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:1.6.99.5 (NADH dehydrogenase)
2,135 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The locus of inhibition of nicotinamide adenine dinucleotide, reduced form (NADH) oxidation in mitochondria by rotenone, piercidin A, and barbiturates is considered in the light of available information. Most lines of evidence indicate that the point of inhibition is on the O(2) side of NADH dehydrogenase. Kinetic experiments on the substrate-induced appearance of the electron paramagnetic resonance signal at g = 1.94 in membrane preparations (ETP) reveal that these inhibitors do not interfere with the reduction of the electron paramagnetic resonance detectable iron by NADH. Our spectrophotometric studies on complex I give no evidence for absorbance differences between untreated and rotenone or piericidin inhibited preparations, which can be attributed to nonheme iron. Whatever changes were observed appear to be due to cytochromes. These experiments, therefore, do not support the idea that in inhibited preparations electron transport is interrupted between the flavin and nonheme iron components of NADH dehydrogenase. The specific binding of rotenone and piericidin seems to involve both lipid and protein. The possibility that NADH dehydrogenase participates in the binding is suggested by the apparent stoichiometric relation between specific binding site titer and NADH dehydrogenase content and the profound effect of mersalyl inhibition of the enzyme on piericidin binding capacity.ETP, electron transport particle.
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PMID:Reaction sites of rotenone, piericidin A, and amytal in relation to the nonheme iron components of NADH dehydrogenase. 431 16

The sensitivity of nicotinamide adenine dinucleotide (NADH) oxidase and succinoxidase to metal chelators, the generation of an electron paramagnetic resonance (EPR) signal upon addition of these substrates, and the rate of formation of the EPR signal relative to the rate of the cytochrome reduction suggest the participation of nonheme iron proteins in the respiratory process of Escherichia coli. The most inhibitory metal chelator, thenoyltrifluoro acetone, inhibited the reduction of nonheme iron and cytochromes but did not prevent the reoxidation of the reduced forms. The EPR signal, dehydrogenase, and oxidase activities evoked by NADH are considerably greater than the corresponding activities evoked by succinate. Because both substrates can reduce almost all of the cytochromes, a model in which fewer succinate dehydrogenase-nonheme iron protein complexes are linked to a common cytochrome chain than NADH dehydrogenase-nonheme iron protein complexes is considered likely.
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PMID:Respiration and protein synthesis in Escherichia coli membrane-envelope fragments. V. On the reduction of nonheme iron and the cytochromes by nicotinamide adenine dinucleotide and succinate. 433 1

Membrane-envelope fragments have been isolated from Escherichia coli by comparatively mild techniques. The use of DNAase, RNAase, detergents, sonication, lysozyme, and ethylenediaminetetraacetate were avoided in the belief that rather delicate, but metabolically important, associations may exist between the plasma membrane and various cytoplasmic components. The membrane-envelope fragments have been characterized in terms of their content of major chemical components as well as their electron microscope appearance. Fractions containing membrane-envelope fragments were found to possess appreciable DNA- and protein-synthesizing activities. The fragments were rich in membrane content as determined by reduced nicotinamide adenine dinucleotide (NADH) oxidase activity and deficient in soluble components as measured by NADH dehydrogenase activity. The particulate fraction obtained between 20,000 g and 105,000 g and usually considered a ribosomal fraction was rich in membrane content and had a relatively high capacity for DNA synthesis. Envelope fragments sedimenting at 20,000 g attained very high levels of incorporation of amino acids into protein.
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PMID:Respiration and protein synthesis in Escherichia coli membrane-envelope fragments. IV. Chemical and cytological characterization and biosynthetic capabilities of fragments obtained by mild procedures. 433 49

Deoxycholate disruption of Micrococcus lysodeikticus protoplast membranes resulted in solubilization of both l-malate and reduced nicotinamide adenine dinucleotide (NADH) dehydrogenase enzymes (substrate: 2,6-dichlorophenolindophenol oxidoreductases). Insoluble residues contained cytochromes of the b, c, and a type. Solubilized dehydrogenases were reconstituted with insoluble residues by treatment of disrupted membranes with magnesium ions. Most of the solubilized l-malate and NADH dehydrogenase activities were precipitated by magnesium ions independent of enzyme reconstitution with insoluble residues. Reconstituted dehydrogenases explained the mechanism for restoration of disrupted l-malate and NADH oxidase activities (4). Black light irradiation inhibited oxidase activities of both native and reconstituted membranes. These irradiated membrane oxidases were partially restored by exogenous napthoquinones [K(2(20)) and K(2(50))] but not by CoQ((6)). Reconstitution experiments showed that native membrane napthoquinone was retained in the insoluble residues of deoxycholate-disrupted membranes.
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PMID:Reconstitution of Micrococcus lysodeikticus reduced nicotinamide adenine dinucleotide and L-malate dehydrogenases with dehydrogenase-depleted membrane residues: a basis for restoration of oxidase activities. 434 17

Levels of enzymes operative in the Embden-Meyerhof-Parnas (glycolytic) pathway, pentose phosphate cycle, citric acid cycle, and certain other phases of intermediary carbohydrate metabolism have been compared in Thiobacillus thioparus and T. neapolitanus. All enzymes of the glycolytic pathway except phosphofructokinase were demonstrated in both organisms. There were some striking quantitative differences between the two organisms with respect to the activities of the individual enzymes of the glycolytic pathway and the citric acid cycle. Qualitative differences were also found: the isocitrate dehydrogenase activity of T. thioparus is strictly nicotinamide adenine dinucleotide phosphate (NADP)-dependent, whereas that of T. neapolitanus is primarily nicotinamide adenine dinucleotide-dependent, activity with NADP being low; the glucose-6-phosphate dehydrogenase of T. thioparus is particulate, whereas that of T. neapolitanus is partly soluble and partly particulate; the 6-phosphogluconate dehydrogenase of T. thioparus is soluble, that of T. neapolitanus is partly soluble and partly particulate. All enzymes which function in the carbon reduction cycle were present at very high levels. In contrast, enzymes which operate exclusively in cycles other than the carbon reduction cycle were present at low levels. Of the enzymes not operative in the carbon reduction cycle that were examined, isocitric dehydrogenase had the highest specific activity. Both organisms possessed reduced nicotinamide adenine dinucleotide dehydrogenase activity. The qualitative and quantitative aspects of the data are discussed in relation to possible biochemical explanations of obligate autotrophy.
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PMID:Enzymes of intermediary carbohydrate metabolism in the obligate autotrophs Thiobacillus thioparus and Thiobacillus neapolitanus. 439 Sep 65

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

The changes occurring in the respiratory enzymes of anaerobically grown Escherichia coli strain B and E. coli 15 T(-)A(-)U(-)bar during exposure to oxygen were studied. Reduced nicotinamide adenine dinucleotide (NADH) oxidase activity reached its peak soon after O(2) exposure; cytochrome content and succinate oxidase activity increased more slowly, and these increases paralleled each other. The activities of isocitrate and malate dehydrogenases also increased, but the increase was less than that of the succinate and NADH oxidases; exposure to O(2) had no effect on the succinate and NADH dehydrogenase activities. On the other hand, the glycolytic activity decreased slowly after O(2) exposure. The incorporation of (32)P into acid-soluble organic phosphate esters paralleled the respiratory rate during the first 60 min after O(2) exposure, but continued to increase after the respiration reached a plateau. The sensitivity of (32)P incorporation to the uncoupler carbonyl cyanide m-chlorophenylhydrazone also increased with time. The observed relationship between the development of the respiratory chain and the energy-conserving mechanism during O(2) exposure is discussed. Synthesis of the respiratory enzymes upon exposure to oxygen was dependent on concomitant protein and ribonucleic acid synthesis but not on deoxyribonucleic acid synthesis.
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PMID:Induction by oxygen of respiration and phosphorylation of anaerobically grown Escherichia coli. 489 51

This study investigated the effect of the anthracycline antibiotics on oxygen radical metabolism by cardiac mitochondrial reduced nicotinamide adenine dinucleotide (NADH) dehydrogenase [NADH:(acceptor) oxidoreductase, EC 1.6.99.3]. Superoxide formation by NADH dehydrogenase after anthracycline treatment appeared to follow saturation kinetics with an apparent Km of 167.3, 73.3, 64.0, or 47.6 microM for doxorubicin, daunorubicin, rubidazone, or aclacinomycin A, respectively. Superoxide formation by NADH dehydrogenase after doxorubicin treatment occurred with a pH optimum of 7.6 and was accompanied by the production of hydrogen peroxide. Furthermore, drug-related hydroxyl radical generation was detected in this enzyme system by the evolution of methane gas from dimethyl sulfoxide. Hydroxyl radical production proceeded only in the presence of superoxide anion, hydrogen peroxide, and trace amounts of iron or a chelate of iron and ethylenediaminetetraacetate and thus was probably the by-product of a transition metal-catalyzed Haber-Weiss reaction. The antitumor agents mitoxantrone and actinomycin D did not significantly enhance reactive oxygen metabolism by NADH dehydrogenase. These results suggest that the specific activation of the anthracycline antibiotics to free radicals by NADH dehydrogenase leads to the formation of a variety of reactive oxygen species that may contribute to the mitochondrial toxicity of these drugs.
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PMID:Anthracycline antibiotic-stimulated superoxide, hydrogen peroxide, and hydroxyl radical production by NADH dehydrogenase. 630 69

During attempts to clone the gene coding for the respiratory NADH dehydrogenase of Escherichia coli, two hybrid plasmids were constructed from E. coli chromosomal DNA [Young, I. G., Jaworowski, A., & Poulis, M. I. (1978) Gene 4, 25-36]. One of these plasmids, pIY1, derived from EcoRI-digested chromosomal DNA, was studied in detail and shown to possess the gene coding for the NADH dehydrogenase of the aerobic respiratory chain of E. coli. We now report the characterization of the other hybrid plasmid, pIY2, derived from HindIII-digested chromosomal DNA, and shown that it complements ndh mutants not by virtue of carrying the ndh gene but because it carries the gene coding for the respiratory D-lactate dehydrogenase. Cells carrying this hybrid plasmid overproduce the respiratory D-lactate dehydrogenase in their cell membranes by 15-20-fold with negligible activity appearing in the cytoplasm. This results in an amplification of the levels of the D-lactate oxidase. The amplified D-lactate oxidase activity, coupled with the pyridine nucleotide linked D-lactate dehydrogenase, apparently provides a new pathway for the oxidation of reduced nicotinamide adenine dinucleotide (NADH) in the cell, independent of the respiratory NADH oxidase.
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PMID:Cloning of the gene for the respiratory D-lactate dehydrogenase of Escherichia coli. 704 94

Isoniazid (INH) interacts with nicotinamide adenine dinucleotide (NAD+) in the regulation of reduced NAD (NADH) oxidation in electron transport particles from Mycobacterium phlei. the interaction was shown to be at the level of the NADH dehydrogenase by the use of menadione as an artificial electron acceptor. Binding studies indicated that INH and NAD+ did not compete for a common regulatory site. Unlabeled INH was unable to displace [14C]NAD+ from electron transport particles, and unlabeled NAD+ could not remove [3H]INH from particles. Preincubation of electron transport particles with unlabeled INH did not prevent the subsequent binding of [14C]NAD+, and unlabeled NAD+ did not block the binding of [3H]INH. [14C]NAD+ binding to electron transport particles was specific and reversible. Unlabeled NAD+ could both displace and prevent the binding of labeled nucleotide. Binding of [14C]NAD+ to electron transport particles was proportional to the incubation concentration of label, and NAD+ stimulation of NADH oxidase activity was related to the amount of NAD+ bound to electron transport particles. [3H]INH was irreversibly bound to electron transport particles. INH and NAD+, although operating at the same level of the electron transport chain, did not appear to compete for the same regulatory site.
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PMID:Site of action of isoniazid on the electron transport chain and its relationship to nicotinamide adenine dinucleotide regulation in Mycobacterium phlei. 742 5


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