Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

VanDemark, P. J. (University of South Dakota, Vermillion), and P. F. Smith. Respiratory pathways in the Mycoplasma. II. Pathway of electron transport during oxidation of reduced nicotinamide adenine dinucleotide by Mycoplasma hominis. J. Bacteriol. 88:122-129. 1964.-Unlike the flavin-terminated respiratory pathway of the fermentative Mycoplasma, the respiratory chain of the nonfermentative M. hominis strain 07 appears to be more complex, involving quinones and cytochromes in addition to flavins. In addition to reduction by reduced nicotine adenine dinucleotide (NADH) and reduced nicotine adenine dinucleotide phosphate, nonpyridine nucleotide-linked reduction of the respiratory chain of this organism occurred with succinate, lactate, and short-chained acyl coenzyme A derivatives as electron donors. Enzymes catalyzing the oxidation of NADH included an NADH oxidase, a diaphorase, a quinone reductase, and a cytochrome c reductase. The oxidation of NADH was sensitive to a variety of inhibitors, including 10(-4)m Atabrine, 10(-3)m sodium amytal, 10(-5)mp-chloromercuribenzoate, 10(-4)m antimycin A, and 10(-4)m potassium cyanide. The oxidase was resolved by the addition of 5% trichloroacetic acid and reactivated by the addition of flavin adenine dinucleotide but not flavin mononucleotide. The M. hominis sonic extract contained an NADH-coenzyme Q reductase. The oxidation of NADH was stimulated by the addition of either menadione or vitamin K(2) (C(35)). The oxidase was inactivated by extraction with ether or irradiation at 360 mmu. The ether-inactivated enzyme was partially reactivated by the addition of "lipid" extract of the enzyme and coenzyme Q(6). Difference spectra of the cell extracts revealed the presence of "b" and "a" type cytochromes. These cell extracts were found to contain a cyanide-and azide-sensitive cytochrome oxidase and catalase.
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PMID:RESPIRATORY PATHWAYS IN THE MYCOPLASMA. II. PATHWAY OF ELECTRON TRANSPORT DURING OXIDATION OF REDUCED NICOTINAMIDE ADENINE DINUCLEOTIDE BY MYCOPLASMA HOMINIS. 1419 76

Niederpruem, Donald J. (Indiana University Medical Center, Indianapolis). Respiration of basidiospores of Schizophyllum commune. J. Bacteriol. 88:210-215. 1964.-The aerobic metabolism of basidiospores of the wood-rotting mushroom Schizophyllum commune was investigated by use of manometric techniques and specific respiratory poisons. Basal respiration was stimulated markedly by the uncoupling agent 2,4-dinitrophenol. This effect was pH-dependent and was sensitive to antimycin A. A positive periodic acid-Schiff reaction and a respiratory quotient (CO(2)/O(2)) of near unity pointed to carbohydrate as the endogenous substrate. Oxygen consumption was increased by sucrose, certain hexoses, d-xylose, acetate, and ethanol. Oxidative assimilation was evident with d-glucose and acetate. Glucose oxidation was inhibited by cyanide, azide, antimycin A, Atabrine, and phenylmercuric acetate. These data implicate cytochrome oxidase, b- and c-type cytochromes, flavoprotein, and essential sulfhydryl groups in basidiospore respiration.
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PMID:RESPIRATION OF BASIDIOSPORES OF SCHIZOPHYLLUM COMMUNE. 1419 90

Pepper, Rollin E. (Michigan State University, East Lansing), and Ralph N. Costilow. Electron transport in Bacillus popilliae. J. Bacteriol. 89:271-276. 1965.-Bacillus popilliae was found to be unique among aerobic microorganisms in that it was deficient in a hydrogen peroxide-scavenging system. Neither catalase nor peroxidase was found. At the same time, a system for producing hydrogen peroxide during oxidation of reduced nicotinamide adenine dinucleotide (NADH(2)) was consistently present in the soluble fraction of extracts of cells from older cultures. Cells harvested from 9-hr cultures did not produce a significant amount of peroxide. The soluble NADH(2) oxidase was apparently a flavoprotein, since it was stimulated by flavin nucleotides, insensitive to cyanide and azide, and inhibited by Atabrine. Also, difference spectra demonstrated the presence of a reducible flavin in the soluble fraction of cell extracts. The particulate fraction of cell extracts was shown by difference spectra to contain cytochrome b(1); the strong inhibition of NADH(2) oxidation by cyanide, azide, and carbon monoxide indicated that a terminal cytochrome oxidase was also present. This system was also flavin-dependent, since it was strongly inhibited by Atabrine. The specific activity of the NADH(2) oxidase in the particulate fraction was lower in extracts of cells from older cultures than in those from exponentially growing cultures. Cytochrome c was not found in extracts of these cells. It is believed that the increased participation of the hydrogen peroxide-generating NADH(2) oxidase in cells of older cultures may be responsible for the rapid loss in cell viability noted in stationary-phase cultures.
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PMID:ELECTRON TRANSPORT IN BACILLUS POPILLIAE. 1425 89

Oxidation of Fe2+, ascorbic acid, propyl gallate, tiron, L-cysteine, and glutathione by Acidithiobacillus ferrooxidans was studied with respect to the effect of electron transport inhibitors and uncouplers on the rate of oxidation. All the oxidations were sensitive to inhibitors of cytochrome c oxidase, KCN, and NaN3. They were also partially inhibited by inhibitors of complex I and complex III of the electron transport system. Uncouplers at low concentrations stimulated the oxidation and inhibited it at higher concentrations. The oxidation rates of Fe2+ and L-cysteine inhibited by complex I and complex III inhibitors (amytal, rotenone, antimycin A, myxothiazol, and HQNO) were stimulated more extensively by uncouplers than the control rates. Atabrine, a flavin antagonist, was an exception, and atabrine-inhibited oxidation activities of all these compounds were further inhibited by uncouplers. A model for the electron transport pathways of A. ferrooxidans is proposed to account for these results. In the model these organic substrates reduce ferric iron on the surface of cells to ferrous iron, which is oxidized back to ferric iron through the Fe2+ oxidation pathway, leading to cytochrome oxidase to O2. Some of electrons enter the uphill (energy-requiring) electron transport pathway to reduce NAD+. Uncouplers at low concentrations stimulate Fe2+ oxidation by stimulating cytochrome oxidase by uncoupling. Higher concentrations lower deltap to the level insufficient to overcome the potentially uphill reaction at rusticyanin-cytochrome c4. Inhibition of uphill reactions at complex I and complex III leads to deltap accumulation and inhibition of cytochrome oxidase. Uncouplers remove the inhibition of deltap and stimulate the oxidation. Atabrine inhibition is not released by uncouplers, which implies a possibility of atabrine inhibition at a site other than complex I, but a site somehow involved in the Fe2+ oxidation pathway.
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PMID:Effects of electron transport inhibitors and uncouplers on the oxidation of ferrous iron and compounds interacting with ferric iron in Acidithiobacillus ferrooxidans. 1623 67