Nitrite dehydrogenase

Oxygen atom transfer fnechanism of nitrite dehydrogenase from Nitrobacter agilis. The filled-in oxygen atom tepresents O. The lower pathway provides for O exchange with water, a process that competes with O atom transfer from nitrate to nitrite. M represents a molybdenum atom. From Friedman et... 

Friedman, S. H., Massefski, W., and Hollocher, T. C. (1986). Catalysis of intermolecular oxygen atom transfer by nitrite dehydrogenase of Nitrobacter agilis. J. Biol. Chem. 261, 10538-10543. 

The final step in the nitrification process is the oxidation of nitrite to nitrate by the enzyme nitrite oxidase (NoX) or, more properly nitrite dehydrogenase, via the reaction ... 

Others oxotransferases) (2 pyranopterins bonded to Mo) (8-10 members) Nitrate reduction dissimilatory terminal respiratory oxidase Pyridoxal oxidase Xanthine dehydrogenases Pyrogallol transhydrolase Nitrate to nitrite... 

NITRATE REDUCTASE NITRITE REDUCTASE PHENOL HYDROXYLASE PROLINE DEHYDROGENASE PUTRESCINE OXIDASE PYRUVATE OXIDASE SALICYLATE 1-MONOOXYGENASE SUCCINATE DEHYDROGENASE SULFITE REDUCTASE XANTHINE OXIDASE Falling ball viscometry,... 

R)-2-METHYLMALATE DEHYDRATASE NICOTINATE DEHYDROGENASE NITRATE REDUCTASE NITRITE REDUCTASE PHENYLALANINE MONOOXYGENASE PROLYL 3-HYDROXYLASE PROLYL 4-HYDROXYLASE PROTOCATECHUATE 3,4-DIOXYGENASE PROTOCATECHUATE 4,5-DIOXYGENASE RIESKE IRON-SULFUR PROTEIN RUBREDOXIN... 

After 2- days of repeated NG exposure, tolerance to the vasodilatory activity occurs, probably as a result of compensatory vasoconstriction. Tolerance may be lost during periods without NG exposure, such as weekends and holidays. Recent smdies have suggested that tolerance may be mediated by a mitochondrial aldehyde dehydrogenase that catalyzes the formation of 1,2-glyceryl dinitrate and nitrite from NG, leading to production of cGMP and relaxation of vascular smooth muscle. ... 

The blue protein from A. faecalis strain S-6, which was isolated as a requirement for transferring electrons to a copper-containing nitrite reductase, has since been shown to have sequence homology with proteins arbitrarily designated pseudoazurin by Ambler and Tobari (1985), from Achromobacter cycloclastes and from Pseudomonas AMI. [Pseudomonas AMI also produces amicyanin, which is the recipient of electrons from methylamine dehydrogenase, (see below)]. In A. cycloclastes reduced pseudoazurin donates electrons to a copper nitrite reductase (Liu et ai, 1986), as it does in A. faecalis. Ambler and Tobari (1985)... 

As noted earlier, peroxynitrite is formed with a diffusion-controlled rate from superoxide and nitric oxide (Reaction 10). As both these radicals are ubiquitous species, which present practically in all cells and tissues, peroxynitrite can be the most important species responsible for free radical-mediated damage in biological systems. Moreover, it is now known that NO synthases are capable of producing superoxide and nitric oxide simultaneously (see Chapter 22), greatly increasing the possible rate of peroxynitrite production. In addition, another enzyme xanthine dehydrogenase is also able to produce peroxynitrite in the presence of nitrite... 

Acetaldehyde is oxidized to acetic acid by NAD+-dependent aldehyde dehydrogenases (ALDH) in liver and nasal mucosal preparations. Its administration to rats causes an increase in urinary excretion of sulfur metabolites and it is known to react with cysteine to produce a thiazolidine 4-carboxylic acid derivative that can be A -nitro-sated in vivo upon co-administration of nitrite (lARC, 1985). Many studies have been published subsequently, but these have been mainly in the context of ethanol metabolism. 

Iron-sulfur clusters are found in flavoproteins such as NADH dehydrogenase (Chapter 18) and trimethylamine dehydrogenase (Fig. 15-9) and in the siroheme-containing sulfite reductases and nitrite reductases.312 These two reductases are found both in bacteria and in green plants. 

Membranes from nitrate-grown cells contain many cytochromes and dehydrogenases, including cytochromes b, d and a,. One of the b-type cytochromes is specifically associated with the nitrite reductase, and another with formate dehydrogenase whose synthesis is also induced by the presence of nitrate. These components have been reviewed.1436... 

Achromobacter fischeri, nitrite reductase, physical properties, 277-279 Active site, lipoamide dehydrogenase, 105 Acyl hydrazides, catalase and, 379 Acyltransferase activity, glyceraldehyde-... 

Azotobacter agile, transhydrogenase of, 54 Azotobacter chroococcum nitrite reductase of, 275, 276-277 transhydrogenase of, 54 Azotobacter vinelandii NADH dehydrogenase of, 221... 

---