Characterization of dynamic processes in proteins by combining solid- and solutionstate NMR spectroscopy

应用研究项目的目标是结合溶液和MAS固态NMR光谱对蛋白质中的动态过程进行综合分析。两个申请小组的综合专业知识对拟议项目至关重要。蛋白质动力学是理解生物功能的关键要素。核磁共振弛豫实验可以表征这些动态过程。溶液中的弛豫由分子的整体翻滚（10-9 s）控制。只有快速运动过程（10-12-10-9秒），因此可以探测到使用溶液状态弛豫实验。在时间尺度10-9-10-7 s上的运动很难或不可能通过溶液状态弛豫测量来检测。使用残余偶极耦合的替代方法仍在讨论中。在这个建议中，我们建议结合联合收割机解决方案和MAS固态NMR数据来探测这些动态过程。我们试图确定，如果内部运动的变化后，从解决方案过渡到固体。虽然存在大量的证据表明动态行为是相似的，但另一方面，光谱背景是非常不同的：固态NMR光谱对宽范围的相关时间敏感，而溶液态NMR实验对更快的运动形式具有选择性。这开辟了有吸引力的可能性，详细和自足的内部蛋白质动力学的表征。拟议的工作将弥合现有的“时标差距”，并扩大了核磁共振动力学研究的边界。在拟议的研究中，固态实验将由Bernd Reif（BR）小组进行，而溶液工作则由Nikolai Skrynnikov（NS）小组负责。数据分析将共同进行。

The goal of the applied research project is an integrated analysis of dynamic processes in proteins combining solution and MAS solid-state NMR spectroscopy. The combined expertise of the two applying groups is essential for the proposed project. Protein dynamics is a key element for understanding of biological function. Nuclear magnetic resonance relaxation experiments allow the characterization of these dynamic processes. Relaxation in solution is controlled by the overall tumbling of the molecule (10-9 s). Only fast motional processes (10-12-10-9 s) can be therefore probed using solution-state relaxation experiments. Motions on the time scale 10-9-10-7 s are difficult or impossible to detect by solution-state relaxation measurements. Alternative approaches using residual dipolar couplings remain under discussion. In this proposal, we suggest to combine solution- and MAS solid-state NMR data to probe these dynamic processes. We seek to determine if internal motions are changed upon transition from solution to solids. While substantial evidences exist that the dynamic behavior is similar, the spectroscopic context, on the other hand, is very different: solid-state NMR spectroscopy is sensitive to a broad range of correlation times, while solution-state NMR experiments are selective with respect to faster forms of motion. This opens up attractive possibilities for a detailed and selfcontained characterization of internal protein dynamics. The proposed work will bridge the existing ‘time-scale gap’ and extend the boundaries of dynamics studies by NMR. In the proposed study, solid-state experiments will be conducted by the group of Bernd Reif (BR), while solution work is the responsibility of Nikolai Skrynnikov’s (NS) group. The data analysis will be carried out jointly.