This lectin is a dimeric glycoprotein composed of two subunits of nearly identical size with each subunit having disulfide-linked chains and a binding site for α- or β-linkedN-acetylglucosamine residues. Unlike other N-acetylglucosamine specific lectins, increasing the number of N-acetylglucosamine residues beyond two does not improve affinity. GSL II has been reported to be unique in its ability to recognize exclusively α- or β-linked N-acetylglucosamine residues on the nonreducing terminal of oligosaccharides.