Beta-galactoside lectin that agglutinates rabbit and human erythrocytes in a calcium-dependent fashion (MHC is 0.21 ug/ml on rabbit erythrocytes). Galactose (15 mM), lactose (20 mM), rhamnose (20 mM) and EGTA strongly inhibit this activity. Homodimer; disulfide-linked. Expressed by the venom gland. Belongs to the true venom lectin family.