Isolation of glycopeptides from the lectin-stimulated human peripheral lymphocyte cell surface.

Three radioactive glycopeptides were isolated from human peripheral lymphocytes stimulated with Wistaria floribunda mitogen in the presence of D-[14C]glucosamine hydrochloride by mild trypsin digestion followed by gel filtration and preparative high-voltage paper electrophoresis. The carbohydrate compositions of these glycopeptides suggest that one has a sugar chain of the type found in serum glycoproteins, consisting of sialic acid, galactose, N-acetylglucosamine, mannose, and fucose in a molar ratio of 2:2:4:2:1, and the other two have sugar chains like those of mucins, consisting of sialic acid, galactose, and N-acetylgalactosamine in a molar ratio of 1 or 2:1:1. The results of enzymic degradation with purified glycosidases indicate that these sugar chains are similar in structure to their counterparts in human erythrocyte membranes.