A novel beta-N-acetylglucosaminidase activity in hog gastric mucosal microsomes: preferential hydrolysis of terminal GlcNAc beta 1-3 linkages in GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc, but GlcNAc beta 1-6 linkages in GlcNAc beta 1-3(GlcNAc beta 1-6)Gal.
Hog gastric mucosal microsomes contain beta-N-acetylglucosaminidase activity which cleaves GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc at the terminal GlcNAc beta 1-3Gal linkage faster than at the GlcNAc beta 1-6Gal bond, producing mainly GlcNAc beta 1-6Gal beta 1-4GlcNAc. In a marked contrast, GlcNAc beta 1-3(GlcNAc beta 1-6)Gal is cleaved primarily at the GlcNAc beta 1-6Gal bond, while partial hydrolysis of GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4Glc reveals similar rates of cleavage for the (1-3) and (1-6) linkages. Our data support the notion that the terminal beta 1,6-linked GlcNAc unit of GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc may interact with the reducing end GlcNAc unit intramolecularly in water solution.
Helin
J
J
Department of Biochemistry, University of Helsinki, Finland.
Seppo
A
A
Leppänen
A
A
Penttilä
L
L
Maaheimo
H
H
Niemelä
R
R
Lauri
S
S
Renkonen
O
O
D000118:Acetylglucosaminidase / Q000378:metabolism*; D000818:Animals; D002240:Carbohydrate Sequence; D005753:Gastric Mucosa / Q000201:enzymology*; D006868:Hydrolysis; D066298:In Vitro Techniques; D008861:Microsomes / Q000201:enzymology*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000378:metabolism*; D013552:Swine; D014312:Trisaccharides / Q000378:metabolism*
D009844:Oligosaccharides; D014312:Trisaccharides; C064589:N-acetylglucosaminyl(beta1-3)-N-acetylglucosaminyl(1-6)-galactopyranosyl(1-4)-N-acetylglucosamine; C064588:N-acetylglucosaminyl(1-3)-N-acetylglucosaminyl(1-6)-galactopyranose; D000118:Acetylglucosaminidase