Studies of the molecular recognition of synthetic methyl β-lactoside analogues by Ricinus communis agglutinin

Abstract

The 2-, 3-, 6-, 2′-, 3′-, 4′-, and 6′-deoxy derivatives and the 3- O-methyl derivative of methyl β-lactoside have been synthesised and their binding to the galactose-specific agglutinin from Ricinus communis (RCA-120) has been investigated. The results indicate that HO-3,4,6 of the β- d-galactopyranose moiety are the key polar groups. The main difference from the closely related ricin lectin RCA-60 involves HO-6 of the d-glucopyranose moiety, which seems to contribute to the binding of the carbohydrate to RCA-60 but not to RCA-120.