Laser-induced photofragmentation of neutral and acidic glycans inside an ion-trap mass spectrometer.

ABSTRACT

Permethylated acidic and neutral N-glycans representing different types of glycan structures, such as linear and branched sialylated structures, high-mannose type and fucosylated complex type, were photodissociated with 157 nm vacuum ultraviolet light in a linear ion trap. Cross-ring fragments corresponding to high-energy fragmentation pathways were observed in abundance for all studied structures. Some product ions appear diagnostic for a linkage of sialic acid residues and the glycan antenna to which these residues are attached. A conclusive assignment of the fucosylation site of the studied glycan structure has been facilitated through measurement of cross-ring fragmentation resulting from photodissociation.