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)

1. Increased specific activities of cytochrome c oxidase, catalase, succinate dehydrogenase, succinate-cytochrome c oxidoreductase, NADH-cytochrome c oxidoreductase and malate dehydrogenase were observed during glucose de-repression of Schizosaccharomyces pombe. 2. The cell-cycle of this organism was analysed by three different methods: (a) harvesting of cells at intervals from a synchronous culture, (b) separation of cells by rate-zonal centrifugation into different size classes and (c) separation of cells by isopycnic-zonal centrifugation into different density classes. 3. Measurement of enzyme activities during the cell-cycle showed that all the enzymes assayed [cytochrome c oxidase, catalase, acid p-nitrophenylphosphatase, NADH-dehydrogenase, NADH-cytochrome c oxidoreductase, NADPH-cytochrome c oxidoreductase, succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase (NADP) and fumarate hydratase] show periodic expression as ;peaks'. 4. Cytochrome c oxidase shows a single maximum at 0.67 of a cycle, whereas succinate dehydrogenase exhibits two maxima separated by 0.5 of a cell-cycle. 5. All other enzymes assayed showed two distinct maxima per cell-cycle; for catalase, malate dehydrogenase and NADPH-cytochrome c oxidoreductase there is the possibility of multiple fluctuations. 6. The single maximum of cytochrome c oxidase appears at a similar time in the cycle to one maximum of each of the other enzymes studied, except for NADH dehydrogenase. 7. These results are discussed with reference to previous observations on the expression of enzyme activities during the cell-cycle of yeasts.
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PMID:Oscillations of enzyme activities during the cell-cycle of a glucose-repressed fission-yeast Schizosaccharomyces pombe 972h-. 414 72

There exists considerable controversy regarding membrane topography in vesicles derived by osmotic lysis of spheroplasts of Gram-negative bacteria. It has been reported by others that bee venom can be used to quantitate the portion of a heterogeneous vesicle population with an inside-out orientation by determining the degree of loss of crypticity of NADH dehydrogenase activity. We have demonstrated that a major component of bee venom, melittin, causes an increase in the activity of several different respiratory enzymes in isolated membrane vesicles of Paracoccus denitrificans. The degree of stimulation produced by melittin is dependent upon (i) the nature of the respiratory substrates, (ii) the pH, (iii) the presence of Mg2+, (iv) the melittin: membrane protein ratio, and (v) the growth history of the cells from which the membrane vesicles were derived. Melittin-induced enhancement of TMPD:ascorbate and cytochrome c oxidase activities cannot be accounted for by increased accessibility of nonpermeant substrate to the interior of the vesicle. The stimulatory effect of melittin may rely in part on its ability to alter the proton permeability of the membrane thereby abolishing respiratory control. Collectively these observations call into question the usefulness of bee venom melittin in quantitative analyses of membrane topography. These results are consistent with the postulated existence of a homogeneous vesicle population in which the topography of the NADH dehydrogenase is different from that of the intact cell.
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PMID:The use of bee venom melittin to assess the topography of membrane vesicles derived from Paracoccus denitrificans. 625 50

Local anesthetics and alcohols were found to inhibit mitochondrial electron transport at several points along the chain. THe anesthetics employed were the tertiary amines procaine, tetracaine, dibucaine, and chlorpromazine, and the alcohols were n-butamol, n-pentanol, n-hexanol, and benzyl alcohol. Uncoupled sonic submitochondrial particles from beef heart and rat liver were studied. We report the following: (1) All of the anesthetics were found to inhibit each of the segments of the electron transport chain assayed; these included cytochrome c oxidase, durohydroquinone oxidase, succinate oxidase, NADH oxidase, succinate dehydrogenase, succinate-cytochrome c oxidoreductase, and NADH-cytochrome c oxidoreductase. (2) NADH oxidase and NADH-cytochrome c oxidoreductase required the lowest concentration of anesthetic for inhibition, and cytochrome c oxidase required the highest concentrations. (3) We conclude that there are several points along the chain at which inhibition occurs, the most sensitive being in the region of Complex I (NADH dehydrogenase). (4) Beef heart submitochondrial particles are less sensitive to inhibition than are rat liver particles. (5) Low concentrations of several of the anesthetics gave enhancement of electron transport activity, whereas higher concentrations of the same agents caused inhibition. (6) The concentrations of anesthetics (alcohol and tertiary amine) which gave 50% inhibition of NADH oxidase were lower than the reported concentrations required for blockage of frog sciatic nerve.
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PMID:Multiple sites of inhibition of mitochondrial electron transport by local anesthetics. 626 99

A yeast strain (SP1) resistant to glucose repression modified simultaneously in the fermentative and in the oxidative pathways (loss of alcohol dehydrogenase I and over production of cytochrome a + a3, being insensitive to the glucose effect) developed a secondary mitochondrial hydrogen pathway. Oxidative phosphorylation was measured with exogenous NADH as substrate on mitochondria derived from repressed or derepressed cells. In this strain, antimycin A promotes a partial inhibition of NADH oxidation but a complete inhibition of phosphorylation. Amytal partially inhibits oxidation of NADH but not phosphorylation. KCN inhibits NADH oxidation in a biphasic way (first level 0.1 mM, second level 5 mM) but phosphorylation was fully inhibited by 0.1 mM KCN. This alternative but non-phosphorylating pathway is insensitive to salicyl hydroxamate. The external NADH dehydrogenase, like cytochrome c oxidase is partially insensitive to catabolite repression. These results provide evidence for the presence in strain SP1 of an alternative mitochondrial pathway, going from the external NADH dehydrogenase to an oxidase, different from the normal NADH dehydrogenase ubiquinone pathway.
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PMID:Evidence for an alternative and non-phosphorylating pathway for NADH reoxidation in a yeast strain resistant to glucose repression. 630 24

Spontaneous mutants resistant to vanadate, arsenate or thiophosphate were isolated from a haploid strain of Saccharomyces cerevisiae. These three anions have an inhibitory effect on some mitochondrial functions and at the level of glyceraldehyde 3-phosphate dehydrogenase, a glycolysis enzyme. All the selected mutants had the same phenotype: they were deficient in alcohol dehydrogenase I, the terminal enzyme of the glycolysis, and possessed a high content of cytochrome c oxidase, the terminal enzyme of the respiratory chain. Moreover, cytochrome c oxidase biosynthesis had become insensitive to the catabolite repression, while the biosynthesis of the other enzymes sensitive to this phenomenon were always inhibited by glucose. Metabolic effects of this pleiotropic mutation manifested themselves in the following ways. 1. Growth rate and final cell mass were enhanced, compared to the wild type, when cells were grown on glucose or on glycerol, but not on lactate or ethanol. 2. Growth under anaerobiosis was nil and mutants did not ferment. 3. Mitochondrial respiration of the mutant strains was identical to the wild type with succinate or 2-oxo-glutarate as substrate, and weak with ethanol. But with added NADH, respiration rate of the mutants was higher than that of the wild type and partially insensitive to antimycin, even when cells were grown in repression conditions. It is postulated that in mutants strains, NADH produced at the level of glyceraldehyde 3-phosphate dehydrogenase, failing to be reoxidized via alcohol dehydrogenase, could be reoxidized with a high turnover owing to the enhancement of the amount of cytochrome c oxidase. Since NADH reoxidation is partially insensitive to antimycin, a secondary pathway going from external NADH dehydrogenase to cytochrome c oxidase is suggested.
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PMID:New mutants resistant to glucose repression affected in the regulation of the NADH reoxidation. 704 95

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

The interaction of xanthomegnin, a quinone pigment, with the mitochondrial respiratory chain was demonstrated. Xanthomegnin was reduced by succinate, in the presence of submitochondrial particles or mitochondria, only after all oxygen had been consumed in the system, and the reduction was inhibited by antimycin A or KCN. Xanthomegnin was immediately reduced by NADH in a similar system, the reduced xanthomegnin was reoxidized by oxygen but the reduction by NADH was not inhibited by antimycin A or KCN. Xanthomegnin was also immediately reduced by NADH catalyzed by a purified particulate NADH dehydrogenase complex showing a molar ratio of 2 moles NADH for one mole of xanthomegnin. Reoxidation of the reduced pigment by oxygen occurred in this system. Oxygen consumption was accelerated when xanthomegnin was added to a reaction medium containing NADH, NADH segment and cytochrome c oxidase. Subsequent addition of cytochrome c resulted in a further marked acceleration of oxygen consumption. These results suggest that xanthomegnin interacts with the NAD-linked respiratory chain to produce a xanthomegnin shunt, but this does not occur with the succinate-linked chain.
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PMID:The interaction of a quinone pigment, xanthomegnin, with the mitochondrial respiratory chain. 726 94

The relationships between bilayer lipid, diffusional and conformational activities of oxidoreduction components, and electron transfer activity in the mitochondrial inner membrane are considered. Using a new, low pH method to fuse liposome phospholipid (asolectin) with the isolated mitochondrial inner membrane, the membrane bilayer is enriched up to 700% with exogenous phospholipid. During such enrichment, ultrastructural analysis reveals that integral proteins diffuse freely and randomly into the expanding bilayer. Kinetic analysis reveals that a diffusion limited step occurs between succinate- and NADH dehydrogenase and cytochromes bc1, and that the dehydrogenases, ubiquinone, and cytochromes bc1 are free to diffuse independently of one another in the membrane plane. Whether cytochromes bc1 and cytochrome c oxidase codiffuse in the membrane plane, or diffuse independently of one another remains unclear. The specific activities of succinate- and NADH-dehydrogenase as well as cytochrome c oxidase are affected by bilayer enrichment. This most likely occurs through the direct modulation by the newly incorporated phospholipid on conformational activity required in the oxidoreductases for electron transfer.
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PMID:Relationships between bilayer lipid, motional freedom of oxidoreductase components, and electron transfer in the mitochondrial inner membrane. 742 10

Treatment of rats with hydroxycobalamin[c-lactam] (HCCL), a cobalamin antagonist, results in both increased hepatic mitochondrial content and the development of defects in mitochondrial ubiquinol:cytochrome c oxidoreductase and cytochrome c oxidase. The present study was designed to evaluate changes in hepatic mitochondrial RNA contents in response to HCCL treatment in rats. After 2 weeks of HCCL treatment, hepatic contents of the mature mitochondrial mRNAs (expressed normalized to 28 S rRNA) encoding subunit II of cytochrome c oxidase (CO II), subunit 1 of NADH dehydrogenase (ND1), and cytochrome b were reduced to values 40-60% of those observed in RNA from control liver tissue. In addition, HCCL induced a pronounced accumulation of high molecular weight RNA species which hybridized to mitochondrial probes and represented polycistronic RNA sequences. The polycistronic RNAs were products of the heavy strand of the mitochondrial genome, and major species demonstrated hybridization patterns consistent with identifications corresponding to the 12-16 S rRNA, 12-16 S-ND1, 16 S-ND1, and CO II-ATP synthase subunit 6 regions of the mitochondrial genome. Maximal expression of the polycistronic mitochondrial RNA was observed after 2 weeks of HCCL treatment. Thus, HCCL treatment interferes with mitochondrial RNA processing and decreases the content of mature mitochondrial mRNAs. Altered expression of the mitochondrial genome may be responsible for the decreased electron transport chain activity known to result from HCCL administration.
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PMID:Hepatic cobalamin deficiency induced by hydroxycobalamin[c-lactam] treatment in rats is associated with decreased mitochondrial mRNA contents and accumulation of polycistronic mitochondrial RNAs. 750 36

A lambda cDNA library prepared from polyadenylated RNA isolated from Daudi cells was differentially screened to isolate cDNAs that recognize mRNA whose levels are reduced following interferon (IFN) treatment. Southern blot and DNA sequence analysis of 20 cDNA clones that were isolated revealed that they represented mitochondrially encoded mRNAs for the following proteins: cytochrome c oxidase subunits II and III, ATPase 6, cytochrome b, and subunit 1 of the NADH dehydrogenase. Northern blot analysis employing these cDNAs and oligonucleotides generated to the remaining mitochondrially encoded mRNAs demonstrated that IFN-alpha treatment of Daudi cells mediates a time-dependent suppression of the level of all of the mitochondrially encoded mRNAs. Study of this IFN-mediated effect reveals that: (i) the suppression of the level of these mRNAs is dependent on protein synthesis, (ii) it can be observed to occur prior to any detectable effect on thymidine incorporation, (iii) the degree of suppression correlates with the sensitivity of the cells to the anticellular action of IFN, and (iv) the suppression of the level of these RNAs appears to result from an effect on the level of transcription rather than on the stability of these mRNAs. A study of the level of cellular respiration in IFN-treated Daudi cells reveals a clear suppression 3 h following IFN treatment.
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PMID:Suppression of mitochondrial mRNA levels and mitochondrial function in cells responding to the anticellular action of interferon. 751 85


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