title: Inactivation of the NADH-dependent activities of nitrate reductase by ferrate.
abstract: Nitrate reductase (EC 1.6.6.1) from Chlorella vulgaris, a flavin-cytochrome-molybdenum enzyme, catalyses two types of partial reactions: reduction of exogenous cytochrome c by NADH and reduction of nitrate to nitrite by reduced methyl viologen (reduced 1,1'-dimethyl-4,4'-dipyridine dichloride). Ferrate, an analogue of orthophosphate acting on the phosphate-binding region of the enzymes, abolishes the NADH-nitrate reductase as well as the NADH-cytochrome c activities. In addition, the ability of NADH to reduce the endogenous cytochrome b component of the enzyme is also impaired. The reduction of nitrate by reduced methyl viologen is only partially affected. The results indicate that the ferrate primarily disrupts the NADH site.
mesh_terms: D001426:Bacterial Proteins; D002708:Chlorella / Q000201:enzymology; D003573:Cytochrome b Group / Q000378:metabolism; D005293:Ferritins; D006902:Hydroxymercuribenzoates / Q000494:pharmacology; D007501:Iron / Q000494:pharmacology*; D007700:Kinetics; D009243:NAD / Q000378:metabolism*; D009565:Nitrate Reductases / Q000037:antagonists & inhibitors*; D010710:Phosphates / Q000494:pharmacology; D013438:Sulfhydryl Compounds / Q000032:analysis
chemical_list: D001426:Bacterial Proteins; D003573:Cytochrome b Group; D006902:Hydroxymercuribenzoates; D010710:Phosphates; D013438:Sulfhydryl Compounds; D009243:NAD; C017311:ferrate ion; D005293:Ferritins; C018032:bacterioferritin; D007501:Iron; D009565:Nitrate Reductases