Endo-ñ-N-acetylgalactosaminidase (, endo-ñ-acetylgalactosaminidase, endo-ñ-N-acetyl-D-galactosaminidase, mucinaminylserine mucinaminidase, D-galactosyl-3-(N-acetyl-ñ-D-galactosaminyl)-L-serine mucinaminohydrolase, endo-ñ-GalNAc-ase, D-galactosyl-N-acetyl-ñ-D-galactosamine D-galactosyl-N-acetyl-galactosaminohydrolase) is an enzyme with systematic name glycopeptide-D-galactosyl-N-acetyl-ñ-D-galactosamine D-galactosyl-N-acetyl-galactosaminohydrolase. This enzyme catalyses the following chemical reaction
The enzyme catalyses the release of Gal-(1->3)-beta-GalNAc alpha-linked to serine or threonine residues of mucin-type glycoproteins.
Glycopeptide ñ-N-acetylgalactosaminidases belong to family GH101 of glycoside hydrolases.