Rhamnose-binding lectin. Also binds alpha-D-melibiose, alpha-D-lactose, beta-D-lactose, methyl-alpha-D-galactopyranoside, methyl-beta-D--galactopyranoside and D-galactose but not D-arabinose, L-fucose, D-glucose, D-mannose, D-maltose, D-sucrose, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, N-acetyl-D-mannosamine-D-xylose or by glycoproteins orosomucoid, thyroglobulin, ovomucoid and porcine stomach mucin. Shows cation-independent hemagglutinating activity against rabbit and human erythrocytes. Agglutinates cells of Gram-positive bacterial species S.aureus but not those of Gram-negative E.coli. Activity is stable between pH 4 and 7 but decreases at basic pH. Activity is stable up to 60 degrees Celsius, then decreases and is lost at 100 degrees Celsius. Homodimer; disulfide-linked. Not glycosylated. Homodimer.