Facile Preparation of a Glycopolymer Library by PET-RAFT Polymerization for Screening the Polymer Structures of GM1 Mimics

Commercialized oligosaccharides such as GM1 are useful for biological applications but generally expensive. Thus, facile access to an effective alternative is desired. Glycopolymers displaying both carbohydrate and hydrophobic units are promising materials as alternatives to oligosaccharides. Prediction of the appropriate polymer structure as an oligosaccharide mimic is difficult, and screening of the many candidates (glycopolymer library) is required. However, repeating polymerization manipulation for each polymer sample to prepare the glycopolymer library is time-consuming. Herein, we report a facile preparation of the glycopolymer library of GM1 mimics by photoinduced electron/energy transfer-reversible addition-fragmentation chain-transfer (PET-RAFT) polymerization. Glycopolymers displaying galactose units were synthesized in various ratios of hydrophobic acrylamide derivatives. The synthesized glycopolymers were immobilized on a gold surface, and the interactions with cholera toxin B subunits (CTB) were analyzed using surface plasmon resonance imaging (SPRI). The screening by SPRI revealed the correlation between the log P values of the hydrophobic monomers and the interactions of the glycopolymers with CTB, and the appropriate polymer structure as a GM1 mimic was determined. The combination of the one-time preparation and the fast screening of the glycopolymer library provides a new strategy to access the synthetic materials for critical biomolecular recognition.