Single-Chain Glycopolymer Folding via Host-Guest Interactions and Its Unprecedented Effect on DC-SIGN Binding

Reversible self-folding actions of natural biomacromolecules play crucial roles for specific and unique biological functions in Nature. Hence, controlled folding of single polymer chains has attracted significant attention in recent years. Herein, reversible single-chain folded glycopolymer structures in α-shape with different density of sugar moieties in the knot were created. The influence of folding as well as the sugar density in the knot was investigated on the binding capability with lectins, such as ConA, DC-SIGN, and DC-SIGNR. The synthesis of triblock glycocopolymers bearing β-CD and adamantane for the host-guest interaction and also mannose residues for the lectin interaction was achieved using the reversible addition-fragmentation chain transfer (RAFT) polymerization technique. The reversible single-chain folding of glycopolymers was achieved under a high dilution of an aqueous solution and the self-assembled folding was monitored by 2D nuclear overhauser enhancement spectroscopy (NOESY) NMR and dynamic light scattering. The lectin binding profiles consistently provided an unprecedented effect of single chain folding as the single-chain folded structures enhanced greatly the binding ability in comparison to the unfolded linear structures.