Jacalin interacts with Asn-linked glycopeptides containing multi-antennary oligosaccharide structure with terminal alpha-linked galactose.

The carbohydrate binding properties of jacalin lectin were examined using RAF9 cell-derived D-[6-3H]glucosamine-radiolabeled total glycopeptides containing N-linked and O-linked oligosaccharides. The binding of N-linked glycopeptides to jacalin was abolished by treatment of alpha-galactosidase whereas O-linked glycopeptides were still bound lectin after this treatment. The removal of O-linked oligosaccharides by mild alkaline/borohydride treatment completely eliminated the lectin binding of alpha-galactosidase treated glycopeptides. These results demonstrate that jacalin interacts with cellular glycopeptides containing N-linked oligosaccharides with terminal alpha-galactose residues as well as glycopeptides containing O-linked oligosaccharides.