Development of MAS NMR RF Power and Spinning Speed Controllers and 1H-X Dipolar Recoupling Methods

该项目由化学部门的化学测量和成像项目资助，支持西弗吉尼亚大学的Terry Gullion教授开发磁共振方法（类似于磁共振成像中使用的方法）来确定固相蛋白质的结构。蛋白质是控制生物过程的关键成分。确定它们的结构可以更好地了解它们的生化功能。例如，蛋白质在金属纳米颗粒上的相互作用为靶向癌细胞提供了潜在的治疗方法。为了帮助交流这门科学，Gullion博士和他的团队正在开发并向公众展示化学，为小学生和中学生提供教育机会，并为本科生和研究生开发在线教程。本文主要研究了魔角自旋核磁共振（MAS NMR）硬件和技术的发展。第一个目标是开发长期核磁共振实验所需的高稳定性MAS核磁共振硬件。一种控制器正在设计中，以精确控制射频（rf）功率水平，以满足核磁共振实验的需要，核磁共振实验旨在通过偶极重偶联确定分子结构。在MAS核磁共振实验中，一种控制样品旋转速度的新方法也正在开发中。这使得需要射频脉冲序列的核磁共振实验能够与样品旋转同步应用。第二个目标是发展MAS - NMR 1H-Ag， 1H-Au， 1H-2H偶极重偶联实验，以确定化学吸附在金和银纳米颗粒上的肽的结构，并确定吸附肽与金属表面之间的相对取向。为了帮助刚刚开始使用固态核磁共振的本科生和研究生，一系列描述核磁共振硬件的教育教程正在制作并发布在网上。

This project, funded by the Chemical Measurement & Imaging Program of the Chemistry Division, supports Professor Terry Gullion of West Virginia University to develop magnetic resonance methods (analogous to those used in magnetic resonance imaging) to determine the structures of proteins in the solid phase. Proteins are key components in the control of biological processes. Determination of their structures can lead to better understanding of their biochemical functions. For example, interactions of proteins on metallic nanoparticles offer potential therapies for targeting cancer cells. To help communicate this science, Dr. Gullion and his group are developing and presenting chemistry to the public, providing educational opportunities for elementary and middle school students, and developing online tutorials for undergraduate and graduate students.This work focuses on the development of magic-angle spinning nuclear magnetic resonance (MAS NMR) hardware and techniques. The first goal is the development of high-stability MAS NMR hardware necessary for long-term NMR experiments. A controller is being designed to accurately control radio-frequency (rf) power levels as needed for NMR experiments designed to determine molecular structures by dipolar recoupling. A novel method to control the sample spinning speed during MAS NMR experiments is also being developed. This enables NMR experiments that require rf pulse trains to be applied synchronously with the sample rotation. A second goal is to develop MAS NMR 1H-Ag, 1H-Au, 1H-2H dipolar recoupling experiments to determine the structures of peptides chemisorbed on gold and silver nanoparticles and to determine the relative orientation between the adsorbed peptide and the metal surface. To help undergraduate and graduate students that are just beginning to work in solid-state NMR, a series of educational tutorials describing NMR hardware is being produced and posted online.