Composition of the acidic fraction of O-glycans released from PGM.

Monosaccharide composition of individual glycans was established by MALDI-TOF-MS based on the m/z values of monosaccharides.Nature of monosaccharides (Gal, GlcNAc and Fuc) was based on GC composition analysis and on previous reports [48]. m/z values of sialylated glycans correspond to [M+Na]+ adducts whereas sulphated glycans exhibited [M+2Na-H]+ adducts.