Becker Bridget A, Morris Kevin F, Larive Cynthia K
Department of Chemistry, University of California-Riverside, 328 Physical Sciences Building 1, Riverside, CA 92521-0403, USA.
J Magn Reson. 2006 Aug;181(2):327-30. doi: 10.1016/j.jmr.2006.04.010. Epub 2006 May 15.
In NMR diffusion experiments to study ligand-protein binding equilibria, the spectral background due to broad protein resonances can contribute significantly to the measured ligand signal intensity resulting in erroneous binding affinities. One method to suppress the protein spectral background involves coupling a CPMG pulse train before or after the BPPSTE pulse sequence to allow for differential T(2) relaxation of the broad protein resonances. Here, we present an improved method, the Gradient Phase Encoded Spin-lock (GraPES) experiment that integrates the relaxation filter into the diffusion period. Compared with sequential CPMG-BPPSTE pulse sequences, GraPES offers effective suppression of the protein background with improved signal-to-noise ratios and shorter experiment times.
在用于研究配体 - 蛋白质结合平衡的核磁共振扩散实验中，由于蛋白质宽共振峰导致的光谱背景会对所测量的配体信号强度产生显著影响，从而导致错误的结合亲和力。一种抑制蛋白质光谱背景的方法是在BPPSTE脉冲序列之前或之后耦合一个CPMG脉冲串，以使宽蛋白质共振峰实现不同的T(2)弛豫。在此，我们提出一种改进方法——梯度相位编码自旋锁定（GraPES）实验，该实验将弛豫滤波器集成到扩散期。与连续的CPMG - BPPSTE脉冲序列相比，GraPES能有效抑制蛋白质背景，同时提高信噪比并缩短实验时间。
