O-LINKED NEUTRAL SUGAR CHAINS OF PORCINE ZONA-PELLUCIDA GLYCOPROTEINS

The O-linked sugar chains were liberated from porcine zona pellucida glycoproteins by alkaline-borohydride treatment and the structures of neutral oligosaccharides were determined. The major oligosaccharides had the following structures with type-1 cores, (Galbeta1 --> 4GlcNAcbeta1 --> 3)1-3-Galbeta1 --> 3N-acetylgalactosaminitol (54%) and GlcNAcbeta1 --> 3(Galbeta1 --> 4GlcNAcbeta1 --> 3)0-1Galbeta1 --> 3N-acetyl-galactosaminitol (16%). Approximately 6% of the oligosaccharides had the structure with a type-3 core, Galbeta1 --> 4GlcNAcbeta1 --> 3N-acetylgalactosaminitol. Oligosaccharides having alpha-galactose (2%) and beta-GalNAc (4%) at their non-reducing termini were also found as minor components.