2013.03.02《Nanomechanics of Cation–p Interactions in Aqueous Solution》

生物体系中一种重要的非共价相互作用是广泛存在的阳离子–π相互作用。该相互作用通常发生在富电子的芳香π体系（如苯丙氨酸 Phe、酪氨酸 Tyr 和色氨酸 Trp 的芳香侧链）与阳离子（如 Na+、K+，以及生理条件下带正电荷的赖氨酸和精氨酸侧链）之间。静电作用被认为是阳离子–π相互作用的重要贡献来源。有趣的是，在水溶液中，阳离子–π相互作用往往比传统离子盐桥表现出更强的稳定性，这主要归因于其较低的去溶剂化能垒。芳香π体系对不同阳离子的结合选择性在很大程度上受阳离子水化程度的影响。因此，阳离子–π相互作用对于理解蛋白质折叠、分子识别、生物黏附以及细胞间相互作用等生物物理过程具有重要意义。在发表于 Angewandte Chemie International Edition 的研究中，研究人员首次利用表面力仪（SFA）在分子尺度上对水溶液中的阳离子–π相互作用进行了定量测量。通过模拟蛋白质中的分子结构，研究人员定量测定了不同类型阳离子与芳香π体系之间在水溶液中的相互作用强度。该工作被认为是阳离子–π研究领域的重要里程碑，标志着这一相互作用从理论推测迈向了直接实验测量。相关结论可为功能材料设计、生物分子识别以及细胞间相互作用研究提供重要的理论指导。

第一作者：吕清叶；通讯作者：Dong Soo Hwang，曾宏波

An important non covalent interaction in biological systems is the widely present cation - π interaction. This interaction typically occurs between electron rich aromatic π systems (such as phenylalanine Phe, tyrosine Tyr, and tryptophan Trp aromatic side chains) and cations (such as Na+, K+, and physiologically charged lysine and arginine side chains). Electrostatic interactions are considered an important contributor to cation - π interactions. Interestingly, in aqueous solutions, cation - π interactions often exhibit stronger stability than traditional ion salt bridges, mainly due to their lower desolvation energy barrier. The binding selectivity of aromatic π systems to different cations is largely influenced by the degree of cation hydration. Therefore, cation - π interactions are of great significance for understanding biophysical processes such as protein folding, molecular recognition, biological adhesion, and intercellular interactions. In a study published in Angewandte Chemie International Edition, researchers used a surface force analyzer (SFA) for the first time to quantitatively measure cation - π interactions in aqueous solutions at the molecular scale. By simulating the molecular structure of proteins, researchers quantitatively measured the strength of interactions between different types of cations and aromatic π systems in aqueous solutions. This work is considered an important milestone in the field of cation - π research, marking the transition of this interaction from theoretical speculation to direct experimental measurement. The relevant conclusions can provide important theoretical guidance for the design of functional materials, recognition of biomolecules, and research on intercellular interactions.

Corresponding Author: Dong Soo Hwang，Hongbo Zeng

Nanomechanics of Cation   Interactions in Aqueous Solution(