D-mannose/D-glucose-binding lectin. Has hemagglutinating activity towards rabbit erythrocytes. Optimum pH is 6-8 for hemagglutinating activity. Activity is reduced to 50% at pH 8.5. Homotetramer. The beta and gamma chains are produced by partial proteolytic processing of the lectin alpha chain by an asparaginyl endopeptidase. Mixture of 60% alpha lectin and 40% of its beta and gamma proteolytic fragments. Alpha chain. Beta chain. Gamma chain. Binds one manganese (or another transition metal) ion and one calcium ion. The metal ions are essential for the saccharide-binding and cell-agglutinating activities. Belongs to the leguminous lectin family.