Sun Linhao, Li Peiying, Seki Takakazu, Tsuchiya Shohei, Yatsu Kazuki, Narimatsu Takuma, Sarikaya Mehmet, Hayamizu Yuhei
WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
Department of Materials Science and Engineering, Tokyo Institute of Technology, Tokyo 152-8550, Japan.
Langmuir. 2021 Jul 27;37(29):8696-8704. doi: 10.1021/acs.langmuir.1c00792. Epub 2021 Jul 18.
Chiral recognition of peptides on solid surfaces has been studied for a better understanding of their assembly mechanism toward its applications in stereochemistry and enantioselective catalysis. However, moving from small peptides such as dipeptides, understanding the chiral recognition of larger biomolecules such as oligopeptides or peptides with a larger sequence is challenging. Furthermore, their intrinsic mechanism for chiral recognition in liquid conditions was poorly investigated experimentally. Here, we used in/ex situ atomic force microscopy (AFM) to investigate the chiral recognition of self-assembled structures of l/d-type peptides on molybdenum disulfide (MoS). We chose single-layer MoS with a triangular shape as a substrate for the self-assembly of peptides. The facet edges of MoS were utilized as a landmark to identify the crystallographic orientation of their ordered structures. We found both peptide enantiomers formed nanowires on MoS with a mirror symmetry according to the facet edges of MoS. From in situ AFM measurements, we found a dimension of a unit cell in the self-assembled structure and proposed a model of lattice matching between peptides and MoS lattice. The lattice matching for chiral recognition was further investigated by changing peptide sequences and surface lattice from MoS to graphite. This work further deepened the understanding of biomolecular chiral recognition and will lead us to rationally design specific morphologies and conformations of chiral self-assembled structures of peptides with expected functions in the future.
为了更好地理解肽在立体化学和对映选择性催化中的组装机制，人们对固体表面肽的手性识别进行了研究。然而，从小肽（如二肽）过渡到理解较大生物分子（如寡肽或具有更大序列的肽）的手性识别具有挑战性。此外，它们在液体条件下手性识别的内在机制在实验上研究较少。在此，我们使用原位/非原位原子力显微镜（AFM）研究了l/d型肽在二硫化钼（MoS）上自组装结构的手性识别。我们选择三角形的单层MoS作为肽自组装的底物。利用MoS的晶面边缘作为地标来识别其有序结构的晶体学取向。我们发现两种肽对映体都在MoS上根据MoS的晶面边缘形成了具有镜像对称的纳米线。通过原位AFM测量，我们发现了自组装结构中晶胞的尺寸，并提出了肽与MoS晶格之间的晶格匹配模型。通过改变肽序列和从MoS到石墨的表面晶格，进一步研究了用于手性识别的晶格匹配。这项工作进一步加深了对生物分子手性识别的理解，并将引领我们在未来合理设计具有预期功能的肽手性自组装结构的特定形态和构象。
