SPECIES-SPECIFIC BETA-N-ACETYLGALACTOSAMINYLATION OF SERUM IGG PROTEINS

Lectin blot analysis of bovine, goat, human, rabbit and mouse serum im munoglobulin G (IgG) samples revealed that Wisteria floribunda aggluti nin (WFA) binds to the heavy chains of bovine, goat and human serum Ig G proteins but not those of the rabbit and mouse proteins. WFA-positiv e light chain bands were also detected in bovine, goat and human serum IgG samples only after the filters were treated with Arthrobacter ure afaciens sialidase. The WFA-binding to these IgG proteins was abolishe d by treatment of the filter with sialidase and then beta-N-acetylhexo saminidase or N-glycanase prior to incubation with the lectin. WFA-aga rose column chromatography of the oligosaccharides released by hydrazi nolysis from the IgG samples followed by reduction with (NaBH4)-H-3 re vealed that 0.15, 0.09 and 0.07% of the total oligosaccharides from bo vine, goat and human serum IgG samples bind to the column, respectivel y. Partial characterization of WFA-positive bovine IgG oligosaccharide s by Bio-Gel P-4 column chromatography suggested that the major oligos accharide is of non-fucosylated biantennary complex-type. These result s indicate that beta-N-acetylgalactosaminylation occurs to N-linked su gar chains of heavy and light chains of Ige proteins in a species-spec ific manner.