Time Domain EPR Spectrometer

描述(由申请人提供)： 需要资金以完成在范德比尔特大学购买Bruker EleXsys 580 FT-EPR系统。这种设备目前在校园或附近的任何机构都不可用，将由六个不同的现有研究小组用于对广泛的氮氧化物自旋标记蛋白质进行时间域EPR测量，这些蛋白质已经在使用传统的CW-EPR方法和现场定向自旋标记进行研究。在仪器和方法学方面的最新进展将时间域EPR定位为表征自旋标记蛋白质的结构和动力学的重要且在许多情况下是对CW-EPR的必要补充。在构成这一应用的核心用户群体的由美国国立卫生研究院资助的八个项目中，所要求的设备将用于：1)用鹿测量蛋白质中的“长”(&gt；20-25埃)探针间距离和/或双量子相干；2)测量在有或没有顺磁松驰剂的情况下自旋标记侧链的T1e，作为侧链可及性的直接指标；以及3)测量正在用包括饱和转移EPR在内的非线性方法研究的自旋标记蛋白质的T1e。在正在进行的八个项目中的每一个项目中，所要求的仪器都将产生立竿见影的实质性影响，提供独特的新测量能力，全面表征具有明显生物医学重要性的各种可溶性和膜结合蛋白的结构和动力学。范德比尔特和周围地区的其他研究人员也将获得所要求的仪器，因为他们正在开发涉及自旋标记的新项目。设备的公平使用将由内部监督委员会确保，日常操作将由经验丰富的EPR光谱仪处理。

DESCRIPTION (provided by applicant): Funds are requested to complete the purchase of a Bruker EleXsys 580 FT-EPR system at Vanderbilt University. This equipment, which is not currently available on campus or at any nearby institution, will be utilized by six different established research groups to make time-domain EPR measurements on a wide range of nitroxide spin-labeled proteins that are already being studied using conventional cw-EPR approaches and site-directed spin-labeling. Recent advances in instrumentation and methodology have positioned timedomain EPR as an important and in many cases an essential complement to cw-EPR for characterizing the structures and dynamics of spin-labeled proteins. In the eight NIH funded projects that constitute the core user group of this application, the requested equipment will be utilized to: 1) measure "long" (> 20 - 25 angstroms) inter-probe distances in proteins by DEER and/or double quantum coherence; 2) measure T1e's of spin-labeled side chains in the presence and absence of paramagnetic relaxation agents as a direct index of side-chain accessibility; and 3) measure T1e's for spin-labeled proteins that are being studied by non-linear methods including saturation transfer EPR. In each of the eight ongoing projects, the requested instrumentation will have an immediate and substantial impact by providing unique new measurement capabilities for full characterization of the structures and dynamics of wide range of soluble and membrane bound proteins that are of clear biomedical importance, The requested instrumentation will also be made available to other investigators at Vanderbilt and in the surrounding area as they develop new projects that involve spinlabeling. Equitable utilization of the equipment will be assured by an internal oversight committee and day to- day operation will be handled by an experienced EPR spectroscopist.