title: Peroxynitrite treatment in vitro disables catalytic activity of recombinant p38 MAPK.
abstract: Protein tyrosine nitration is a post-translational modification occurring under conditions of oxidative stress in a number of diseases. The causative agent of tyrosine nitration is the potent prooxidant peroxynitrite that results from the interaction of nitric oxide and superoxide. We have previously demonstrated existence of nitrotyrosine in placenta from pregnancies complicated by preeclampsia, which suggested the possibility of the existence of nitrated proteins. Nitration of various proteins has been demonstrated to more commonly result in loss of protein function. Potential nitration of p38 MAPK, a critical signaling molecule has been suggested and also tentatively identified in certain in vivo systems. In this study we demonstrate for the first time nitration of recombinant p38 MAPK in vitro and an associated loss of its catalytic activity. LC-MS data identified tyrosine residues Y132, Y245 and Y258 to be nitrated. Nitration of these specific residues was deduced from the 45.0-Da change in mass that these residues exhibited that was consistent with the loss of a proton and addition of the nitro group.
authors.affiliation: Department of Obstetrics and Gynecology, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0526, USA. rose.webster@uc.edu
authors.forename: Rose P
authors.initials: RP
authors.lastname: Webster
authors.forename: Stephen
authors.initials: S
authors.lastname: Macha
authors.forename: Diane
authors.initials: D
authors.lastname: Brockman
authors.forename: Leslie
authors.initials: L
authors.lastname: Myatt
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis / Q000187:drug effects; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009566:Nitrates / Q000737:chemistry / Q000378:metabolism; D030421:Peroxynitrous Acid / Q000494:pharmacology*; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D009566:Nitrates; D020033:Protein Isoforms; D011994:Recombinant Proteins; D030421:Peroxynitrous Acid; D014443:Tyrosine; D048051:p38 Mitogen-Activated Protein Kinases