Characterization of the Reduced Nicotinamide Adenine Dinucleotide Phosphate-Nitrate Reductase of Aspergillus nidulans

摘要: The reduced nicotinamide adenine dinucleotide phosphate (NADPH)-nitrate oxidoreductase (EC 1.6.6.2) from Aspergillus nidulans was purified over 200-fold by use of salt fractionation, gel filtration, and ion-exchange chromatography. enzyme specific for NADPH catalyzed reduction nitrate, cytochrome c isolated mitochondria Aspergillus, mammalian c. An S(0.725) (20, w) 7.8 derived with sucrose density gradient centrifugation, a Stokes radius 6.4 nm filtration on Sephadex G-200. From these values, molecular weight 197,000 computed, assuming v = 0.725 cm(3)/g. spectral properties the suggested flavine component present but revealed no pattern indicative hemoprotein. A c, similar to mitochondria, found unassociated nitrate reductase after No NADPH-nitrate activity detected in mitochondria. Spectrally discernable at 450 noted reaction NADPH. This inhibited p-chloromercuribenzoate not KCN. addition caused reoxidation via which KCN p-chloromercuribenzoate. half-life 37 C 20 min 35 NADPH-cytochrome reductase.