中国科学院青岛生物能源与过程研究所姚礼山团队报道了用核磁共振波谱定量细胞内蛋白质静电相互作用。相关研究成果于2021年11月12日发表于国际顶尖学术期刊《美国化学会杂志》。

大多数蛋白质在细胞中执行其功能。细胞环境如何调节蛋白质相互作用是一个重要的问题。

该文中，研究人员使用细胞内核磁共振（NMR）光谱研究了蛋白质电荷之间的静电相互作用。在蛋白质GB3中总共引入了八个电荷对。与缓冲液中的电荷对静电相互作用相比，细胞中的五个电荷对没有明显变化，而三个电荷对的相互作用减弱了70%以上。进一步的研究表明，转移自由能是静电相互作用调制的原因。折叠态和未折叠态的转移自由能都有助于蛋白质静电的细胞环境效应，尽管后者通常比前者更大（更负）。

该工作强调了直接在细胞内研究蛋白质相互作用以及蛋白质功能的重要性。

附：英文原文

Title: Quantifying Protein Electrostatic Interactions in Cells by Nuclear Magnetic Resonance Spectroscopy

Author: Xiangfei Song, Mengting Wang, Xiaoxu Chen, Xueying Zhang, Ying Yang, Zhijun Liu, Lishan Yao

Issue&Volume: November 12, 2021

Abstract: Most proteins perform their functions in cells. How the cellular environment modulates protein interactions is an important question. In this work, electrostatic interactions between protein charges were studied using in-cell nuclear magnetic resonance (NMR) spectroscopy. A total of eight charge pairs were introduced in protein GB3. Compared to the charge pair electrostatic interactions in a buffer, five charge pairs in cells displayed no apparent changes whereas three pairs had the interactions weakened by more than 70%. Further investigation suggests that the transfer free energy is responsible for the electrostatic interaction modulation. Both the transfer free energy of the folded state and that of the unfolded state can contribute to the cellular environmental effect on protein electrostatics, although the latter is generally larger (more negative) than the former. Our work highlights the importance of direct in-cell studies of protein interactions and thus protein function.

DOI: 10.1021/jacs.1c10154

Source: https://pubs.acs.org/doi/10.1021/jacs.1c10154