Specificities of Ricinus communis agglutinin 120 interaction with sulfated galactose

► Carbohydrate arrays were used to investigate RCA120 interaction with galactose. ► Sulfated galactose-containing probes were prepared from marine-derived galactans. ► RCA120 binding to galactose was enhanced by 2-O- or 6-O-sulfation. ► RCA120 binding to galactose was abolished by 4-O-sulfation. ► Erythrina cristagalli lectin cannot accommodate any sulfation on terminal galactose.