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)

The study of the participation of metals in evolution of oxidation-reduction processes is subdivided into two periods. During the first of them, from 1897 to 1937, the significance of manganese, iron, titanium, molybdenum, vanadium and copper in most important processes of metabolism was discovered. The second period, from 1937 to 1977, was devoted to the study of the role of metals in individual representatives of oxidoreductases and their evolution during transition of organisms from anaerobiosis to aerobiosis. In this evolution of special importance were bimetallic enzymes, such as nitrogenase, some nitrate reductases and hydrogenases, carbon dioxide reductase, xanthine oxidase, cytochrome oxidase. Owing to their ability to accomplish conjugated oxidation-reduction reactions, these oxidoreductases were transitional to still more complicated polymetallic systems with whose participation the electron transfer chains in subcellular structures were formed.
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PMID:[Participation of polyvalent metals in the evolution of oxidoreductases]. 91 1

Under anaerobic circumstances in the presence of nitrate Paracoccus denitrificans is able to denitrify. The properties of the reductases involved in nitrate reductase, nitrite reductase, nitric oxide reductase, and nitrous oxide reductase are described. For that purpose not only the properties of the enzymes of P. denitrificans are considered but also those from Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas stutzeri. Nitrate reductase consists of three subunits: the alpha subunit contains the molybdenum cofactor, the beta subunit contains the iron sulfur clusters, and the gamma subunit is a special cytochrome b. Nitrate is reduced at the cytoplasmic side of the membrane and evidence for the presence of a nitrate-nitrite antiporter is presented. Electron flow is from ubiquinol via the specific cytochrome b to the nitrate reductase. Nitrite reductase (which is identical to cytochrome cd1) and nitrous oxide reductase are periplasmic proteins. Nitric oxide reductase is a membrane-bound enzyme. The bc1 complex is involved in electron flow to these reductases and the whole reaction takes place at the periplasmic side of the membrane. It is now firmly established that NO is an obligatory intermediate between nitrite and nitrous oxide. Nitrous oxide reductase is a multi-copper protein. A large number of genes is involved in the acquisition of molybdenum and copper, the formation of the molybdenum cofactor, and the insertion of the metals. It is estimated that at least 40 genes are involved in the process of denitrification. The control of the expression of these genes in P. denitrificans is totally unknown. As an example of such complex regulatory systems the function of the fnr, narX, and narL gene products in the expression of nitrate reductase in E. coli is described. The control of the effects of oxygen on the reduction of nitrate, nitrite, and nitrous oxide are discussed. Oxygen inhibits reduction of nitrate by prevention of nitrate uptake in the cell. In the case of nitrite and nitrous oxide a competition between reductases and oxidases for a limited supply of electrons from primary dehydrogenases seems to play an important role. Under some circumstances NO formed from nitrite may inhibit oxidases, resulting in a redistribution of electron flow from oxygen to nitrite. P. denitrificans contains three main oxidases: cytochrome aa3, cytochrome o, and cytochrome co. Cytochrome o is proton translocating and receives its electrons from ubiquinol. Some properties of cytochrome co, which receives its electrons from cytochrome c, are reported.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Metabolic regulation including anaerobic metabolism in Paracoccus denitrificans. 205 Jun 53

Using cyano-complexes of iron, tungsten, and molybdenum and a platinum working electrode, we have been able to attain and hold voltages in the range of 400 to 900 mV (vs. standard hydrogen electrode) in an aqueous medium. With this system we have obtained additional information in support of an earlier conclusion that cytochrome a3 has a high Em transition (i.e. greater than 460 mV) in addition to its Em in the 180-200 mV range (Hendler, R. W., K. V. S. Reddy, R. I. Shrager, and W. S. Caughey. 1986. Biophys. J. 49:717-729; Reddy, K. V. S., and R. W. Hendler. 1986. Biophys. J. 49:693-703). The proposed new transition has an Em near 770 mV and an n value greater than 1. The reduced form of the high-potential species of cytochrome a3 does not bind CO, in contrast to the reduced form of the low-potential species which does. A possible reaction scheme for cytochrome aa3 which incorporates the new information is presented.
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PMID:A new high potential redox transition for cytochrome aa3. 284 43

Kale (Brassica oleracea) and ryegrass (Lolium perenne)-clover (Trifolium repens) pasture grown under similar soil conditions were grazed in the vegetative state by growing lambs of 23.6 kg initial live weight for 24 weeks. Forty-eight lambs grazed each forage. The kale and pasture contained respectively 4 and 14 mg copper/kg dry matter (DM), 7.2 and 3.1 g total sulphur/kg DM and 0.4 and 1.1 mg molybdenum/kg DM. Subcutaneous injections of Cu (12 mg) were given to half the animals grazing each forage during weeks 1, 6, 12 and 18. All ninety-six animals were slaughtered at the end of the experiment and an additional group of twelve animals was slaughtered when the experiment commenced. Liver Cu was determined on all slaughtered animals and heart muscle cytochrome oxidase (EC 1.9.3.1) activity on those slaughtered at week 24. Blood samples removed at 6-week intervals were assayed for activity of superoxide dismutase (EC 1.15.1.1; SOD) and serum Cu concentration determined. Wool growth, live-weight gain and cytochrome oxidase activity of biopsied hind-limb muscle were also measured at 6-week intervals. Control animals grazing pasture showed an accumulation of total liver Cu during the experiment. Animals grazing this diet and given Cu injections showed an additional accumulation of liver Cu equivalent to the supplementary Cu administered, but Cu supplementation did not affect the activity of any of the Cu-containing enzymes measured and did not affect live-weight gain or wool growth. Control animals grazing kale showed a depletion of total liver Cu and reductions in serum Cu concentrations during weeks 18 and 24.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Copper metabolism in growing sheep given kale (Brassica oleracea) and ryegrass (Lolium perenne)-clover (Trifolium repens) fresh forage diets. 631 Dec 44

We report three children, each of whom seemed to have a primary mitochondrial disorder at presentation but was eventually diagnosed with an extramitochondrial inherited metabolic disease. The first patient presented at 6 months with developmental delay. Magnetic resonance imaging showed an abnormal signal in the white matter, and magnetic resonance spectroscopy showed elevated lactate peaks. A muscle biopsy showed complex IV deficiency, but leukocyte measurement of galactosylceramide beta-galactosidase activity was markedly diminished, consistent with Krabbe's disease. The second patient presented at birth with seizures and later had developmental delays. There was brain atrophy on neuroimaging. Serum and cerebrospinal fluid lactate levels were elevated. She had persistently elevated urine thiosulfate, which was diagnostic for molybdenum cofactor deficiency. The third child presented at 2 months with seizures and hypotonia. Magnetic resonance imaging showed an abnormal signal in the basal ganglia and surrounding white matter, whereas magnetic resonance spectroscopy showed elevated lactate peaks. A brain biopsy was diagnostic for Alexander's disease. These cases and others in the literature suggest that lactic acid elevation in the central nervous system can be found in a number of extramitochondrial neurologic diseases. Such diseases would constitute a third category of lactic acidosis.
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PMID:Lactic acid elevation in extramitochondrial childhood neurodegenerative diseases. 1157 6

Thiobacillus ferrooxidans AP19-3 oxidized molybdenum blue (Mo) enzymatically. Molybdenum oxidase in the plasma membrane of this bacterium was purified ca. 77-fold compared with molybdenum oxidase in cell extract. A purified molybdenum oxidase showed characteristic absorption maxima due to reduced-type cytochrome oxidase at 438 and 595 nm but did not show absorption peaks specific for c-type cytochrome. The optimum pH of molybdenum oxidase was 5.5. The activity of molybdenum oxidase was completely inhibited by sodium cyanide (5 mM) or carbon monoxide, and an oxidized type of cytochrome oxidase in a purified molybdenum oxidase was reduced by molybdenum blue, indicating that cytochrome oxidase in the enzyme plays a crucial role in molybdenum blue oxidation.
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PMID:Molybdenum oxidation by Thiobacillus ferrooxidans. 1634 10

Periplasmic substrate binding proteins are known for iron, zinc, manganese, nickel, and molybdenum but not copper. Synechocystis PCC 6803 requires copper for thylakoid-localized plastocyanin and cytochrome oxidase. Here we show that mutants deficient in a periplasmic substrate binding protein FutA2 have low cytochrome oxidase activity and produce cytochrome c6 when grown under copper conditions (150 nm) in which wild-type cells use plastocyanin rather than cytochrome c6. Anaerobic separation of extracts by two-dimensional native liquid chromatography followed by metal analysis and peptide mass-fingerprinting establish that accumulation of copper-plastocyanin is impaired, but iron-ferredoxin is unaffected in DeltafutA2 grown in 150 nm copper. However, recombinant FutA2 binds iron in preference to copper in vitro with an apparent Fe(III) affinity similar to that of its paralog FutA1, the principal substrate binding protein for iron import. FutA2 is also associated with iron and not copper in periplasm extracts, and this Fe(III)-protein complex is absent in DeltafutA2. There are differences in the soluble protein and small-molecule complexes of copper and iron, and the total amount of both elements increases in periplasm extracts of DeltafutA2 relative to wild type. Changes in periplasm protein and small-molecule complexes for other metals are also observed in DeltafutA2. It is proposed that FutA2 contributes to metal partitioning in the periplasm by sequestering Fe(III), which limits aberrant Fe(III) associations with vital binding sites for other metals, including copper.
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PMID:A periplasmic iron-binding protein contributes toward inward copper supply. 1714 38

Patients affected by sulfite oxidase (SO) deficiency present severe seizures early in infancy and progressive neurological damage, as well as tissue accumulation of sulfite, thiosulfate and S-sulfocysteine. Since the pathomechanisms involved in the neuropathology of SO deficiency are still poorly established, we evaluated the effects of sulfite on redox homeostasis and bioenergetics in cerebral cortex, striatum, cerebellum and hippocampus of rats with chemically induced SO deficiency. The deficiency was induced in 21-day-old rats by adding 200ppm of tungsten, a molybdenum competitor, in their drinking water for 9weeks. Sulfite (70mg/kg/day) was also administered through the drinking water from the third week of tungsten supplementation until the end of the treatment. Sulfite decreased reduced glutathione concentrations and the activities of glutathione reductase and glutathione S-transferase (GST) in cerebral cortex and of GST in cerebellum of SO-deficient rats. Moreover, sulfite increased the activities of complexes II and II-III in striatum and of complex II in hippocampus, but reduced the activity of complex IV in striatum of SO-deficient rats. Sulfite also decreased the mitochondrial membrane potential in cerebral cortex and striatum, whereas it had no effect on mitochondrial mass in any encephalic tissue evaluated. Finally, sulfite inhibited the activities of malate and glutamate dehydrogenase in cerebral cortex of SO-deficient rats. Taken together, our findings indicate that cerebral cortex and striatum are more vulnerable to sulfite-induced toxicity than cerebellum and hippocampus. It is presumed that these pathomechanisms may contribute to the pathophysiology of neurological damage found in patients affected by SO deficiency.
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PMID:Higher susceptibility of cerebral cortex and striatum to sulfite neurotoxicity in sulfite oxidase-deficient rats. 2752 30

Copper deficiency is an important disease of cattle that produces several clinical signs and lesions, due to alterations in copper-dependent enzymes. One of the organs affected by this deficiency is the heart (falling disease), but nevertheless, these cardiac lesions have not been extensively studied in bovines. The aim of this work was to propose a possible pathogenic mechanism for cardiac lesions in cattle affected by copper deficiency. Because of the possible existence of oxidative distress caused by low levels of copper-zinc-superoxide dismutase and cytochrome oxidase, ultrastructural and histological lesions have been evaluated in the heart of bovines in which a Cu deficiency had been induced using high molybdenum and sulfur levels in the diet. Our results indicated that copper deficiency produces significant damage in myocardium with high levels of lipid oxidation and a significant reduction in copper-zinc-superoxide dismutase activity leading to an oxidative distress situation. However, cytochrome oxidase activity was not significantly reduced. Histological observation revealed a significant increase in the amount of connective tissue, enlarged basement membranes of myocytes, and numerous Anichkov cells, in the hearts of deficient animals. Ultrastructural observation showed a significant enhancement in the mitochondrial volume density, with presence of lesions such as swelling and cristae disruption. We conclude that copper deficiency in bovines causes morphological lesions in the heart due to an oxidative damage produced by copper-dependent enzyme alterations.
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PMID:Biochemical and Morphological Alterations in Hearts of Copper-Deficient Bovines. 3011 59