Birner-Gruenberger_2015_Chem.Biol_22_315

Posttranslational modifications (PTMs) control protein function, but established peptide-based proteomic methods often fail to provide a comprehensive view of PTMs. In this issue of Chemistry & Biology, Gersch et al. describe an efficient combination of chromatographic separation and top-down mass spectrometry that together with an intuitive visualization tool allowed them to screen the proteasome for PTMs and covalently binding inhibitors.