SPR study for analysis of a water-soluble glycopolymer interface and molecular recognition properties

Glycopolymers consisting of mannose and acrylamide with different mannose incorporation ratios (10 and 100%) were synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization, and the polymer layers were prepared on a gold substrate. The detailed polymer layer structure and molecular recognition properties were analyzed by the surface plasmon resonance (SPR) technique. The glycopolymers formed pancake-like thin layers with thicknesses of ∼2 nm in air and were swollen in the aqueous solution. The molecular recognition against concanavalin A (ConA) was also analyzed by SPR. Binding constants between glycopolymers and ConA were large enough to suggest multivalent effects. Binding rate constants of ConA to glycopolymers were in the same order; however, the dissociation rate constant was lower in the glycopolymer with a mannose ratio of 100% because of the high local mannose density near the binding point of ConA.