O-Glycosidase is used to release the Gal-β(1,3)-GaINAc unit from O-glycans (glycoproteins or glycopeptides). Bindings to serine as well as to threonine are hydrolyzed. Substituents at the disaccharide (e.g., sialic acid) prevent the hydrolysis and, therefore, have to be removed chemically or enzymatically (e.g., with neuraminidase from Arthrobacter or from Vibrio cholerae).
O-Glycosidase has been used to selectively deglycosylated chondroitin sulfate proteoglycans (CSPGs).
O-Glycan-peptide hydrolase
O-Glycopeptide endo-D-galactosyl-N-acetyl-α-galactosamino hydrolase
O-Glycosidase is isolated from the culture filtrate of Diplococcus pneumoniae
Releases unsubstituted Ser- and Thr-linked β-Gal-(1→3)-α-GalNAc (Core 1 type O-glycan) from glycoproteins. Substitutions of the disaccharide core with sialic acid, lactosamine (galactose-N-acetyl glucosamine), or fucose will block hydrolysis and prevent the liberation of the oligosaccharide from the protein. Pretreament with glycolytic enzymes to remove substituent saccharides from the O-glycan may be needed prior to cleavage using O-glycosidase..
