title: Invitro formation of assimilatory reduced nicotinamide adenine dinucleotide phosphate: nitrate reductase from a Neurospora mutant and a component of molybdenum-enzymes.
abstract: An active Neurospora-like assimilatory NADPH-nitrate reductase (EC 1.6.6.2), which can be formed in vitro by incubation of extracts of nitrate-induced Neurospora crassa mutant nit-1 with extracts of (a) certain other nonallelic nitrate reductase mutants, (b) uninduced wild type, or (c) xanthine oxidizing and liver aldehyde-oxidase systems was also formed by combination of the nit-1 extract with other acid-treated enzymes known to contain molybdenum. These molybdenum enzymes included (a) nitrogenase, or its molybdenum-iron protein, from Clostridium, Azotobacter, and soybeannodule bacteroids, (b) bovine liver sulfite oxidase, (c) respiratory formate-nitrate reductase from Escherichia coli, (d) NADH-nitrate reductase from foxtail grass (Setaria faberii), and (e) FADH(2)- and reduced methyl viologennitrate reductase preparations from certain Neurospora mutants. Several molybdenum-amino-acid complexes, as possible catalytic models of nitrogenase, were inactive (as were some previously tested 20 nonmolybdenum enzymes) in place of the acid-treated molybdenum-containing enzymes. The results imply the existence of a molybdenum-containing component shared by the known molybdenum-enzymes.
mesh_terms: D000818:Animals; D001395:Azotobacter / Q000201:enzymology; D002417:Cattle; D003013:Clostridium / Q000201:enzymology; D004926:Escherichia coli / Q000201:enzymology; D005182:Flavin-Adenine Dinucleotide; D066298:In Vitro Techniques; D007501:Iron; D008099:Liver / Q000201:enzymology; D008982:Molybdenum; D009154:Mutation; D009249:NADP; D009491:Neurospora / Q000201:enzymology*; D009492:Neurospora crassa / Q000201:enzymology; D010088:Oxidoreductases; D006109:Poaceae / Q000201:enzymology; D013025:Glycine max / Q000201:enzymology; D013447:Sulfites; D014970:Xanthines
chemical_list: D013447:Sulfites; D014970:Xanthines; D005182:Flavin-Adenine Dinucleotide; D009249:NADP; D008982:Molybdenum; D007501:Iron; D010088:Oxidoreductases