Removal of glycan groups from proteins via enzymatic methods is preferable to chemical removal because it is gentler and can provide complete sugar removal with no protein degradation.
Endoglycosidases cleave entire glycan groups from glycoproteins. The most commonly used endoglycosidase, Peptide-N-Glycosidase F (PNGase F) (NEB #P0704, NEB #P0703), and catalyzes the deglycosylation of most N-linked glycoproteins. The enzyme catalyzes the cleavage between the innermost N-Acetylglucosamine (GlcNAc) and the amine group of the asparagine residue (1).
Not all endoglycosidases have identical cleavage sites. Endoglycosidase H (Endo H) (NEB #P0702, NEB# P0703) cleaves within the chitobiose core of high mannose and some hybrid oligosaccharides from N-linked glycoproteins (1). The enzyme also cleaves some asparagine-linked hybrid glycans. O-Glycosidase (NEB #P0733, NEB #E0540), also called α-N-Acetylgalactosaminidase, is used to catalyze the removal of Core 1 (Galβ1,3GalNAc) or Core 3 (GlcNAcβ1,3GalNAc) O-linked disaccharides.
- Maley, F. et al. (1989) Anal. Biochem., 180, 195-204. PMID: 2510544
- Koutsioulis, D., Landry, D. and Guthrie, E.P. (2008) Glycobiology, 18, 799-805. PMID: 18635885