Reduced ferredoxin can serve as electron donor in the 6-electron reduction of nitrite to ammonia catalyzed by spinach nitrite reductase. We have examined interactions between nitrite reductase and its substrates, ferredoxin and nitrite, with emphasis upon protein-protein interactions between ferredoxin and nitrite reductase. Ferredoxin, of the proteins tested, is the most effective in retarding...

Steady state rates of NADP reduction decline upon commencement of nitrite reduction in reconstituted chloroplast preparations. Similarly, steady state rates of nitrite reduction are lower, but not zero, during concurrent NADP reduction. These results imply that competition for substrate occurs and suggest that nitrite reduction can successfully compete for reduced ferredoxin, even at high rates...

Klebsiella aerogenes W70 could grow aerobically with nitrate or nitrite as the sole nitrogen source. The assimilatory nitrate reductase and nitrite reductase responsible for this ability required the presence of either nitrate or nitrite as an inducer, and both enzymes were repressed by ammonia. The repression by ammonia, which required the NTR (nitrogen regulatory) system (A. Macaluso, E. A. B...

In vitro assembly or complementation of a hybrid assimilatory nitrate reductase was attained by mixing a preparation of nitrate-induced N. crassa mutant nit-1 specifically with acid-treated (pH 2.5) bovine milk or intestinal xanthine oxidase, rabbit liver aldehyde oxidase, or chicken liver xanthine dehydrogenase. The complementation reaction specifically required induced nit-1, the only nitrate...

The cytochrome c nitrite reductase (ccNiR) from Desulfovibrio desulfuricans ATCC 27774 is able to reduce nitrite to ammonia in a six-electron transfer reaction. Although extensively characterized from the spectroscopic and structural points-of-view, some of its kinetic aspects are still under explored. In this work the kinetic behaviour of ccNiR has been evaluated in a systematic manner using t...

Biological electron transfer is a fundamentally important reaction. Despite the apparent simplicity of these reactions (in that no bonds are made or broken), their experimental interrogation is often complicated because of adiabatic control exerted through associated chemical and conformational change. We have studied the nature of this control in several enzyme systems, cytochrome P450 reducta...

Three enzymes contribute to the total hydroxylamine reductase activity of corn (Zea mays L.) scutellum extracts. Two of these resemble enzymes previously prepared from leaves, while the third, which accounts for a major part of the activity, appears to have no counterpart in leaf tissue. One of the hydroxylamine reductases found only in small amounts is associated with nitrite reductase and is ...

background anaerobic-inducible promoters are alternatives of chemical-inducible promoters for expression of recombinant proteins especially in conditions where chemical induction is not possible or anaerobic conditions are preferable. the nirb promoter is the promoter of the first gene of nir operon in escherichia coli, which encodes nadh-dependent nitrite reductase. this promoter is naturally ...

Renal oxidative stress and nitric oxide (NO) deficiency are key events in hypertension. Stimulation of a nitrate-nitrite-NO pathway with dietary nitrate reduces blood pressure, but the mechanisms or target organ are not clear. We investigated the hypothesis that inorganic nitrate and nitrite attenuate reactivity of renal microcirculation and blood pressure responses to angiotensin II (ANG II) b...

During anaerobic nitrate respiration Bacillus subtilis reduces nitrate via nitrite to ammonia. No denitrification products were observed. B. subtilis wild-type cells and a nitrate reductase mutant grew anaerobically with nitrite as an electron acceptor. Oxygen-sensitive dissimilatory nitrite reductase activity was demonstrated in cell extracts prepared from both strains with benzyl viologen as ...