There are different enzymes to remove the glycans from the proteins or remove some part of the sugar chain.
* α2-3,6,8,9-Neuraminidase (from Arthrobacter ureafaciens): cleaves all non-reducing terminal branched and unbranched sialic acids.
* β1,4-Galactosidase (from Streptococcus pneumoniae): releases only β1,4-linked, nonreducing terminal galactose from complex carbohydrates and glycoproteins.
* β-N-Acetylglucosaminidase (from Streptococcus pneumoniae): cleaves all non-reducing terminal β-linked N-acetylglucosamine residues from complex carbohydrates and glycoproteins.
* endo-α-N-Acetylgalactosaminidase (O-glycosidase from Streptococcus pneumoniae): removes O-glycosylation. This enzyme cleaves serine- or threonine-linked unsubstituted Galβ1,3GalNAc
* PNGase F: cleaves asparagine-linked oligosaccharides unless α1,3-core fucosylated.