Nitrite reductase (cytochrome c,d1) was purified from Pseudomonas aeruginosa. In the presence of the reducing system, ascorbate-N,N,N',N'-tetramethylphenyl-enediamine, which alone had no ability to reduce nitrite or NO at pH 7.5, the enzyme catalyzed the reduction of nitrite to NO and N2O as major and minor products, respectively, as determined by gas chromatography-mass spectrometry. The rate ...

A series of copper complexes have been synthesised as potential agents for the catalytic reduction of nitrite anions. The ligands and corresponding copper complexes have been characterised by using a range of techniques including X-ray crystallography, NMR, microanalysis, mass spectrometry, infra-red spectroscopy, electrochemical studies and density functional theory calculations. For complexes...

Nitrite reductases (NiRs) are enzymes found in prokaryotic organisms which catalyze the one-electron (e ) reduction of nitrite to nitric oxide (NO). Copper nitrite reductases (CuNiRs) are homotrimeric enzymes with each monomer containing two copper centers: a T1 site for electron transfer, and a catalyticallyactive T2 site. Although X-ray crystallographic studies have provided structural snapsh...

Various enzymic systems, such as nitrite reductase, sulfite reductase and glutathione reductase, have been proposed for, or suspected to be involved in, the reduction of selenite in bacteria. As alphaproteobacteria have been shown to be highly tolerant to transition metal oxyanions, it seemed interesting to investigate the hypothetical involvement of these different enzymes in the reduction of ...

AIMS Nitrite (NO₂⁻), now regarded as an endocrine reserve of nitric oxide (NO), is bioactivated by nitrite reductase enzymes to mediate physiological responses. In blood, haemoglobin (Hb) catalyses nitrite reduction through a reaction modulated by haem redox potential and oxygen saturation, resulting in maximal NO production around the Hb P₅₀. Although physiological studies demonstrate that Hb-...

Abstract: In this study, we were investigated behavior the electrochemical reductionof nitrite at a hemoglobin (Hb) immobilized on glass carbon electrode (GCE) containingpolypyrol nanofiber (ppy) films. Polypyrrole (PPy) nanofibers have been constructed onGCE applying electrochemical technique, and can to deposit diverse polymers onminiaturized electrodes with this commo...

The biological nitrogen cycle involves step-wise reduction of nitrogen oxides to ammonium salts and oxidation of ammonia back to nitrites and nitrates by plants and bacteria. Neither process has been thought to have relevance to mammalian physiology; however in recent years the salivary bacterial reduction of nitrate to nitrite has been recognized as an important metabolic conversion in humans....

A synthetic growth medium was purified with the chelator 1,5-diphenylthiocarbazone to study the effects of copper on partial reactions and product formation of nitrite respiration in Pseudomonas perfectomarinus. This organism grew anaerobically in a copper-deficient medium with nitrate or nitrite as the terminal electron acceptor. Copper-deficient cells had high activity for reduction of nitrat...