Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.7.1.2 (nitrate reductase)
 3,861 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Membrane fractions with L-lactate dehydrogenase, sn-glycerol-3-phosphate (G3P) dehydrogenase, and nitrate reductase activities were prepared from Staphylococcus aureus wild-type and hem mutant strains. These preparations reduced ferric to ferrous iron with L-lactate or G3P as the source of reductant, using ferrozine to trap the ferrous iron. Reduction of ferric iron was insensitive to 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO) with either L-lactate or G3P as reductant, but oxalate and dicumarol inhibited reduction with L-lactate as substrate. The membranes had L-lactate- and G3P-nitrate reductase activities, which were inhibited by azide and by HQNO. Reduction of ferric iron under anaerobic conditions was inhibited by nitrate with preparations from the wild-type strain. This effect of nitrate was abolished by blocking electron transport to the nitrate reductase system with azide or HQNO. Nitrate did not inhibit reduction of ferric iron in heme-depleted membranes from the hem mutant unless hemin was added to restore L-lactate- and G3P-nitrate reductase activity. We conclude that reduced components of the electron transport chain that precede cytochrome b serve as the source of reductant for ferric iron and that these components are oxidized preferentially by a functional nitrate reductase system.
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PMID:Reduction of ferric iron by L-lactate and DL-glycerol-3-phosphate in membrane preparations from Staphylococcus aureus and interactions with the nitrate reductase system. 20 71

Squash cotyledon NADH:nitrate reductase catalyzes the reduction of the siderophore ferrioxamine B. The enzyme also reduced ferric ion in a buffer system containing the chelators oxalate and maleate. Ferrioxamine B reduction was maximal at pH 4; ferric ion reduction was maximal at pH 8. The present study indicates that iron assimilation by higher plants may occur with microbial siderophores serving as ferric ion sources and nitrate reductase functioning as the siderophore reductase.
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PMID:Siderophore reduction catalyzed by higher plant NADH:nitrate reductase. 623 24