title: Peroxynitrite, a stealthy biological oxidant.
abstract: Peroxynitrite is the product of the diffusion-controlled reaction of nitric oxide and superoxide radicals. Peroxynitrite, a reactive short-lived peroxide with a pKa of 6.8, is a good oxidant and nucleophile. It also yields secondary free radical intermediates such as nitrogen dioxide and carbonate radicals. Much of nitric oxide- and superoxide-dependent cytotoxicity resides on peroxynitrite, which affects mitochondrial function and triggers cell death via oxidation and nitration reactions. Peroxynitrite is an endogenous toxicant but is also a cytotoxic effector against invading pathogens. The biological chemistry of peroxynitrite is modulated by endogenous antioxidant mechanisms and neutralized by synthetic compounds with peroxynitrite-scavenging capacity.
authors.affiliation: From the Departamento de Bioquímica and Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, 11800 Montevideo, Uruguay.
authors.forename: Rafael
authors.initials: R
authors.lastname: Radi
mesh_terms: D000818:Animals; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008928:Mitochondria / Q000378:metabolism; D009569:Nitric Oxide / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry*; D010084:Oxidation-Reduction; D030421:Peroxynitrous Acid / Q000737:chemistry*; D013482:Superoxide Dismutase / Q000737:chemistry; D013481:Superoxides / Q000737:chemistry; D014443:Tyrosine / Q000737:chemistry
chemical_list: D016877:Oxidants; D013481:Superoxides; D030421:Peroxynitrous Acid; D009569:Nitric Oxide; D014443:Tyrosine; D013482:Superoxide Dismutase; D009584:Nitrogen
keywords: Free Radicals; Nitric Oxide; Oxidative Stress; Peroxynitrite; Superoxide Dismutase (SOD); Superoxide Ion; Tyrosine Nitration