Protein-carbohydrate interactions exhibit myriad intracellular recognition events, so understanding and investigating their specific interaction with high selectivity and strength are of crucial importance. In order to examine the effect of multivalent binding on the specificity of protein-carbohydrate interactions, we synthesized mannose glycosides as a novel type of glycosylated monomer and glycopolymers of polyacrylamide derivatives with α-mannose (α-Man) by radical polymerization and monitored their strength of interaction with concanavalin A (Con A) by surface plasmon resonance (SPR) detection. In a quantitative test using the Con A-immobilized sensor surface, the kinetic affinity for the synthesized polymers, 8a (KD = 3.3 × 10-6 M) and 8b (KD = 5.3 × 10-5 M), were concentration-dependent, showing strong, specific molecular recognition abilities with lectin. Our study showed the enhancement in recognition specificity for multivalent saccharides, which is often mediated by cell surface carbohydrate-binding proteins that exhibit weak affinity and broad specificity for the individual ligands.
Keywords: concanavalin A; glycopolymers; kinetic affinity; mannose; radical polymerization; surface plasmon resonance.