Hemagglutinating activity of Dolichos lablab seed protein

The hemagglutinating activity of a crude extract and partially purified protein fractions from seeds of Dolichos lablab grown in the state of Bahia, Brazil, has been examined. The crude extract agglutinates rabbit erythrocytes non-specifically with respect to blood groups. The hemagglutination of rabbit erythrocytes induced by the crude extract of D. lablab was inhibited most effectively by N-acetyl-D-glucosamine (3 mM) and alpha-methyl-D-mannoside (3 mM) followed by D-glucosamine (6 mM), D-mannose (6 mM) and D-glucose (12 mM). The spectrum of sugar inhibition of the hemagglutinating activity of the Brazilian seeds combines the characteristics of seeds coming from Turkey and India as indicated by the preferential inhibitory effect exerted by N-acetyl-D-glucosamine and the inhibition by D-mannose and D-glucose. These data suggest that the Brazilian seeds may belong to a different variety of Dolichos lablab.