Zhang Gong, Liang Yaoyu, Wang Yuefei, Li Qing, Qi Wei, Zhang Wei, Su Rongxin, He Zhimin
School of Chemical Engineering and Technology, State Key Laboratory of Chemical Engineering, Tianjin University, Tianjin 300072, People's Republic of China.
State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou Industrial Park, Suzhou 215123, People's Republic of China.
ACS Nano. 2022 Apr 26;16(4):6866-6877. doi: 10.1021/acsnano.2c01912. Epub 2022 Mar 23.
Chiral regulation to prepare functional materials has aroused considerable interest in recent years. However, little is known on the effect of chirality of ligands in the metal-organic coordination assembly process. We report the self-assembly of diphenylalanine peptide (Phe-Phe, FF), the core fragment of Aβ protein, with metal copper ion (Cu) into metal-organic assemblies with chirality-encoded structures and properties. The chirality-dependent metal-dipeptide assembles with different morphologies and supramolecular chirality were obtained by facile changing of the FF chirality. Single-crystal results indicate that (L)-FF coordinated with Cu into a cross-chain structure with a five-coordinated style, while the racemates of (L+D)-FF with Cu crystallized into an (L)-Cu-(D)-Cu alternated four-coordinating structure, enabling a higher mechanical and catalytic performance. The Young's modulus of (L+D)-FF-Cu is as high as 34.36 GPa, which is 2.45 times higher than that of (L)-FF-Cu. Furthermore, both of them follow the characteristic enzyme kinetics and show higher catalytic activity than natural laccase at the same mass concentration. Specifically, the calculated catalytic efficiency (/) of (L+D)-FF-Cu is 1.14 times higher than that of (L)-FF-Cu, and the (L+D)-FF-Cu shows significantly enhanced stability and reusability compared with (L)-FF-Cu. The results reveal that highly functional materials could be constructed by encoding the chirality of molecular building blocks.
近年来，通过手性调控来制备功能材料引起了广泛关注。然而，关于配体手性在金属有机配位组装过程中的影响却知之甚少。我们报道了β-淀粉样蛋白（Aβ）的核心片段二苯基丙氨酸肽（Phe-Phe，FF）与金属铜离子（Cu）自组装形成具有手性编码结构和性质的金属有机组装体。通过简单改变FF的手性，获得了具有不同形态和超分子手性的手性依赖型金属 - 二肽组装体。单晶结果表明，（L）-FF与Cu配位形成具有五配位方式的交叉链结构，而（L + D）-FF与Cu的外消旋体结晶形成（L）-Cu-（D）-Cu交替的四配位结构，从而具有更高的机械性能和催化性能。（L + D）-FF-Cu的杨氏模量高达34.36 GPa，是（L）-FF-Cu的2.45倍。此外，它们都遵循特征酶动力学，并且在相同质量浓度下比天然漆酶表现出更高的催化活性。具体而言，（L + D）-FF-Cu的计算催化效率（/）比（L）-FF-Cu高1.14倍，并且与（L）-FF-Cu相比，（L + D）-FF-Cu显示出显著增强的稳定性和可重复使用性。结果表明，通过编码分子构建块的手性可以构建高功能材料。
