title: Denitration of peroxynitrite-treated proteins by 'protein nitratases' from rat brain and heart.
abstract: Putative 'protein nitratases,' which catalyze denitration of peroxynitrite (PN)-treated proteins, were detected in the homogenate/crude extract of rat brains and hearts. Nitratase activity was monitored by the decreased intensity of nitrotyrosine immunoreactive-bands in Western blot and increased nitrate level in dialysate of incubation mixture, which contained homogenate/crude extract, protease inhibitors and a PN-treated substrate, such as treated histone (III-S), BSA or invertase. Enhanced activity of nitratases was noted by preincubating crude extract with Ca2+. In addition, at least two types of nitratases may occur: type I, reductant-dependent, and type II, reductant- independent. Furthermore, upon denitration, the activity of PN-treated invertase increased to the same activity level of the untreated invertase. The overall reaction catalyzed by nitratases for denitration of nitrotyrosine residues in protein could be as follows: Protein-Tyr-NO2 + H2O --> Protein-Tyr-H + H+ + NO3-. The nitration/denitration of protein-tyrosine may be crucial in regulating signal transduction.
authors.affiliation: Division of Science and Mathematics, Bethune-Cookman College, Daytona Beach, Florida 32114, USA.
authors.forename: W N
authors.initials: WN
authors.lastname: Kuo
authors.forename: R N
authors.initials: RN
authors.lastname: Kanadia
authors.forename: V P
authors.initials: VP
authors.lastname: Shanbhag
authors.forename: R
authors.initials: R
authors.lastname: Toro
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D003956:Dialysis; D004798:Enzymes / Q000737:chemistry / Q000378:metabolism*; D005182:Flavin-Adenine Dinucleotide / Q000031:analogs & derivatives / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D009566:Nitrates / Q000032:analysis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D011506:Proteins / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D014020:Tissue Extracts / Q000737:chemistry / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism; D043324:beta-Fructofuranosidase
chemical_list: D004798:Enzymes; D009566:Nitrates; D011506:Proteins; D014020:Tissue Extracts; D009243:NAD; D005182:Flavin-Adenine Dinucleotide; C058805:1,5-dihydro-FAD; C039642:peroxynitric acid; D012710:Serum Albumin, Bovine; C002744:3-nitrotyrosine; D014443:Tyrosine; D009249:NADP; D005982:Glutathione Transferase; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase; D005978:Glutathione; D002118:Calcium