Chip-based CE coupled to a quadrupole TOF mass spectrometer for the analysis of a glycopeptide.

A novel approach using sheath flow chip-based CE coupled to a quadrupole TOF mass spectrometer was developed and applied to the analysis of an O-glycopeptide. The method provided good separation and sensitive analysis of the glycopeptide and its beta-elimination product. The beta-elimination reaction of the glycopeptide with ammonia or dimethylamine was adapted for changing the glycopeptide into deglycosylated form and for specifying the site of glycosylation. MS/MS analysis of the native peptide, glycopeptide and beta-elimination product enabled the identification of the glycosylation site through the comparison of the fragmentations and peptide sequence analysis.