Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail, Toronto, M1C 1A4, Canada.
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada.
Angew Chem Int Ed Engl. 2017 Oct 16;56(43):13288-13292. doi: 10.1002/anie.201706162. Epub 2017 Sep 21.
Homochirality in peptides is crucial in sustaining "like-like" intermolecular interactions that allow the formation of assemblies and aggregates and is ultimately responsible for the resulting material properties. With the help of a series of stereoisomers of the tripeptide F-F-L, we demonstrate the critical role that peptide stereochemistry plays in the self-assembly of peptides, guided by molecular recognition, and for self-sorting. Homochiral self-assemblies are thermally and mechanically more robust compared to heterochiral self-assemblies. Morphological studies of the multicomponent peptide systems showed that aggregates formed from homochiral peptides possessed a uniform nano-fibrous structure, whereas heterochiral systems resulted in self-sorted systems with a heterogeneous morphology. In essence, homochiral peptides form the stronger aggregates, which may be one of reasons why homochirality is preferred in living systems.
手性在肽中至关重要，它维持着“相似-相似”的分子间相互作用，从而允许组装体和聚集体的形成，并最终决定了所得材料的性质。在一系列三肽 F-F-L 的立体异构体的帮助下，我们展示了肽立体化学在手性肽的分子识别引导下自组装以及自分类中的关键作用。与手性肽自组装相比，手性肽自组装具有更好的热稳定性和机械稳定性。多组分肽体系的形态研究表明，由手性肽形成的聚集体具有均匀的纳米纤维结构，而手性体系则导致具有异质形态的自分类体系。从本质上讲，手性肽形成更强的聚集体，这可能是手性在生命系统中受到偏好的原因之一。
