The Hunt lab weighs in on mass spectrometry-based analysis of protein post-translational modifications.

Protein post-translational modifications have traditionally been challenging to identify due to their dynamic regulation and typically low stoichiometry. Methods for phosphopeptide enrichment from complex proteomes developed in the Hunt lab in the late 1990's and early 2000's launched the field of phosphoproteomics, the large-scale analysis of protein phosphorylation sites. To improve phosphopeptide tandem mass spectra and address the further challenge of identifying other labile PTMs such as glycosylation or tyrosine sulfation, the Hunt lab invented and disseminated electron transfer dissociation (ETD), a novel method for peptide and protein fragmentation. Here we provide a brief historical accounting of these discoveries and their ensuing applications.