On the necessity of an integrative approach to understand protein structural dynamics

Abstract

Proteins are dynamic, fluctuating between multiple conformational states. Protein dynamics, spanning orders of magnitude in time and space, allow proteins to perform specific functions. Moreover, under certain conditions, proteins can morph into a different set of conformations. Thus, a complete understanding of protein structural dynamics can provide mechanistic insights into protein function. Here, we review the latest developments in methods used to determine protein ensemble structures and to characterize protein dynamics. Techniques including X-ray crystallography, cryogenic electron microscopy, and small angle scattering can provide structural information on specific conformational states or on the averaged shape of the protein, whereas techniques including nuclear magnetic resonance, fluorescence resonance energy transfer (FRET), and chemical cross-linking coupled with mass spectrometry provide information on the fluctuation of the distances between protein domains, residues, and atoms for the multiple conformational states of the protein. In particular, FRET measurements at the single-molecule level allow rapid resolution of protein conformational states, where information is otherwise obscured in bulk measurements. Taken together, the different techniques complement each other and their integrated use can offer a clear picture of protein structure and dynamics.

概要

蛋白质是动态的, 在多种结构状态间转化。蛋白 质的结构动态在时间和空间上跨越多个数量级, 允许蛋白质执行特定生物学功能。细胞条件和细 胞环境的变化会使蛋白质动态结构发生变化。因 此, 对蛋白质结构动态的全面表征可提供对蛋白 质功能的机制的深入了解。在这里, 我们综述了 用于测定蛋白质系综动态结构和表征蛋白质结 构动态变化的方法的最新发展。X 射线晶体学、 冷冻电镜和小角散射等技术可提供关于蛋白质 特定状态或平均的结构信息, 而核磁共振、荧光 共振能量转移(FRET)和化学交联质谱等技术 则提供了蛋白质结构域、蛋白质残基和原子之间 的处于不同结构状态时的距离波动信息。尤其要 指出的是, 单分子水平的FRET 测量能对蛋白质 构象状态进行快速区分, 而这样的信息会在其它 测量中被掩盖。总之, 不同的生物物理技术互为 补充, 只有通过它们的综合运用, 才能清晰可见 蛋白质结构和动态。