Induced-fit expansion and contraction of a self-assembled nanocube finely responding to neutral and anionic guests

• Published in: Nature communications Vol. 9; no. 1; pp. 4530 - 6
• Main Authors: Zhan, Yi-Yang, Kojima, Tatsuo, Nakamura, Takashi, Takahashi, Toshihiro, Takahashi, Satoshi, Haketa, Yohei, Shoji, Yoshiaki, Maeda, Hiromitsu, Fukushima, Takanori, Hiraoka, Shuichi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 31.10.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 140/131; 639/638/541/965; 639/638/541/966; Binding sites; Chemistry; Conformation; Contraction; Humanities and Social Sciences; Hydrophobicity; multidisciplinary; Receptors; Science; Science (multidisciplinary); Self-assembly
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-06874-y

Induced-fit or conformational selection is of profound significance in biological regulation. Biological receptors alter their conformation to respond to the shape and electrostatic surfaces of guest molecules. Here we report a water-soluble artificial molecular host that can sensitively respond to the size, shape, and charged state of guest molecules. The molecular host, i.e. nanocube, is an assembled structure consisting of six gear-shaped amphiphiles (GSAs). This nanocube can expand or contract its size upon the encapsulation of neutral and anionic guest molecules with a volume ranging from 74 to 535 Å 3 by induced-fit. The responding property of this nanocube, reminiscent of a feature of biological molecules, arises from the fact that the GSAs in the nanocubes are connected to each other only through the hydrophobic effect and very weak intermolecular interactions such as van der Waals and cation-π interactions. Induced-fit binding, common in biological systems, is still relatively rare in artificial hosts. Here, the authors assemble a molecular cube from six gear-shaped faces, whose interdigitated design allows the cube to expand and contract in response to the size, shape, and charge of a guest molecule.