ELECTRON PARAMAGNETIC RESONANCE SPECTROMETER

该提案寻求为多功能X-波段/Q-波段电子顺磁共振(EPR)光谱仪提供资金。主要使用者包括劳伦斯伯克利国家实验室物理生物科学部的朱迪思·克林曼教授、詹姆斯·麦卡斯克教授、肯尼斯·雷蒙德教授、肯尼斯·鲍尔教授、大卫·韦默教授、梅尔文·克莱恩博士和维塔尔·亚钱德拉博士。这组科学家的研究兴趣涉及金属酶化学、生物无机化学、电子转移、神经生物化学和光合作用。这项建议描述了EPR光谱如何在这些领域中的每一个领域中发挥重要作用，识别和表征化学和生化系统，以及帮助阐明蛋白质功能的机制和光诱导电子转移过程中的电子转移途径。例如，克林曼教授的研究涉及一系列含铜和含铁的酶的活性机制。电子顺磁共振波谱既可以用来表征酶的金属活性部位(S)，也可以用来鉴定正在研究的整个生化过程中的中间体。Sauer教授、Klein博士和Yachandra博士致力于光系统II的放氧复合体的研究，广泛使用EPR光谱来帮助表征参与H20到O2转化的物种。麦卡斯克教授的研究关注多核团簇中电子交换和电子转移之间的相关性，例如在电子转移蛋白质中发现的电子转移。电子顺磁共振可以用来鉴定电子转移光产物，以及帮助表征团簇本身的电子结构。Raymond教授的研究也在生物无机化学领域，EPR光谱是表征铁载体以及超分子组装中原子间相互作用的重要技术。最后，Wemmer教授对Prion蛋白质结构动力学的研究可以利用EPR光谱来确定蛋白质的结构，利用未配对自旋可以相互作用的长距离，补充了他的核磁共振技术提供的局部和短期结构信息。所有这些群体显然都需要常规使用EPR光谱仪，但加州大学伯克利分校没有这样的仪器。因此，这项提议寻求资金用于购买具有可变温度(1.8-400K)以及X波段(约9千兆赫)和Q波段(35千兆赫)能力的最先进的光谱仪。我们相信，研究所的这项投资不仅将极大地促进主要用户群体的研究，而且将极大地促进加州大学伯克利分校化学系的整体研究。

This proposal seeks funding for a versatile X-band/Q-band electron paramagnetic resonance (EPR) spectrometer. The group of major users consists of Professors Judith Klinman, James McCusker, Kenneth Raymond, Kenneth Sauer, David Wemmer, and Drs. Melvin Klein and Vittal Yachandra of the Physical Biosciences Division of the Lawrence Berkeley National Laboratory. The research interests of this group of scientists span metalloenzyme chemistry, bioinorganic chemistry, electron transfer, neurobiochemistry, and photosynthesis. This proposal describes how, in each of these areas, EPR spectroscopy can play a vital role in the identification and characterization of chemical and biochemical systems, as well as helping to elucidate mechanisms of protein function and electron transfer pathways in photo-induced electron transfer processes. For example, Professor Klinman's research is concerned with the mechanism of activity in a wide range of Cu- and Fe-containing enzymes. EPR spectroscopy can be utilized both to characterize the metal-based active site(s) of the enzyme as well as identify intermediates in the overall biochemical process being studied. Professor Sauer and Drs. Klein and Yachandra work on the oxygen-evolving complex of photosystem II, using EPR spectroscopy extensively to help characterize species involved in the conversion of H20 to O2. Professor McCusker's research concerns the correlation between electron exchange and electron transfer in polynuclear clusters such as those found in electron transfer proteins. EPR can be used to identify electron transfer photoproducts as well as help to characterize the electronic structures of the clusters themselves. Professor Raymond's research is also in the area of bioinorganic chemistry, where EPR spectroscopy is an important technique for the characterization of Fe siderophores, as well as interatomic interactions in supramolecular assemblies. Finally, Professor Wemmer's research on the structural dynamics of the prion protein can utilize EPR spectroscopy to determine the structure of the protein by taking advantage of the long distance over which unpaired spins can interact, complimenting the local and short-range structural information afforded by his NMR techniques. All of these groups have a clear need for routine access to an EPR spectrometer, yet the University of California at Berkeley does not have such an instrument. This proposal therefore seeks funding for the acquisition of a state-of-the-art spectrometer with variable-temperature (1.8 - 400 K) as well as both X-band (ca. 9 GHz) and Q-band (35 GHz) capabilities. We believe that this investment on the part of the Institute will greatly enhance not only the research of the major user group, but of the Department of Chemistry at UC Berkeley as a whole.