2 ISOLECTINS FROM LEAVES OF WINGED BEAN, PSOPHOCARPUS-TETRAGONOLOBUS (L) DC

Two isolectins were isolated from leaves of winged bean and characteri zed. They differed from each other in terms of their immunological pro perties, hemagglutinating activities, sugar inhibition patterns, and a mino acid compositions. Both lectins were acidic and one of them (L-I) , which was inactive toward trypsinized human type O erythrocytes, was similar to one of green shell lectins (WGS-1); which resembled basic seed lectin in its immunological properties. The amino-terminal sequen ce of L-I was homologous to that of WGS-1. The amino acid composition of L-I was similar to that of basic seed lectin, but the extent of the homology between amino-terminal sequences was low when L-I and basic seed lectin were compared. Examination by ELISA revealed that L-I and WGS-1 were distinct from the basic lectins of seeds and tuberous roots . L-I had a disulfide bridge between two subunits and it exhibited hig h hemagglutinating activity toward human type A erythrocytes, as compa red to its activity toward other erythrocytes. By contrast, the proper ties of a second acidic lectin from winged bean leaves (L-II) were ver y similar to those of acidic lectins from seeds and tuberous roots, an d the similarities extended as far as the immunological properties.