Isolation from Rubus cell-suspension cultures of a lectin specific for glucosamine oligomers

A lectin specific for glucosamine oligomers has been purified by chitosan affinity chromatography from cultured cells of Rubus. The lectin, eluted by a glucosamine oligomer of degree of polymerization 4 in the presence of l-α-phosphatidylserine dipalmitoyl, was found by sodium dodecyl sulfate-polyacrylamide gel electroploresis to be homogeneous and to have a molecular weight of 67 kilodaltons; it could best bind the tetrasaccharide, as shown by ligand-blot processing. Data from kinetic-dependent enzyme-linked immunosorbent assays showed that the lectin has two apparent binding sites which better accommodate the tetrasaccharide and the hexasaccharide, respectively, of the glucosamineoligomer series. The affinity of the lectin for glucosamine oligomers was shown to decrease for chain lengths greater than six glucosaminyl residues.