Development of a 750 MHz NMR Spectrometer

摘要 要求提供70万美元的资金，用于购买17.6特斯拉的核磁共振磁铁，并用于设计和建造配套的核磁共振控制台。750 MHz。我们建议建造的NMR控制台将能够执行参与教师研究计划所需的各种NMR实验。这些实验包括：由Brian Reid的小组用于研究核酸溶液结构的同质二维实验如NOESY和ECOSY，由Rachel Klevit的小组用于研究蛋白质、蛋白质-蛋白质和蛋白质-核酸复合物的结构的异质多维实验如HMQC-NOESY，固态NMR技术如氘宽线NMR、旋转共振（R2）和RFDR，加里·德罗布尼的研究小组用来研究核酸和非常大的核酸-蛋白质复合物的结构和动力学，以及高分辨率氚NMR，迈克尔·海涅基的研究小组用来研究无机金属氢化物复合物的动力学，海因茨·弗洛斯的研究小组用来研究天然产物和代谢物的结构。 对于使用NMR作为探测分子结构的主要工具的Klevit、Drobny和Reid小组，对更高场的需求主要是由对更高灵敏度的需求驱动的。 贯穿所有三个程序的一个共同主题是对研究复合物中核酸和蛋白质结构的兴趣。然而，众所周知，蛋白质-核酸复合物是不溶性的，因此需要更高的灵敏度来研究溶液中非常低浓度的复合物。德罗布尼小组已使用固态核磁共振实验来测量标记核酸中的核间距离，从而使研究与蛋白质的非常大的复合物中的DNA和RNA结构成为可能，但许多重要的固态核磁共振实验，即多量子实验，灵敏度太低，无法实际用于生物聚合物的大型复合物。我们估计，灵敏度提高约2.8倍将大大扩展我们可以使用这种方法研究的分子大小的范围。此外，一些其他教师将找到一个750兆赫。光谱仪有用或至关重要的研究计划。这些学院包括：研究蛋白质折叠的大卫贝克需要高灵敏度的核磁共振仪器，因为折叠中间体非常难溶解。研究生物材料的Pat Stayton需要高灵敏度的NMR设备来研究13000分子量蛋白质链霉亲和素的溶液结构，链霉亲和素是生物传感器的重要组成部分，并且在溶液中四聚化。计划研究高分子量DNA的溶液动力学的J. Michael Schurr也需要高场NMR仪器。 华盛顿大学有资格承担高场核磁共振仪器的研制。自1985年以来，已经设计和建造了三台NMR光谱仪，包括：两台500 MHz。控制台（两者都能够执行高分辨率和固态NMR实验）和400 MHz。固态NMR光谱仪（主要用于高速魔角样品旋转实验）。此外，U.W.最近收到了巴特尔的太平洋西北实验室的合同，设计，原型，并建造一个900 - 1000兆赫。核磁共振为能源部资助的环境和分子科学实验室。本设计工作频率为900 - 1000 MHz。核磁共振控制台已经在进行中，可以很容易地适应750兆赫。console.最后，计划与共振研究公司合作，旨在应用矩阵匀场技术来产生用于多维NMR实验和显微成像的脉冲场梯度。在这项计划工作的第一阶段，我们将尝试使用矩阵技术在11.75特斯拉的磁铁中产生脉冲梯度。随后将应用于更高的场系统。

ABSTRACT Funding is requested in the amount of $700,000 toward the purchase of a 17.6 Tesla NMR magnet and toward the design and construction of an accompanying NMR console. The 750 MHz. NMR console that we propose to construct, will be capable of performing the wide variety of NMR experiments required by the research programs of the participating faculty. These experiments include: homonuclear two dimensional experiments like NOESY and ECOSY, used by Brian Reid's group to study nucleic acids solution structure, heteronuclear multi-dimensional experiments like HMQC-NOESY, used by Rachel Klevit's group to study the structure of proteins, protein-protein and protein-nucleic acids complexes, solid state NMR techniques like deuterium wide line NMR, Rotational Resonance (R2) and RFDR, used by Gary Drobny's group to study the structure and dynamics of nucleic acids and of very large nucleic acid-protein complexes, and high resolution tritium NMR, used by Michael Heinekey's group to study the kinetics of inorganic metal hydride complexes and by Heinz Floss' group to study the structure of natural products and metabolites. For the groups of Klevit, Drobny, and Reid, which use NMR as a primary tool for probing molecular structure, the need for higher field is driven mainly by a requirement for higher sensitivity. A common theme running through all three programs is the interest in studying the structure of nucleic acids and proteins in complexes. However, protein-nucleic acid complexes are notoriously insoluble, hence the need for higher sensitivity to study very low concentrations of complexes in solution. Solid state NMR experiments have been used by the Drobny group to measure internuclear distances in labeled nucleic acids, making possible the study of DNA and RNA structure in very large complexes with proteins, but a number of important solid state NMR experiments, i.e. multiple quantum experiments, are simply too low in s ensitivity to be practical for use in large complexes of biopolymers. We estimate that the factor of roughly 2.8 improvement in sensitivity will greatly expand the domain of molecular size that we can study using such methods. In addition, a number of other faculty will find a 750 MHz. spectrometer useful or crucial for their research programs. These faculty include: David Baker, who studies protein folding, needs high sensitivity NMR instrumentation because folding intermediates are very insoluble. Pat Stayton, who studies bio-materials, requires high sensitivity NMR equipment to study the solution structure of the 13000 molecular weight protein Streptavidin, which is an important component in biosensors, and which tetramerizes in solution. J. Michael Schurr, who plans to study the solution dynamics of high molecular weight DNA, also requires high field NMR instrumentation. The University of Washington is qualified to carry of the development of high field NMR instrumentation. Three NMR spectrometers have been designed and built since 1985 including: two 500 MHz. consoles (both capable of performing high resolution and solid state NMR experiments), and a 400 MHz. solid state NMR spectrometer (used primarily for high speed magic angle sample spinning experiments). In addition, the U.W. has recently received a contract from Battelle's Pacific Northwest Lab to design, prototype, and construct a 900-1000 MHz. NMR for the DOE-funded Environmental and Molecular Sciences Laboratory. The design work for the 900-1000 MHz. NMR console is already in progress, and can be easily adapted to a 750 MHz. console. Finally, a collaborative effort is planned with Resonance Research Inc., aimed at applying matrix shim technology to produce pulsed field gradients for multi-dimensional NMR experiments and micro-imaging. In the first phase of this planned effort, we will attempt to use matrix technology to produce pulsed gradients in an 11.75 Tesla magnet. Applications to higher field systems will follow.