Nitration of tyrosine by hydrogen peroxide and nitrite.

Published

Journal Article

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 occur in vivo. Nitration and hydroxylation products of tyrosine and salicyclic 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 pH 4, 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.

Full Text

Duke Authors

Cited Authors

  • Oury, TD; Tatro, L; Ghio, AJ; Piantadosi, CA

Published Date

  • December 1995

Published In

Volume / Issue

  • 23 / 6

Start / End Page

  • 537 - 547

PubMed ID

  • 8574348

Pubmed Central ID

  • 8574348

Electronic International Standard Serial Number (EISSN)

  • 1029-2470

International Standard Serial Number (ISSN)

  • 1071-5762

Digital Object Identifier (DOI)

  • 10.3109/10715769509065275

Language

  • eng