中科院上海有机所Yanchuan Zhao课题组的最新研究报告了生物启发的杯[4]陷阱分子，可以作为具有双重选择机制的主体。 2021年2月19日出版的《美国化学会杂志》发表了这项成果。

据介绍，在时间和空间上进化的识别事件的调节对生命有机体是至关重要的。在进化过程中，生物体发展出独特的正交机制来实现选择性识别，从而避免了相互干扰。尽管将多种选择机制合并到单一人工主体中可能会产生具有无与伦比选择性的适应性更强的识别系统，但成功实施这种策略的情况很少。

受两种众所周知的生物离子结合剂（缬霉素和K通道）的有趣结构和识别特性的启发，研究团队在此报告了一系列配备双重客体选择机制的主体分子。这些主体同时具有一个预先组织的结合腔和一个受限的离子转运通道，这对K⁺/Na⁺的选择性和对多种离子对的识别能力至关重要，如K⁺/Rb⁺、K⁺/Ba²⁺和Rb⁺/Cs⁺。

机理研究证实，主体分子的门户能够根据阳离子的大小区分阳离子，从而实现不同的离子吸收率。承载连续结合位点的受限隧道促进了离子在被包含到埋藏腔中的完全脱溶，模拟了离子通道内的离子迁移。

他们的结果证明了在平衡和非平衡状态下操纵客体识别的能力，使得主体通过不同的机制有效地区分不同的客体。合并正交选择机制的策略为创建更多的耐用的主体开辟了一条新途径，这些主体可以在同时发生许多识别事件的复杂生物环境中运行。

附：英文原文

Title: Calix[4]trap: A Bioinspired Host Equipped with Dual Selection Mechanisms

Author: Zhenchuang Xu, Nie Fang, Yanchuan Zhao

Issue&Volume: February 19, 2021

Abstract: Regulation of recognition events evolving in time and space is vital for living organisms. During evolution, organisms have developed distinct and orthogonal mechanisms to achieve selective recognition, avoiding mutual interference. Although the merging of multiple selection mechanisms into a single artificial host may lead to a more adaptable recognition system with unparalleled selectivity, successful implementation of this strategy is rare. Inspired by the intriguing structures and recognition properties of two well-known biological ion binders—valinomycin and K+ channels—we herein report a series of hosts equipped with dual guest selection mechanisms. These hosts simultaneously possess a preorganized binding cavity and a confined ion translocation tunnel, which are crucial to the record-setting K+/Na+ selectivity and versatile capabilities to discriminate against a wide range of ion pairs, such as K+/Rb+, K+/Ba2+, and Rb+/Cs+. Mechanistic studies verify that the host’s portal is capable of discriminating cations by their size, enabling varied ion uptake rates. The confined tunnel bearing consecutive binding sites promotes complete desolvation of ions during their inclusion into the buried cavity, mimicking the ion translocation within ion channels. Our results demonstrate that the capability to manipulate guest recognition both in equilibrium and out-of-equilibrium states allows the host to effectively discriminate diverse guests via distinct mechanisms. The strategy to merge orthogonal selection mechanisms paves a new avenue to creating more robust hosts that may function in complex biological environments where many recognition events occur concurrently.

DOI: 10.1021/jacs.0c12223

Source: https://pubs.acs.org/doi/10.1021/jacs.0c12223