O-Glycans are linked to the –OH of serine or threonine in peptides and proteins. O-Glycans linked via N-acetylgalactosamine (GalNAc), such as those in mucins, can have a variety of core structures. We offer kits for the removal of O-glycans as well as standards for O-linked blood group and milk glycans.
Our GK80110 Enzymatic Deglycosylation Kit contains Sialidase A and O-Glycanase, and these enzymes can be purchased separately as GK80040 and GK80090. The Kit also contains PNGAse F (GKE-5006). Enzymatic removal of O-glycans is a tough problem – there is not a single enzyme that can remove the majority of O-glycan structures in the same way that PNGase F can remove many N-glycans. O-Glycanase (GK80090) will only cleave Gal-GalNAc-O-Ser/Thr. If there are other sugars that make up an O-glycan structure, they have to be cleaved off with other enzymes to reveal Gal-GalNAc (core 1) before O-Glycanase will work. We include Sialidase A in the GK80110 kit to remove terminal sialic acid to reveal core 1, and the GK80115 extender (β(1-4)Galactosidase & β-N-Acetylglucosaminidase) can help with e.g. core 2 structures (GlcNAc-(Gal)-GalNAc-S/T).
The GK50202 Glycan Hydrazinolysis Kit chemically releases N- and O-glycans. Cleavage of peptide bonds occurs, therefore hydrazinolysis should not be used when recovery of the protein is desired.
Glycoproteins may be deglycosylated with trifluoromethanesulfonic acid (TFMS) using the GKK-500 Chemical Deglycosylation Kit. The innermost monosaccharide (e.g. GlcNAc-Asn, GalNAc-Ser/Thr) of glycans attached to the polypeptide are not cleaved under the conditions used. The process degrades oligosaccharides, so information regarding glycan structure may not be obtained.