This work reports the development of a bienzyme system consisting of salicylate hydroxylase (SHL) and nitrate reductase (NaR) for the electrochemical determination of nitrate. This method measures the concentration of nitrate directly under ambient air without suffering from oxygen interferences. The determination is based on the detection of NADH consumption, and the principle is as follows: N...

Differences in the amino acid sequence between the bispecific NAD(P)H-nitrate reductase of birch (Befula pendula Roth) and the monospecific NADH-nitrate reductases of a variety of other higher plants have been found at the dinucleotide-binding site in the FAD domain. To pinpoint amino acid residues that determine the choice of reducing substrate, we introduced mutations into the cDNA coding for...

The 4S cytochrome c (Cyt c) reductase activity of several plant species was markedly stimulated by cyanide and ferrocyanide but those of the 8S nitrate reductase component and other particulate components of the maize (Zea mays L.) scutellum by comparison, were increased only slightly. The effect of cyanide and ferrocyanide was not due to elimination of cytochrome oxidase interference but resul...

The assimilatory nitrate reductase from Chlorella contains flavin, heme, and molybdenum as prosthetic groups. The molybdenum in assimilatory nitrate reductase is associated with a pterin moiety (molybdopterin) as evidenced by the ability of the enzyme to donate active molybdenum cofactor to the Neurospora nitrate reductase mutant nit-1 and by the oxidative conversion of the pterin to two well c...

The assimilatory nitrate reductase from Chlorella contains flavin, heme, and molybdenum as prosthetic groups. The molybdenum in assimilatory nitrate reductase is associated with a pterin moiety (molybdopterin) as evidenced by the ability of the enzyme to donate active molybdenum cofactor to the Neurospora nitrate reductase mutant nit-1 and by the oxidative conversion of the pterin to two well c...

Nitrate reductase induction by nitrate and repression by NH,+ has been studied extensively in the simple eukaryote Aspergillus nidulans (Pateman & Cove, 1967; Cove & Pateman, 1968). Wild-type cells grown on minimal medium, with 20m~-NaNO~ as the nitrogen source, rapidly lose nitrate reductase activity when transferred either to minimal medium without N (-N medium) or to minimal medium without C...

Seven known genes control Pseudomonas aeruginosa nitrate assimilation. Three of the genes, designated nas, are required for the synthesis of assimilatory nitrate reductase: nasC encodes a structural component of the enzyme; nasA and nasB encode products that participate in the biosynthesis of the molybdenum cofactor of the enzyme. A fourth gene (nis) is required for the synthesis of assimilator...

The nitrite-reducing activity of the normal susceptible biotype of lambsquarters (Chenopodium album L.) was strongly inhibited by atrazine in the assay medium, both in the case of the in vivo assays of leaf discs in light, and in vitro photoreduction assays of crude extracts. In vitro assays of crude extracts with methylviologen or ferredoxin supplying the reducing potential were not inhibited ...