PNNL

Abstract

A long-standing challenge in bioinspired materials is to design and synthesize synthetic materials that mimic the sophisticated structures and functions of natural biomaterials, such as helical protein assemblies with the extreme importance in biological systems. Herein, we report the formation of a series of nanohelices from a type of well-developed protein-mimetics called peptoids. We demonstrated that nanohelix structures and supramolecular chirality can be well-controlled through the side-chain chemistry. Specifically, the ionic effects on peptoids with varying the hydrophilic side-chain groups result in the formation of either single helical fibers or hierarchically stacked helical bundles. We also demonstrated that the supramolecular chirality of assembled peptoid helices could be controlled by modifying assembling peptoids with a single chiral amino acid side chain. Computational simulations and theoretical modeling predict that minimizing exposure of hydrophobic domains within a twisted helical form presents the most thermodynamically favorable packing of these amphiphilic peptoids and suggests a key role for both hydrophilic and hydrophobic domains on nanohelix formation. Our findings establish a new platform to design and synthesize chiral functional materials using sequence-defined synthetic polymers.