14.1 T magnet with +/-1280 G Field Regulation and Integrated MAS Cryogenic System

项目摘要 请求提供资金，用于购买一个14.1 T的磁铁，其孔径为89 mm，并具有集成磁场调节功能， 扫描主要领域<$1280 G，并购买集成魔角纺纱（MAS）低温系统。 磁体和低温将是用于DNP增强固态的600 MHz DNP NMR系统的重要组成部分 生物分子系统和材料的核磁共振光谱研究。该仪器将是第一个大型 美国境内的DNP NMR用户设施，并将作为非常成功的用户计划的一部分进行操作 国家强磁场实验室这一工具还将作为制定 用于增强灵敏度受限的生物分子系统（如膜）表征的RF探针 蛋白质、病毒衣壳组装体、淀粉样蛋白原纤维和与NIH资助相关的生物膜。此外，优化 将改进这些精密样品的样品制备技术。对可清扫的需求 宽孔14.1 T磁体，与常规ssNMR中使用的常规固定场磁体相反 光谱仪，源于基于回旋管的DNP NMR实验的特殊需要：窄带 设备，唯一的方式，目前这一代的回旋管可以容纳大量的自由基， DNP增强的生物分子研究所需要的是有能力改变拉莫尔 实验中涉及的电子的频率。要求低温系统能够实现最低的 魔角旋转和定向生物分子样品的温度，如DNP 增强与较低温度成线性比例。NHMFL的NMR用户设施已经支持一个 广泛的NIH资助的研究项目，在这个建议中，我们描述了16个NIH资助的项目， 处于开发和利用新的ssNMR工具用于结构生物学的最前沿， 拟议的文书。

PROJECT SUMMARY Funds are requested for the purchase of a 14.1 T magnet with an 89 mm bore and integrated field regulation to sweep the main field ¿1280 G and to purchase an integrated magic angle spinning (MAS) cryogenic system. The magnet and cryogenics will be vital parts of a 600 MHz DNP NMR system for DNP-enhanced solid state NMR spectroscopic studies of biomolecular systems and materials. This instrument will be part of the first large scale DNP NMR user facility within the U.S., and will be operated as part of the highly successful user program of the National High Magnetic Field Laboratory. This instrument will also serve as the focal point for developing RF probes to enhance the characterization of sensitivity-limited biomolecular systems such as membrane proteins, viral capsid assemblies, amyloid fibrils, and biofilms relevant to NIH funding. In addition, optimized techniques for sample preparation of these delicate samples will be refined. The need for a sweepable widebore 14.1 T magnet, as opposed to the conventional fixed-field magnet used in conventional ssNMR spectrometers, stems from a special need of the gyrotron-based DNP NMR experiment: being narrow-band devices, the sole way that the current generation of gyrotrons can accommodate the multitude of radicals that are demanded for DNP-enhanced biomolecular investigations is to have a capability to change the Larmor frequency of the electrons involved in the experiment. The cryogenic system is required to enable the lowest temperatures possible for both magic angle spinning and oriented biomolecular samples, as the DNP enhancement scales linearly with lower temperatures. The NMR user facilities of the NHMFL already support a broad range of NIH-funded research projects and in this proposal we describe sixteen NIH-funded projects that are at the forefront of developing and utilizing new ssNMR tools for structural biology and will directly benefit from the proposed instrument.