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.
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