrome C oxidase activities of the glandular epithelium showed a marked decrease. 3. Two hours of hypoxia led to destruction of the microvillous epithelium. Prolonged hypoxia resulted in the destruction of the microvilli as well as of the cuticula. 4. Hypoxia of short duration had no damaging effect on glandular epithelial cells. After 8 to 16 hours of hypoxia, glandular secretion was reduced and the epithelial cells were evacuated. From the findings of the present investigation it is concluded that the decrease in the production of protective intestinal juice, due to the damaging effect of hypoxia on the epithelium and glandular epithelium as well as on the mitochondria, and the increase in the absorption of the intestinal content should be considered responsible of the additional damages to the intestinal epithelium.
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PMID:Histochemical and ultrastructural alterations of the duodenum in acute hypoxia. 18 69

A new simple method for the purification of the bc1-complex has been developed. The polypeptide composition of the complex was analysed by dodecyl sulfate-polyacrylamide gel electrophoresis. The content of chain components and phospholipids was determined. The b-type cytochromes were further characterized by their absorbance spectra and midpoint potentials. (1) Starting from a Triton X-100 extract of submitochondrial particles supplemented with antimycin, the bc1-complex is purified by adsorption chromatography on hydroxyapatite with citrate as specific eluant. (2) The complex splits in dodecyl sulfate into five main polypeptides with apparent molecular weight of 47, 44, 31, 11 and less than 10 kdalton. (3) The purified complex has a heme-b content of 8.0 mumol/g protein and a cytochrome c1 content of 3.8 mumol/g protein. (4) The cytochromes show the typical absorbance spectra of cytochromes b-562 and b-565 and are present in approximately equal amounts with midpoint potentials of Em7 = + 100 mV and Em7 = + mV respectively. Carbon monoxide does not bind to the cytochromes. (5) The nonheme iron protein content of the complex is diminished to 0.6 mumol/g protein. (6) The use of the nonionic surfactant Triton X-100 leads to a complete loss of lipids and ubiquinone of the bc1-complex. (7) The complex contains no succinate dehydrogenase as indicated by the absence of the 69 kdalton subunit in the dodecyl sulfate gel electrophoresis. In addition, it lacks an ubiquinone cytochrome c reductase activity and other electron transferring activities. This may be inferred from an inhibition by antimycin and depletion of ubiquinone and phospholipids. The highly purified and relative stable complex can be prepared giving 50% yield and may be suitable for protein chemistry studies.
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PMID:bc1-Complex from beef heart. One-step purification by hydroxyapatite chromatography in Triton X-100, polypeptide pattern and respiratory chain characteristics. 18 10

One hour after a single i.v. dose of 250 mg/kg folic acid, the straight portion of distal tubules in the outer medulla of rat kidneys showed a distinct reduction in succinate dehydrogenase, NADH2-diaphorase, glutamate dehydrogenase, cytochrome oxydase, Na+/K+-ATPase, and acid phosphatase activity. In contrast, the proximal tubules exhibited only a reduction in glutamate dehydrogenase and alkaline phosphatase activity. At this time the straight portion of the distal tubules, whose enzyme activity had changed, showed partly regressive epithelial changes. 24 hours after folic acid administration an even greater reduction in enzyme activity had occurred in the straight portion of distal tubules; these structures also became dilated. The adjacent collecting tubules and the corresponding proximal tubules were also severely dilated, the proximal tubules showing a loss in enzyme acitivities similar to those observed in the distal tubules. 48 hours after folic acid administration the changes largely resembled those observed after 24 hours, but were more pronounced. At this time a tubular regeneration was observed. 72 hours after folic administration extensive normalization of the histological and histochemical changes had occured. It is postulated that a disturbance of the hairpin counter-current mechanism occurs as a result of a direct, concentration-dependent effect of folic acid on the enzymes of the energy supplying metabolism. A dilation in the region of the loop of Henle and the collecting tubules occurs subsequently.
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PMID:Enzyme histochemistry of rat folic acid nephropathy. 19 86

A CO-binding hemochrome was accumulated in Escherichia coli cells, when intracellular heme concentration was increased by aerobic incubation of resting cell suspensions with ALA. Reduced minus oxidized difference spectrum of the hemochrome showed peaks at 560, 530, and 430 nm and a shoulder at 575 nm. The peaks of CO reduced minus reduced difference spectrum were located at 572, 540, and 422 nm. The CO spectrum was similar to but not identical with the spectrum of cytochrome o, a known terminal oxidase in E. coli. SDS-polyacrylamide gel electrophoresis of the CO-binding hemochrome showed its molecular weight to be about 33,000. The hemochrome in crude cell-free extracts was oxidized by aeration and reduced by the addition of succinate or NADH. The reduction by succinate was inhibited by inhibitors of succinate dehydrogenase [EC 1.3.99.1], and the reduction by NADH was inhibited by 2-heptyl-4-hydroxy-quinolin-N-oxide, which is an inhibitor of electron transport in E. coli cells.
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PMID:A carbon monoxide-binding hemoprotein formed by heme accumulation in Escherichia coli. 19 71

In 175 dogs myocardial infarction was produced by high ligation of descending branch of left coronary artery. At various intervals after the intervention (1, 3, 5, 10, 30, 180 days), the activities and levels of NAD, NADH, FAD, riboflavin, cytochrome C, myoglobin, some NAD-dependent Krebs cycle enzymes, and mitochondrial succinate dehydrogenase and cytochrome oxidase were determined in the infarcted zone. It was found that in the infarcted zone there occurred substantial disturbances of various links constituting the tissue oxidative chain, in the stages of substrate dehydrogenation, electron transport to oxygen molecule, and myocardial oxygen uptake. The greatest disturbances took place in the systems of NAD and NAD-dependent enzymes, whereas the succinate oxidation system sustained substantially lesser damage. The decrease inlevels of flavonoids, which was likewise observed, participated also in the mechanism inhibiting succinate dehydrogenase. The cytochrome system activity was limited by the level of cytochrome C, whose deep decrease persisted considerably long in the infarcted zone. A certain role in disturbances of oxidative processes may have been played by the decreased concentration of myoglobin, an important myocardial reservoir of oxygen.
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PMID:Some myocardial factors of biological oxidation in experimental myocardial infarction. 19 79


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