Volume and compressibility differences between protein conformations revealed by high-pressure NMR
Volume and compressibility differences between protein conformations revealed by high-pressure NMR
复制标题
高压核磁共振揭示蛋白质构象之间的体积和可压缩性差异
DOI：
10.1016/j.bpj.2020.12.034
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发表时间：
2021
影响因子：
3.4
通讯作者：
Gardner, Kevin H.
中科院分区：
文献类型：
--
作者：
Xu, Xingjian;Gagné, Donald;Aramini, James M.;Gardner, Kevin H.
蛋白质经常以对其功能至关重要的方式在不同的构象之间相互转换。虽然在生物物理研究中操纵这样的平衡通常是具有挑战性的，但施加压力是实现这种控制的潜在途径，有利于低体积状态的种群。在这里，我们使用这一特征来研究ARNT PAS-B Y456T的相互转换，当它在两个稳定折叠的构象之间切换时，它在β-链寄存器中经历了一个戏剧性的+3滑移。利用高压生物分子核磁共振方法，我们获得了第一个定量数据，据我们所知，测试了这一过程的两个关键假设：滑移构象比野生型等效构象更小，可压缩性更低，相互转化通过主要展开的中间状态进行。在稳态压力和时间分辨压力跳跃模式下收集的数据，包括观察到的两种构象种群的压力依赖性变化和构象之间相互转换速率的增加，都支持这两种假设。我们的工作举例说明了这些可以普遍应用于蛋白质构象开关的方法如何能够提供通过其他技术不易获得的独特信息。
Proteins often interconvert between different conformations in ways critical to their function. Although manipulating such equilibria for biophysical study is often challenging, the application of pressure is a potential route to achieve such control by favoring the population of lower volume states. Here, we use this feature to study the interconversion of ARNT PAS-B Y456T, which undergoes a dramatic +3 slip in theβ-strand register as it switches between two stably folded conformations. Using high-pressure biomolecular NMR approaches, we obtained the first, to our knowledge, quantitative data testing two key hypotheses of this process: the slipped conformation is both smaller and less compressible than the wild-type equivalent, and the interconversion proceeds through a chiefly unfolded intermediate state. Data collected in steady-state pressure and time-resolved pressure-jump modes, including observed pressure-dependent changes in the populations of the two conformers and increased rate of interconversion between conformers, support both hypotheses. Our work exemplifies how these approaches, which can be generally applied to protein conformational switches, can provide unique information that is not easily accessible through other techniques.