SMALL NEUTRAL LOSSES IN THE ELECTRON CAPTURE DISSOCIATION OF NITRATED PEPTIDES

摘要

In vivo protein nitration is associated with many disease conditions that involve oxidative stress and inflammatory response. Nitration occurs at tyrosine residues. In order to understand the mechanisms and consequences of protein nitration, it is necessary to identify nitrotyrosine-containing proteins and to localize the sites of modification. We have previously shown that the presence of 3-nitrotyrosine within a peptide sequence has a deleterious effect on electron capture dissociation (ECD) backbone cleavage [1]. That effect is particularly severe for doubly-charged precursor ions, and can be explained by the 'electron predator' model proposed by Beauchamp and co-workers [2].