Quantitative Characterization of protein post-translational modifications using mass spectrometry

Post-translational protein modifications such as phosphorylation and oxidative modifications play essential roles in the regulation of a variety of biological processes. Increasing evidence suggests that changes in protein modifications over time correlate with particular phenotypes and disease states. However, quantitative characterization of protein modifications still presents a tremendous challenge for current analytical technologies due to the extremely low abundance of modified proteins among very complex proteome samples. This project is directed towards developing global proteomic approaches for more sensitive and comprehensive characterization of modified proteins. Specifically, we will focus on the development of a quantitative proteomic approach for analyzing protein phosphorylation and oxidative protein modifications, including tyrosine nitration and methionine oxidation. Specific enrichment methodologies for these modified peptides will be one of the keys to the success for this project.