Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.99.5 (NADH dehydrogenase)
 2,135 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A nondenaturing gradient polyacrylamide gel electrophoresis method is described for the resolution of membrane proteins. Bovine heart inner mitochondrial membranes were solubilized in Triton X-100 and individual complexes were identified by staining for activity and protein. Succinate dehydrogenase was isolated by band excision and shown by electrophoresis under denaturing conditions to be highly purified. In addition, the electrophoretic transfer of NADH dehydrogenase to nitrocellulose was demonstrated. The enzyme was identified on the resulting blot by activity staining and the binding of monospecific antibodies.
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PMID:Purification and analysis of mitochondrial membrane proteins on nondenaturing gradient polyacrylamide gels. 370 6

Membranes isolated from Bacillus cereus ATCC 4342 during vegetative growth and during sporulation contained cytochromes b, c and a + a(3) as well as flavoprotein as determined from reduced-minus-oxidized difference spectra. Although there appeared to be no qualitative change in the cytochromes, there was a significant increase in the amount of cytochromes associated with membranes isolated from sporulating cells. Succinate and nicotinamide adenine dinucleotide (reduced form) (NADH) reduced the same cytochromes indicating similar pathways of electron transport. The electron transport inhibitors-cyanide, azide, 2-heptyl-4-hydroxyquinoline-N-oxide, dicumarol and atebrine-were examined for their effect on succinate oxidase (succinate: [O(2)] oxidoreductase) and NADH oxidase (NADH: [O(2)] oxidoreductase). NADH oxidase associated with vegetative cell membranes was less sensitive to certain inhibitors than was succinate oxidase, suggesting a branched electron transport pathway for NADH oxidation. In addition to electrons being passed to O(2) through a quinone-cytochrome chain, it appears that these intermediate carriers can be bypassed such that O(2) is reduced by electrons mediated by NADH dehydrogenase. Both oxidases associated with sporulating cell membranes were inhibited to a lesser degree than were the oxidases associated with vegetative cell membranes.
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PMID:Electron transport system associated with membranes of Bacillus cereus during vegetative growth and sporulation. 412 46

This paper describes experiments conducted with membranous and soluble fractions obtained from Escherichia coli that had been grown on succinate, malate, or enriched glucose media. Oxidase and dehydrogenase activities were studied with the following substrates: nicotinamide adenine dinucleotide, reduced form (NADH), nicotinamide adenine dinucleotide phosphate, reduced form (NADPH), succinate, malate, isocitrate, glutamate, pyruvate, and alpha-ketoglutarate. Respiration was virtually insensitive to poisons that are commonly used to inhibit mitochondrial systems, namely, rotenone, antimycin, and azide. Succinate dehydrogenase and NADH, NADPH, and succinate oxidases were primarily membrane-bound whereas malate, isocitrate, and NADH dehydrogenases were predominantly soluble. It was observed that E. coli malate dehydrogenase could be assayed with the dye 2,6-dichlorophenol indophenol, but that porcine malate dehydrogenase activity could not be assayed, even in the presence of E. coli extracts. The characteristics of E. coli NADH dehydrogenase were shown to be markedly different from those of a mammalian enzyme. The enzyme activities for oxidation of Krebs cycle intermediates (malate, succinate, isocitrate) did not appear to be under coordinate genetic control.
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PMID:Respiration and protein synthesis in Escherichia coli membrane-envelope fragments. I. Oxidative activities with soluble substrates. 430 12

Spheroplast membranes (spheroplast envelopes) of strain 2091 of group B Neisseria meningitidis were prepared by a procedure that included lysozyme treatment of the cells and osmotic lysis of the resulting spheroplasts. Electron microscopy revealed that the membranes consisted of two unit layers, generally parallel to each other. The membrane preparation migrated as a single component in a 40 to 70% sucrose gradient and consisted of 62% protein, 28% lipid, 9% ribonucleic acid, small amounts of carbohydrate, hexosamine, and deoxyribonucleic acid. When 1 or 10 mug (dry weight) was injected intravenously into rabbits, a mild pyrogenic reaction was elicited. In immunodiffusion tests, immune rabbit serum prepared against spheroplast membranes produced three major precipitin lines, with the homologous antigen solubilized with sodium dodecyl sulfate, and a single line with untreated antigen. The immune serum also reacted with a cell wall antigen, and to a lesser extent with some of the cytoplasmic antigens. Succinate dehydrogenase and reduced nicotinamide adenine dinucleotide (NADH) oxidase activities were found to be associated with the spheroplast membranes. NADH dehydrogenase also was associated with the membranes but was gradually released and recovered in other fractions. Glutamate-oxaloacetate transaminase, glutamate, glucose-6-phosphate, and isocitrate dehydrogenase activities were not found in the membrane preparation. About one-third of these enzymatic activities were recovered in the supernatant fluid after the sedimentation of the spheroplasts and two-thirds were recovered in the cytoplasmic fraction. N-acetylneuraminic acid (NAN)-condensing enzyme and cytidine monophosphate-NAN synthesizing enzyme also were identified in this organism. These enzymes were not associated with the membranes and were recovered from extracts from whole cells, spheroplasts, or cells exposed to osmotic shock, as well as from spheroplast supernatant and shock fluids. It is concluded that the spheroplast membranes of the strain of meningococci used in these studies are typical of those recovered from gram-negative bacteria.
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PMID:Characterization of spheroplast membranes of Neisseria meningitidis group B. 463 Jul 22

It was shown that malate dehydrogenase of isolated membranes of the gramicidin S producer Bacillus brevis var. G.-B. (R.-form) is completely inhibited by the antibiotic (approximately 200 mkg/mg of protein). Succinate and NADH dehydrogenases at concentration up to 1 mg per mg of protein are insensitive to it, while corresponding oxidases are inhibited by the antibiotic not more than by 65 -- 75% apparently due to partial damage of the terminal parts of the respiratory chain. The respiration of the producer intact cells is inhibited by exogenous gramicidin S by not more than 55 -- 60%, while the respiration of antibiotic-sensitive cells of M.lysodeikticus is inhibited completely. It was shown that phosphatidyl ethanolamine (50%), phosphatidyl glycerol (15% and diphosphatidyl glycerol (25%) are the major phospholipid components of the membranes of the given strain of Bac. brevis. It was assumed that the resistance of Bac. brevis cells to gramicidin S is partly due to the constant ratio of the charged and amphoteric phospholipids. Using 31P-NMR spectroscopy, the kinetics of free phosphoric compounds in the cells and cell extracts of Bac. brevis during culture growth and gramicidin S synthesis were studied. The content of carbohydrate monophosphate, remained unaffected, while that of nucleoside di- and triphosphates and dinucleotides was low and at definite density and gramicidin S content (above 100 mkg/ml) fell down below the resolution capacity of the method employed. Evidence for gramicidin S localization of the Bac. brevis membrane and possible causes for the manifestation of the NADH dehydrogenase activity at a certain stage of culture growth are discussed.
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PMID:[Localization of gramicidin S on the cytoplasmic membrane of Bacillus brevis and its effect on the activity of membrane enzymes]. 616 75

It is shown that the Notch8 deficiency in Drosophila melanogaster affects a number of enzyme activities localized in the mitochondria, such as NADH oxidase (activity of the complete respiratory chain), NADH dehydrogenase (the first step in the respiratory chain before transfer to ubiquinone), Succinate dehydrogenase and alpha-glycerophosphate dehydrogenase. The experiments reported here do not exclude the possibility of involvement of other genes in the deficiency. The effect of duplications of the Notch locus on NADH oxidase and NADH dehydrogenase suggest that the locus determines the enzyme activities. The dosage effects of the Notch locus on activity suggest that this locus contains the structural genes for these enzymes.
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PMID:The action of the notch locus in Drosophila melanogaster. I. Effects of the notch8 deficiency on mitochondrial enzymes. 679 Sep 11

Membrane-bound antigens of the respiratory chain of Micrococcus luteus were analyzed by crossed immunoelectrophoresis after growth of the organism in the presence of 59Fe, the flavin adenine dinucleotide-flavin mononucleotide precursor D-[2-14C]riboflavin, or the heme precursor 5-amino-[4-(14)C]levulinic acid. Using zymograms and procedures of selective extraction in conjunction with autoradiography, it was possible to resolve and partially characterize a number of antigens. Succinate dehydrogenase (EC 1.3.99.1) was shown to possess covalently bound flavin and nonheme iron and was possibly present as a complex with cytochrome. Three other dehydrogenases, namely, NADH dehydrogenase, NAD(P)H dehydrogenase (EC 1.6.99.3), and malate dehydrogenase (EC 1.1.1.37), contained flavin in noncovalent linkage, the NAD(P)H dehydrogenase also possessing nonheme iron. Four other discrete antigens (or antigen complexes) containing both iron and heme centers also resolved, as were two minor immunogens possessing iron as the sole detectable prosthetic group.
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PMID:Immunochemical analysis of respiratory-chain components of micrococcus luteus (lysodeikticus). 684 87

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

In Ascaris muscle mitochondria the major respiratory chain-linked phosphorylation activity is accomplished by a NADH-linked reduction of fumarate to succinate. Oxygen can also be employed as a terminal electron acceptor via a cyanide- and salicyl-hydroxamate-resistant terminal oxidase. As in fumarate-dependent electron transport this process appears to be coupled to energy conservation at phosphorylation site I. The branchpoint from which electrons are taken from the main respiratory chain to either the alternative oxidase or fumarate reductase is likely to be on the oxygen side of the NADH dehydrogenase segment. Malate and succinate are the only substrates which appreciably support respiration in the mitochondrion of the nematode. Regardless of the presence or absence of oxygen malate is utilized by an oxidation-reduction reaction resulting in the formation of pyruvate, acetate, succinate, propionate and CO2. In addition, aerobically, hydrogen peroxide is formed as the product of oxygen reduction. Succinate accumulation was found to be significantly higher in the anaerobic as compared to the aerobic incubation mixtures. This effect was accompanied by an increase in anaerobic malate consumption. ATP generation and the formation of pyruvate, acetate and propionate were found to be similar in the presence and absence of oxygen. In malate-supported respiration of intact Ascaris mitochondria reducing equivalents (NADH) are produced exclusively through pyruvate and acetate formation. These enzymatic reactions are functionally coupled to the electron transport-linked reductions of fumarate to succinate and oxygen to hydrogen peroxide, respectively. In accordance with the position of the redox potentials of the fumarate/succinate and O2/H2O2 couples, anaerobic and aerobic respiration was found to be associated with relatively low energy conservation efficiencies. Thus one molecule of ATP was conserved per 2e- transferred to fumarate or oxygen, respectively. No evidence could be obtained for a significant activity of energy conservation sites II and III and electron transfer through the alternative oxidase pathway was shown not to be coupled to phosphorylation.
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PMID:Mechanisms of respiration and phosphorylation in Ascaris muscle mitochondria. 744 10

Effect of the polycation on oxidative phosphorylation in the rat liver mitochondria has been studied. Both oxygen uptake and coupled phosphorylation were progressively inhibited by increasing concentration of the polycation, as observed with NAD-linked substrates, succinate and ascorbate+TMPD which activates the terminal part of the respiratory chain. NADH oxidase, NADH dehydrogenase and cytochrome oxidase were strongly inhibited by the polycation, 80-90% of the activity being lost at an inhibitor concentration of 100 microM. Succinate oxidase and succinate dehydrogenase were inhibited 60-66% at 100 microM concentration of the polycation. The polycation inhibited the uncoupler 2,4-dinitrophenol stimulated ATPase activity both in presence and absence of Mg2+ ions. The polycation also inhibited salt-induced volume change.
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PMID:Inhibition of mitochondrial oxidative phosphorylation and its electron transport pathway by a polycation in vitro. 850 25


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