Self-assembled chiral nanostructures of amphiphilic peptide: from single molecule to aggregate

We report interesting hierarchical self-assembled architectures from a designed amphiphilic peptide. The bisignate cotton effects in circular dichroism spectra show typical peptide aggregation-induced. The observation of peptide assembly structures from initial particles and fibrils to ribbon structures is supported by microscopy (atomic force microscopy and transmission electron microscopy). The visualization of individual peptide at the single molecular level offered insights of the intermolecular interactions responsible for the formation of aggregates, which is investigated by scanning tunneling microscopy. The orientation of intermolecular bonds between carboxylic and amine group and the hydrophobic interactions between alanine residues could be the dominant driving force for the assembly chirality at near-neutral pH. The single molecular and aggregate level evidence in this manuscript will shed light on the understanding of hierarchical chiral self-assembly pathway and the underlying mechanism. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.