Targeting Galectin-1 with Self-Assembled Multivalent Pseudopolyrotaxanes

This review describes the development of self-assembled multivalent pseuclopolyrotaxanes as flexible and dynamic neoglycoconjugates for binding Galectin-1 (Gal-1). Gal-1, a dimeric lectin with two lactoside-binding sites, plays multiple roles in a variety of cancers. Pseudopolyrotaxanes comprised of lactoside-displaying cyclodextrin (LCD) "beads" threaded onto polyviologen "strings" display highly flexible and adaptable ligands as a result of rotation of the cyclodextrin torus about, and limited translation along, the polymer chain. The pseudopolyrotaxanes rapidly and efficiently precipitate Gal-1 and provide valency-corrected enhancements of up to 30-fold over native lactose and 20-fold over free LCD in a T-cell agglutination assay. These results show that the flexible and dynamic ligand presentation afforded by supramolecular assemblies, such as the pseudopolyrotaxanes, is a useful strategy for the study of protein-carbo hydrate interactions and the exploitation of multivalency for targeting therapeutically relevant lectins.