Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78464, Konstanz, Germany.
Angew Chem Int Ed Engl. 2024 Jul 1;63(27):e202401343. doi: 10.1002/anie.202401343. Epub 2024 Jun 4.
The analysis of pressure induced changes in the chemical shift of proteins allows statements on structural fluctuations proteins exhibit at ambient pressure. The inherent issue of separating general pressure effects from structural related effects on the pressure dependence of chemical shifts has so far been addressed by considering the characteristics of random coil peptides on increasing pressure. In this work, chemically and pressure denatured states of the cold shock protein B from Bacillus subtilis (BsCspB) have been assigned in 2D H-N HSQC NMR spectra and their dependence on increasing hydrostatic pressure has been evaluated. The pressure denatured polypeptide chain has been used to separate general from structural related effects on H and N chemical shifts of native BsCspB and the implications on the interpretation of pressure induced changes in the chemical shift regarding the structure of BsCspB are discussed. It has been found that the ensemble of unstructured conformations of BsCspB shows different responses to increasing pressure than random coil peptides do. Thus, the approach used for considering the general effects that arise when hydrostatic pressure increases changes the structural conclusions that are drawn from high pressure NMR spectroscopic experiments that rely on the analysis of chemical shifts.
压力诱导的蛋白质化学位移变化分析可用于研究蛋白质在环境压力下的结构波动。迄今为止，通过考虑随机卷曲肽在升压过程中的特性，解决了将一般压力效应与结构相关效应分离的固有问题。在这项工作中，枯草芽孢杆菌冷休克蛋白 B（BsCspB）的化学和压力变性状态在二维 H-N HSQC NMR 光谱中得到了分配，并评估了它们对静水压力增加的依赖性。用压力变性的多肽链来分离结构相关和非结构相关的 H 和 N 化学位移对天然 BsCspB 的影响，并讨论了它们对 BsCspB 结构的化学位移诱导变化的解释的影响。结果发现，BsCspB 的无规卷曲构象的集合对压力的响应与随机卷曲肽不同。因此，当静水压力增加时，用于考虑一般效应的方法改变了从依赖于化学位移分析的高压 NMR 光谱实验中得出的结构结论。
