Partial characterization of the acidic oligosaccharides from rat sublingual glycoprotein

Five sialic acid-containing oligosaccharides composed of nine, ten, twelve, thirteen and fifteen sugar residues, respectively, have been isolated from rat sublingual glycoprotein. Each oligosaccharide contained sialic acid, N-acetylglucosamine, N-acetylgalactosaminitol and galactose. The partial structures of desialyzed oligosaccharides, as determined by sequential degradation with specific glycosidases, are proposed to be: GlcNAc→^βGal→^βGlcNAc→^βGal→^βGlcNAc→^βGal→^βGlaNAc→^βGal→^βGlcNAc→^βGalNac-ol (oligosaccharide I), GlcNAc→^βGal→^βGlcNAc→^βGal→^βGlcNAc→^βGal→^βGlcNAc→^βGalNAc-ol (oligosaccharides II and III) and GlcNAc→^βGal→^βGlcNAc→^βGal→^βGlcNAc→^βGalNAc-ol (oligosaccharides IV and V).