Lactose-binding lectin. Also binds derivatives of galactose, glucose, lactose, and mannose. Binds O-glycoproteins such as mucins more strongly than N-glycoproteins. Shows agglutinating activity towards rabbit erythrocytes. Homotetramer. Cotyledonary membrane-bound vacuolar protein bodies. Seed. 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.