Tyrosine nitration in peptides by peroxynitrite generated in situ in a light-controlled platform: Effects of pH and thiols.

Tyrosine nitration in peptides by peroxynitrite generated in situ in a light-controlled platform: Effects of pH and thiols. J Inorg Biochem. 2014 May 9;138C:24-30 Authors: deBoer TR, Palomino RI, Idiga SO, Millhauser GL, Mascharak PK Abstract Peroxynitrite has been shown to play a critical role in inflammation and affords 3-nitrotyrosine as the hallmark product. The reported methods of generating this reactive nitrogen species in situ often fails to provide a high and steady flux of peroxynitrite resulting in poor yields of 3-nitrotyrosine. Herein we report a two-component peroxynitrite-generating platform in which this anion is produced in a biomimetic fashion and under the control of visible light. Incorporation of the nitric oxide- and superoxide-generating components in polymer matrices allows easy alterations of pH in the reaction wells of this platform. We have demonstrated very efficient nitration of tyrosine by peroxynitrite at different pH values and with varying concentrations of carbonate. In addition to tyrosine, a set of tyrosine-containing peptides was also studied. Presence of glutathione in the reaction wells increases the extent of tyrosine nitration in such peptide substrates presumably by raising the lifetime of nitric oxide in the reaction medium. When a cysteine residue was included in the sequence of the peptide, the extent of nitration of the tyrosine residue was found to depend on the position of the cysteine ...
Source: Journal of Inorganic Biochemistry - Category: Biochemistry Authors: Tags: J Inorg Biochem Source Type: research
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