Helix-specific properties and applications in synthetic polypeptides

Polypeptides obtained from the ring-opening polymerization of N-carboxyanhydrides, as the synthetic analogues of natural proteins, have drawn broad interests during the recent three decades. Unlike other synthetic polymers, polypeptides form ordered secondary structures like α-helices and β-sheets, which offer conformation-specific functions that are not observed in unstructured polymers. In this article, we summarized the unique structural features of α-helical polypeptides compared to their random-coiled analogues, and reviewed the helix-associated assembly behaviors and biomedical functions based on the structural differences. In addition, the characterization and modulation of polypeptide conformations were also discussed. We believe this review will shed light on the future design of synthetic polypeptides with helix-specific properties, further expanding the scope of polypeptide materials.