Controlled synthesis of glycopolymers with pendant complex-type sialylglycopeptides and their binding affinity with a lectin and an influenza virus

Glycopolymers bearing complex-type sialylglycopeptides (SGPs) were synthesized using polymers with pendant-activated esters, poly(N-succinimidyl acrylate)s (polyNSAs), and SGP in which N-acetylneuraminic acids were presented at the nonreducing ends. The SGP-grafted copolymers were synthesized successfully by post-polymerization modification of an amino group of SGP with N-succinimidyl esters on the polyNSAs, with different degrees of polymerization (DPs) and degrees of substitution (DSs) of SGP. The resulting glycopolymers bearing SGPs exhibited strong interaction with the corresponding lectin Sambucus sieboldiana agglutinin with higher association constant (Ka) values of the order of 107 M−1. Moreover, the glycopolymers bearing SGPs interacted strongly with the human influenza A virus because of the multivalency of the oligosaccharide moieties on the polymer backbone. Their binding affinities increased with increasing DP and DS of SGP. The glycopolymers did not potentially induce cytotoxicity in the cells.