Enhancing the sensitivity of biomolecular MAS NMR by new methods of Dynamic Nuclear Polarization

通过动态核极化新方法提高生物分子 MAS NMR 的灵敏度

• 批准号: 321027114
• 负责人: Dr. Guinevere Mathies
• 金额: --
• 依托单位: School of Chemistry
• 依托单位国家: 德国
• 项目类别: Independent Junior Research Groups
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/321027114?language=en
• 关键词: Enhancing; sensitivity; biomolecular; MAS; NMR

The research project comprises two parts, with magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy as the central theme. MAS makes it possible to acquire high-resolution NMR spectra of complex chemical systems in the solid state. Because there is no need for crystallization and no principal limitations exist on size and complexity, MAS NMR can provide high-resolution structural information on systems that are scarcely accessed with other spectroscopic methods, such as amorphous materials, amyloid fibrils, membrane proteins, and catalytic sites.The first part of the project focuses on the development of new microwave pulse sequences, which provide very efficient dynamic nuclear polarization (DNP). Dynamic nuclear polarization is an essential companion of MAS NMR spectroscopy as it strongly enhances its sensitivity. Two new DNP pulse sequences were recently introduced by our research group, one of which yielded particularly high sensitivity enhancement factors. Intriguingly, we are just beginning to understand why one DNP pulse sequence is better than the other. Hence, a research project, involving both DNP experiments and advanced numerical simulations of the DNP process, is proposed, which, if successful, will fix the basic design criteria for a DNP pulse sequence.In the second part, the use of MAS NMR spectroscopy to investigate the structure of amorphous calcium carbonate (ACC) is proposed. ACC is an essential precursor phase in the highly controlled, but poorly understood formation of skeletal parts by invertebrate organisms. ACC contains structural water, in an approximately one-on-one ratio with calcium carbonate, which is released upon crystallization. In spite of considerable effort, spectroscopic information on the atomic-level structure of ACC is scarce and, as a consequence, there exists no good structural model of ACC. This part of the proposal describes how 1H-13C MAS NMR correlation spectra of various forms of ACC, which are stabilized against crystallization by biopolymers, may provide specific information on the chemical environments of structural water in ACC.

该研究项目包括两个部分，以魔角旋转（MAS）核磁共振（NMR）光谱为中心主题。MAS使得在固态下获得复杂化学体系的高分辨率NMR谱成为可能。由于不需要结晶，也不存在尺寸和复杂性的主要限制，MAS NMR可以提供其他光谱方法难以获得的系统的高分辨率结构信息，例如无定形材料，淀粉样纤维，膜蛋白和催化位点。该项目的第一部分重点是开发新的微波脉冲序列，其提供非常有效的动态核极化（DNP）。动态核极化是MAS NMR光谱学的重要伴侣，因为它强烈增强了其灵敏度。我们的研究小组最近引入了两种新的DNP脉冲序列，其中一种产生了特别高的灵敏度增强因子。有趣的是，我们刚刚开始理解为什么一个DNP脉冲序列比另一个更好。因此，一个研究项目，包括DNP实验和先进的数值模拟的DNP过程中，提出，如果成功的话，将固定的基本设计准则的DNP脉冲sequence.In第二部分，使用MAS NMR光谱研究结构的无定形碳酸钙（ACC）的建议。ACC是无脊椎动物骨骼部分形成过程中一个重要的前体阶段，但对这一过程的了解甚少。ACC含有结构水，与碳酸钙的比例约为一对一，在结晶时释放。尽管付出了相当大的努力，ACC的原子级结构的光谱信息是稀缺的，因此，没有很好的结构模型ACC. This部分的建议介绍了如何1H-13 C MAS NMR相关光谱的各种形式的ACC，这是稳定对结晶的生物聚合物，可以提供具体的信息在ACC的化学环境中的结构水。