Glycopolypeptide conformations in bioactive block copolymer assemblies influence their nanoscale morphology

Abstract

We describe the preparation and assembly of glycosylated amphiphilic diblock copolypeptides, where the hydrophilic glycosylated segments adopt either α-helical or disordered conformations. In this study, glycosylated amphiphilic diblock copolypeptides were prepared using poly(l-leucine), poly(L), as the hydrophobic segment, and poly(α-d-galactopyranosyl-l-lysine), poly(α-gal-K), or poly(α-d-galactopyranosyl-l-cysteine sulfone), poly(α-gal-CO2), as the hydrophilic segment. The poly(α-gal-K) and poly(α-gal-CO2) segments are known to be fully α-helical (>90% at 20 °C) and fully disordered in water, respectively. We found that block copolypeptides containing galactosylated hydrophilic segments of either α-helical or disordered conformation give different assembly morphologies, where the disordered glycopolypeptide segments favor vesicle formation and also present sugar residues that can bind to biological targets. © 2013 The Royal Society of Chemistry.