Topological Glycopolymers as Agglutinator and Inhibitor: Cyclic versus Linear.

Carbohydrates play an important role in biological processes for their specific interactions with proteins. Cyclic glycopolymers are promising to mimic the topology of natural macrocycle-biomacromolecules due to their unique architecture of lacking chain ends. To systematically study the effect of glycopolymer architecture on the interactions with protein, the cyclic glycopolymers bearing galactose side-chain (cyclic PMAGn ) with three degrees of polymerization (n = 14, 24, 47) are prepared for the first time. The cyclic PMAGn exhibits unique properties in agglutinating and inhibiting proteins in subsequent studies by comparison with the linear precursor with the same molecular weights. More impressively, the cyclic PMAGn highlight the improved performance of cyclic architecture. For example, the cyclic PMAGn shows superior inhibition abilities to suppress amyloid formation from amyloid β protein fragment 1-42 aggregation and block the specific interaction between bacteria and galactose-modified surface compared to that of respective linear counterpart. This interesting finding suggests that the architecture of cyclic glycopolymers may be capable of optimizing the ability to bind or inhibit proteins in biological processes.