Department of Structural and Molecular Biology, UCL, Gower St, London WC1E 6BT, UK.
Department of Structural and Molecular Biology, UCL, Gower St, London WC1E 6BT, UK.
J Magn Reson. 2021 May;326:106937. doi: 10.1016/j.jmr.2021.106937. Epub 2021 Feb 18.
NMR measurements of cross-correlated nuclear spin relaxation provide powerful probes of polypeptide dynamics and rotational diffusion, free from contributions due to chemical exchange or interactions with external spins. Here, we report on the development of a sensitivity-optimized pulse sequence for the analysis of the differential relaxation of transitions within isolated CH spin systems, in order to characterise rotational diffusion and side chain order through the product Sτ. We describe the application of optimal design theory to implement a real-time 'on-the-fly' adaptive sampling scheme that maximizes the accuracy of the measured parameters. The increase in sensitivity obtained using this approach enables quantitative measurements of rotational diffusion within folded states of translationally-arrested ribosome-nascent chain complexes of the FLN5 filamin domain, and can be used to place strong limits on interactions between the domain and the ribosome surface.
NMR 测量交叉相关核自旋弛豫为多肽动力学和旋转扩散提供了强大的探针，不受化学交换或与外部自旋相互作用的影响。在这里，我们报告了一种优化灵敏度的脉冲序列的开发，用于分析孤立 CH 自旋系统中跃迁的差异弛豫，以通过产物 Sτ 来表征旋转扩散和侧链有序性。我们描述了最优设计理论的应用，以实现实时“实时”自适应采样方案，最大限度地提高测量参数的准确性。使用这种方法获得的灵敏度提高使我们能够对翻译暂停核糖体新生链复合物的 FLN5 细丝蛋白域的折叠状态下的旋转扩散进行定量测量，并可用于对该结构域与核糖体表面之间的相互作用施加严格限制。
