Nitration of Tyrosine by Hydrogen Peroxide and Nitrite
作者:
OuryTim D.,
TatroLynn,
GhioAndrew J.,
PiantadosiClaude A.,
期刊:
Free Radical Research
(Taylor Available online 1995)
卷期:
Volume 23,
issue 6
页码: 537-547
ISSN:1071-5762
年代: 1995
DOI:10.3109/10715769509065275
出版商: Taylor&Francis
关键词: nitric oxide;superoxide;inflammation;nitrotyrosine;antioxidants
数据来源: Taylor
摘要:
Peroxynitrite anion is a powerful oxidant which can initiate nitration and hydroxylation of aromatic rings. Peroxynitrite can be formed in several ways, e.g. from the reaction of nitric oxide with superoxide or from hydrogen peroxide and nitrite at acidic pH. We investigated pH dependent nitration and hydroxylation resulting from the reaction of hydrogen peroxide and nitrite to determine if this reaction proceeds at pH values which are known to occurin vivo. Nitration and hydroxylation products of tyrosine and salicylic acid were separated with an HPLC column and measured using ultraviolet and electrochemical detectors. These studies revealed that this reaction favored hydroxylation between pH 2 and pH4, while nitration was predominant between pH 5 and pH 6. Peroxynitrite is presumed to be an intermediate in this reaction as the hydroxylation and nitration profiles of authentic peroxynitrite showed similar pH dependence. These findings indicate that hydrogen peroxide and nitrite interact at hydrogen ion concentrations present under some physiologic conditions. This interaction can initiate nitration and hydroxylation of aromatic molecules such as tyrosine residues and may thereby contribute to the biochemical and toxic effects of the molecules.
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