A novel monoantennary complex-type sugar chain found in octopus rhodopsin: occurrence of the Galβ1→4Fuc group linked to the proximal <i>N</i>-acetylglucosaniine residue of the trimannosyl core

Abstract

The N-linked sugar chains were liberated as oligosaccha-rides from octopus rhodopsin by hydrazinolysis. Most of the oligosaccharides were neutral, and separated into two major components by column chromatography using immobilized lectins and Bio-Gel P-4. Structural analysis of the one major component by sequential exoglycosidase digestion, chemical fragmentation in combination with meth-ylation analysis revealed that it is a nonasaccharide; Manα1→6(Gaiβ1→3GlcNAcβ1→2Manα1→3)Manβ1→4GlcNAcβ1→4(Galβ1→4Fucα1→6)GlcNAc This structure is quite unique in that a novel galactosylated fucose residue is attached to the reducing terminal N-acetyl-glucosamine residue.