Mapping O-GlcNAc and Phosphorylation Sites in C-MYC and CTD Peptides by Electron Transfer Dissociation Mass Spectrometry

[steve-day]

Modification of Serine/Threonine residues on peptides by phosphorylation or addition of a single O–linked N–acetylglucosamine (O–GlcNAc) plays an important role in cell regulation. In many instances, the sites of O–GlcNAcylation or phosphorylation are localized to the same, or neighboring residues on the peptide. Both modifications are extremely dynamic and labile, making them difficult to analyze by traditional mass spectrometry fragmentation techniques such as Collisionally Induced Dissociation (CID).