Dr. Amy Ham, assistant professor of pharmacy, was recently informed that her manuscript, “Label-Free Quantitation of Protein Modifications by Pseudo-Selected Reaction Monitoring with Internal Reference Peptides,” was accepted for publication in the American Chemical Society’s Journal of Proteome Research. Dr. Ham and her team describe a method using an ion trap mass spectrometer for label-free quantitation of protein modifications using a targeted MS/MS approach with extraction of transition ions for pseudo-selective reaction monitoring (pSRM) and the use of non-modified peptides within the same protein of interest for normalization. The utility of the method was demonstrated by comparing this approach to the more traditional use of stable-isotope dilution (SID) using the well-studied phosphorylation of epidermal growth factor receptor (EGFR) as an example that could also be verified by commonly used western blot analysis using site-specific antibodies.
