Graduate School of Engineering, Yokohama National University, Hodogaya-ku, Yokohama 240-8501, Japan.
Department of Chemistry, Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japan.
Phys Chem Chem Phys. 2019 Jun 7;21(21):10879-10883. doi: 10.1039/c9cp00233b. Epub 2019 Apr 10.
Self-assembling phenylalanine-based peptides have garnered interest owing to their potential for creating new functional materials. Here, we designed four diastereomers, l-Phe-l-Phe-l-Phe (FFF), d-Phe-l-Phe-l-Phe (fFF), l-Phe-d-Phe-l-Phe (FfF) and l-Phe-l-Phe-d-Phe (FFf), to analyze the effect of the d-isomer on the self-assembly. Using SEM, TG, VCD, and solid-state NMR measurements, we found that only FFf forms a γ-turn conformation and self-assembles into a nanoplate with higher thermal stability. The supramolecular structure of FFf consists of intra- and intermolecular hydrogen bonds and π-π stackings. From our results, we have discovered that FFf forms a new type of self-assembling γ-turn conformation, clarifying the structural role of a d-amino acid residue in supramolecular formation.
由于具有潜在的构建新型功能材料的能力，基于苯丙氨酸的自组装肽引起了人们的兴趣。在这里，我们设计了四个非对映异构体，l-苯丙氨酸-l-苯丙氨酸-l-苯丙氨酸（FFF）、d-苯丙氨酸-l-苯丙氨酸-l-苯丙氨酸（fFF）、l-苯丙氨酸-d-苯丙氨酸-l-苯丙氨酸（FfF）和 l-苯丙氨酸-l-苯丙氨酸-d-苯丙氨酸（FFf），以分析 d-异构体对自组装的影响。通过 SEM、TG、VCD 和固态 NMR 测量，我们发现只有 FFf 形成 γ-转角构象，并自组装成具有更高热稳定性的纳米板。FFf 的超分子结构由分子内和分子间氢键以及 π-π 堆积组成。从我们的结果中，我们发现 FFf 形成了一种新的自组装 γ-转角构象，阐明了 d-氨基酸残基在超分子形成中的结构作用。
