Pulse radiolysis and mass spectrometry study on the one electron oxidation of 3-nitrotyrosine and its derivatives

Lin, M.; Shi, W.*; Fu, H.*; Muroya, Yusa*; Katsumura, Yosuke; Xu, D.*; Chai, Z.*

The reaction between reactive nitrogen species (RNSs) such as peroxynitrite and nitrogen oxide (NOx), and aromatic amino acids such as tyrosine and tryptophan results in a number of modifications, of which tyrosine nitration has gained much attention. 3-Nitrotyrosine (3-NT) was considered as an important biomarker of nitrative stress . In this work, the reaction rate constants of 3-NT, N-acetyl-3-nitrotyrosine ethyl ester (NANTE) and 3-NT containing peptide Gly-nitroTyr-Gly reacting with azide radical (N) at pH 6.0 were measured. The UV-visible absorption spectra of the transients of N reacting with the above compounds were also investigated. The results implied the possibility of protein aggregation through covalent dimerization of 3-NT residue .