Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, Universitätsstrasse 31, D-93047 Regensburg, Germany.
J Am Chem Soc. 2011 Aug 31;133(34):13646-51. doi: 10.1021/ja2050698. Epub 2011 Aug 10.
The introduction of multidimensional NMR spectroscopy was a breakthrough in biological NMR methodology because it allowed the unequivocal correlation of different spin states of the system. The introduction of large pressure perturbations in the corresponding radio frequency (RF) pulse sequences adds an extra structural dimension into these experiments. We have developed a microprocessor-controlled pressure jump unit that is able to introduce fast, strong pressure changes at any point in the pulse sequences. Repetitive pressure changes of 80 MPa in the sample tube are thus feasible in less than 30 ms. Two general forms of these experiments are proposed here, the pressure perturbation transient state spectroscopy (PPTSS) and the pressure perturbation state correlation spectroscopy (PPSCS). PPTSS can be used to measure the rate constants and the activation energies and activation volumes for the transition between different conformational states including the folded and unfolded state of proteins, for polymerization-depolymerization processes, and for ligand binding at atomic resolution. PPSCS spectroscopy correlates the NMR parameters of different pressure-induced states of the system, thus allowing the measurement of properties of a given pressure induced state such as a folding intermediate in a different state, for example, the folded state. Selected examples for PPTSS and PPSCS spectroscopy are presented in this Article.
多维核磁共振波谱学的引入是生物核磁共振方法学的一个突破，因为它允许系统的不同自旋态的明确关联。在相应的射频（RF）脉冲序列中引入大的压力扰动为这些实验增加了一个额外的结构维度。我们已经开发了一种微处理器控制的压力跳跃单元，能够在脉冲序列中的任何点引入快速、强的压力变化。因此，在不到 30 毫秒的时间内，在样品管中重复 80 MPa 的压力变化是可行的。这里提出了这两种实验的一般形式，即压力扰动瞬态光谱学（PPTSS）和压力扰动状态相关光谱学（PPSCS）。PPTSS 可用于测量不同构象状态之间的过渡的速率常数和活化能以及活化体积，包括蛋白质的折叠和未折叠状态、聚合-解聚过程以及配体结合的原子分辨率。PPSCS 光谱学关联了系统的不同压力诱导状态的 NMR 参数，从而允许测量给定压力诱导状态的性质，例如，在不同状态下的折叠中间体。本文介绍了 PPTSS 和 PPSCS 光谱学的一些示例。
