[NMR paper] Volume and Compressibility Differences Between Protein Conformations Revealed by High-Pressure NMR.

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Volume and Compressibility Differences Between Protein Conformations Revealed by High-Pressure NMR.

Related Articles Volume and Compressibility Differences Between Protein Conformations Revealed by High-Pressure NMR.

Biophys J. 2021 Jan 29;:

Authors: Xu X, Gagné D, Aramini JM, Gardner KH

Abstract
Proteins often interconvert between different conformations in ways critical to their function. While 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 beta-strand register as it switches between two stably-folded conformations. Using high pressure biomolecular NMR approaches, we obtained the first quantitative data testing two key hypotheses of this process: the slipped conformation is both smaller and less compressible than the wildtype 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.


PMID: 33524371 [PubMed - as supplied by publisher]



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