A Proteomic Study of Protein Tyrosine Nitration

Protein post-translational modifications are of great interest due to their effects on protein structure and function. Our interest lays in the nitration of tyrosine residues by powerful oxidants such as peroxynitrite (ONOO-) forming 3-nitrotyrosine. The post-translational modification of tyrosine to 3-nitrotyrosine is a hallmark for protein oxidation. Traditional proteomics methods employed for the detection of nitrated peptides include SDS-PAGE, 2D-gel electrophoresis, Western blot, as well as immunoprecipitation. These are good and well accepted separation and detection methods, however they are only qualitative and don't tell us information about the specific sites of nitration. To overcome the drawbacks of these traditional proteomics methods, we have employed different methods that allowed us to perform all analytical steps in-solution. Also, we have explored the application of a novel 3-nitrotyrosine specific fluorescent, isotopic labeling technique developed in our labs for the sensitive detection and quantitation of 3-nitrotyrosine in different types of biological samples