State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , P.R. China.
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, School of Biotechnology , Tianjin University of Science and Technology , Tianjin 300457 , P.R. China.
ACS Nano. 2018 Dec 26;12(12):12305-12314. doi: 10.1021/acsnano.8b06173. Epub 2018 Nov 26.
Self-assembly of peptides and amyloid fibrils offers an appealing approach for creating chiral nanostructures, which has promising applications in the fields of biology and materials science. Although numerous self-assembled chiral materials have been designed, the precise control of their twisting tendency and their handedness is still a challenge. Herein, we report the self-assembly of chiral nanostructures with precisely tailored architectures by changing the amino acid sequences of the peptides. We designed a series of self-assembling tripeptides bearing different l-amino acid sequences. The peptide with l-Phe-l-Phe sequence preferred to self-assemble into left-handed nanohelices, while with l-Phe-l-Trp right-handed nanohelices would be formed. Moreover, the diameter of the self-assembled nanohelices could be tailored by changing the terminal amino acids (His, Arg, Ser, Glu, and Asp). Circular dichroism (CD) and molecular dynamics simulations (MDSs) revealed that both of the right- and left-handed nanohelices formed by the tripeptides showed negative Cotton effects in the peptide adsorption region but exhibited nearly opposite CD Cotton effects in the aromatic regions. These results indicated that the handedness of the self-assembled helical nanofibers was not only determined by the chirality of the peptide backbone but also closely related to the aromatic stacking, hydrogen bonding and steric interactions induced by the side chains. The findings deepen our understanding on the chiral self-assembly of peptide and offer opportunities for the creation of highly functional chiral nanomaterials.
多肽和淀粉样纤维的自组装为构建手性纳米结构提供了一种有吸引力的方法，在手性纳米材料的生物学和材料科学领域具有广阔的应用前景。尽管已经设计出了许多自组装的手性材料，但精确控制它们的扭曲趋势和手性仍然是一个挑战。在此，我们通过改变肽的氨基酸序列，报道了通过精确调整结构来自组装手性纳米结构的方法。我们设计了一系列带有不同 l-氨基酸序列的自组装三肽。带有 l-Phe-l-Phe 序列的肽倾向于自组装成左手纳米螺旋，而带有 l-Phe-l-Trp 序列的肽则会形成右手纳米螺旋。此外，通过改变末端氨基酸（His、Arg、Ser、Glu 和 Asp），可以调整自组装纳米螺旋的直径。圆二色性（CD）和分子动力学模拟（MDSs）表明，三肽形成的右手和左手纳米螺旋在肽吸附区均表现出负的 Cotton 效应，但在芳香区表现出几乎相反的 CD Cotton 效应。这些结果表明，自组装螺旋纳米纤维的手性不仅取决于肽主链的手性，还与侧链诱导的芳香堆积、氢键和空间相互作用密切相关。这些发现加深了我们对手性肽自组装的理解，为创造具有高功能的手性纳米材料提供了机会。
