Acquisition of a modern continuous wave EPR spectrometer equipped with an ENDOR s

描述(由申请人提供)：本建议书申请资助购买一台新的现代连续波(CW)X波段(~9 GHz)电子顺磁共振(EPR)光谱仪，即配备E560D电子-核双共振(Endor)系统的Bruker Elexsys E500，以支持美国国立卫生研究院资助的亚利桑那大学的生化/生物医学研究。该光谱仪将集成到亚利桑那大学化学和生物化学系现有的EPR设备中，在那里它将取代现有的老化(约20年)的Bruker ESP300E CW EPR仪器。老旧的光谱仪出现了硬件问题，它的许多部件完全过时了，随时发生关键故障的概率很高。这样的失败将阻碍NIH资助的用户在研究中依赖EPR的项目的进展。用新的现代光谱仪取代旧光谱仪将确保用户不间断地接触电子顺磁共振，并将通过新仪器的显著(高达一个数量级)更高的灵敏度和通过提供对CW Endor实验的访问来丰富他们的研究能力。短期内，这台光谱仪将用于为这一提议做出贡献的用户正在进行的生化/生物医学研究项目。从长远来看，这台光谱仪将满足未来NIH资助的研究人员和亚利桑那大学EPR设备的其他用户在EPR实验中的需求。本建议中描述的具体受影响的生化/生物医学项目包括：(1)利用EPR和CW Endor研究亚硫酸盐氧化酶的钼催化中心，并模拟J.H.Enemark博士合成的钼(V)配合物。这项研究很重要，因为人类亚硫酸盐氧化酶的一些点突变会产生致命的后果；(2)F.A.Walker博士、K.M.Miranda博士和W.R.Montfort博士利用EPR了解一氧化氮、一氧化氮的结构和动态方面的化学变化；(3)F.A.Walker博士、K.M.Miranda博士和W.R.Montfort博士利用EPR来测试新开发的潜在抗癌药物的有效性；R.T.Dorr博士利用EPR来研究铜与蛋白质的结合与金属动态平衡和金属抗药性的关系。

DESCRIPTION (provided by applicant): This proposal requests funding for acquisition of a new, modern continuous wave (CW) X-band (~9 GHz) electron paramagnetic resonance (EPR) spectrometer, Bruker Elexsys E500 equipped with E560D electron-nuclear double resonance (ENDOR) system, to support the NIH-funded biochemical/biomedical research at the University of Arizona. This spectrometer will be integrated into the existing EPR Facility at the Department of Chemistry and Biochemistry of the University of Arizona, where it will replace the existing aging (~20 years old) Bruker ESP300E CW EPR instrument. The old spectrometer has developed hardware problems, many of its components are completely outdated, and there is a high probability of a critical failure at any time. Such a failure will impede the progress of the projects of the NIH-funded users relying on EPR in their research. The replacement of the old spectrometer by a new, modern one will ensure an uninterrupted access of the users to EPR and will enrich their research capabilities through a significantly (up to an order of magnitude) higher sensitivity of the new instrument and through providing access to CW ENDOR experiments. In short term, this spectrometer will be used in the ongoing biochemical/biomedical research projects of the users who contributed to this proposal. In the long term, this spectrometer will answer the need in EPR experiments of the future NIH-funded researchers and other users of the EPR Facility at the University of Arizona. The specific affected biochemical/biomedical projects described in this proposal include: (1) Using EPR and CW ENDOR to study the molybdenum catalytic center of sulfite-oxidizing enzymes and model synthetic Mo(V) complexes by Dr. J.H. Enemark. This research is important because some point mutations of human sulfite oxidase has fatal consequences; (2) Using EPR for understanding structural and dynamic aspects of chemistry of nitric oxide, NO, which has numerous biological functions important for human health by Drs. F.A. Walker, K.M. Miranda and W.R. Montfort; (3) Using EPR to test the efficiency of newly developed potential cancer drugs suppressing the function of ribonucleotide reductase by Dr. R.T.Dorr; (4) Using EPR to study Cu binding to proteins in relation to metal homeostasis and metal resistance by Dr. M. McEvoy.