作者: Jacinda B. Sampson , YaoZu Ye , Henry Rosen , Joseph S. Beckman
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摘要: Abstract Nitration of tyrosine residues in proteins occurs a wide range inflammatory diseases involving neutrophil and macrophage activation. We report that both myeloperoxidase (MPO) horseradish peroxidase (HRP) utilize nitrite (NO 2 − ) hydrogen peroxide (H O as substrates to catalyze nitration proteins. MPO was approximately 10 times more effective than HRP catalyst bovine serum albumin (BSA). BSA by did not require chloride cofactor. Physiologic levels significantly inhibit MPO. Oxidation hypochlorous acid (HOCl) is catalyzed but HRP, yet also from plus nitrite. Therefore, HOCl formation obligatory for nitration. Although can nitrate the amino simple solutions, protein observed heart homogenates, probably due presence multiple alternative targets In contrast, many rat homogenates using NO H , suggesting peroxidase-catalyzed could occur competing vivo. substitute oxidizing substrate either or tissue peroxidase. Activated neutrophils may generate nitrotyrosine several mechanisms, including peroxynitrite, nitrite, chloride-independent mechanism MPO, peroxide.