美国斯坦福大学Boxer, Steven G.团队通过双向振动探针揭示了溶液和酶活性位点中不同的电场方向。相关研究成果于2022年5月5日发表于国际顶尖学术期刊《自然—化学》。

电场的催化能力取决于它相对于反应性化学物质的大小和方向。因此，理解和设计用于静电催化的新催化剂，需要在分子尺度上测量电场方向和大小的方法。

研究人员利用电子探针的两个振动方向，揭示了氘化碳的振动方向。将光谱学与分子动力学和电子结构分配方法相结合，研究人员发现，尽管极性不同，但溶剂在静电稳定大键偶极子方面的行为相似，而牺牲了小键偶极子的稳定性。相比之下，对于肝乙醇脱氢酶的活性部位乙醛抑制剂，电场方向明显偏离在溶剂中发现的方向，为溶剂的静电环境和预组织酶活性部位的静电环境之间的根本差异提供了直接证据。

附：英文原文

Title: A two-directional vibrational probe reveals different electric field orientations in solution and an enzyme active site

Author: Zheng, Chu, Mao, Yuezhi, Kozuch, Jacek, Atsango, Austin O., Ji, Zhe, Markland, Thomas E., Boxer, Steven G.

Issue&Volume: 2022-05-05

Abstract: The catalytic power of an electric field depends on its magnitude and orientation with respect to the reactive chemical species. Understanding and designing new catalysts for electrostatic catalysis thus requires methods to measure the electric field orientation and magnitude at the molecular scale. We demonstrate that electric field orientations can be extracted using a two-directional vibrational probe by exploiting the vibrational Stark effect of both the C=O and C–D stretches of a deuterated aldehyde. Combining spectroscopy with molecular dynamics and electronic structure partitioning methods, we demonstrate that, despite distinct polarities, solvents act similarly in their preference for electrostatically stabilizing large bond dipoles at the expense of destabilizing small ones. In contrast, we find that for an active-site aldehyde inhibitor of liver alcohol dehydrogenase, the electric field orientation deviates markedly from that found in solvents, which provides direct evidence for the fundamental difference between the electrostatic environment of solvents and that of a preorganized enzyme active site.

DOI: 10.1038/s41557-022-00937-w

Source: https://www.nature.com/articles/s41557-022-00937-w