ELECTRON PARAMAGNETIC RESONANCE SPECTROMETER

电子顺磁共振谱仪

• 批准号: 2286883
• 负责人: JOHN D LIPSCOMB
• 金额: $ 38.5万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-07-15 至 1998-07-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2286883
• 关键词: biomedical equipment purchase; biomedical equipment resource; cryoscience; electron spin resonance spectroscopy

We seek funding to purchase a Bruker ESP-300E X-band electron paramagnetic resonance (EPR) spectrometer to replace a 17 year old Varian E-109 instrument that can no longer be maintained. It is proposed to equip this instrument with an additional Q-band bridge and cavity, Q-and X-band Li He cryostats, and a dual mode cavity. The instrument is a key element in the work funded by 13 NIH grants from the "major" and "other" users groups. The major users group consists of Profs. John D. Lipscomb (P.I.), Lawrence Que, Jr., Marian T. Stankovich, and William B. Tolman. These individuals and many of the "other" users are members of the Center for Metals in Biocatalysis at the University of Minnesota. Many collaborations within this group have led to joint publications and student training. The EPR instrument plays a major role in the viability of this Center and the collaborations it engenders. Many different types of problems centered around metals in biology are represented in the research of major users group. These include investigations of both mononuclear and dinuclear iron cluster containing enzymes and relevant model systems; investigation of nitrogen metabolism in Cu and heme containing enzymes and model systems; and investigations of metallo- flavoprotein systems. All of these studies require stable temperatures near that of liquid helium. The Q band accessory is requested due to the need to investigate heme, nonheme, Mn, and Cu systems at more than one frequency in order to interpret the complex spectra that arise from coupling or small zero field splitting. Several of the enzymes and models under investigation exhibit novel EPR signals from integer spin systems. These signals have proven to be important tools in the investigation of key intermediates in the catalytic cycles of enzymes such as methane monooxygenase (MMO). Integer spin signal intensity is enhanced about 3-fold when observed using the requested dual mode cavity due to a difference in the selection rules versus those of the half integer spin systems that are the usual targets of EPR studies. Also, the background signals due to half integer spin systems are eliminated when the dual mode capacity is used. Integer spin signals often have intensity at zero magnetic field because the X-band quantum is comparable in energy to the zero field splitting. Use of the higher energy Q-band quantum will, in principle, allow more complete investigation of these integer spin systems. The current EPR system has been heavily used for its entire service lifetime and continues to be in high demand. It has been made available to the entire research community free of charge. The new instrument will allow us to continue this tradition and facilitate expansion into new areas such as ENDOR that cannot be readily implemented with the current instrument. A new laboratory designed specifically for EPR is part of the medical school basic sciences building currently under construction. This will allow the instrument to be placed adjacent to 5 other molecular structure core facilities as well as the relevant technical personnel.

我们寻求资金购买布鲁克ESP-300 E X波段电子 顺磁共振（EPR）光谱仪，以取代17岁的瓦里安 第109章不能再继续了 提出要 为该仪器配备一个额外的Q波段电桥和谐振腔，Q和 X波段Li He低温恒温器和双模腔。 乐器是一把钥匙 由13个NIH资助的“主要”和“其他”研究项目 用户组。 主要用户群由教授组成。 John D.利普斯科姆 （P.I.）， 小劳伦斯·奎，玛丽安·T Stankovich和William B.托尔曼 这些个人和许多“其他”用户都是该中心的成员 生物催化中的金属。 许多 该小组内部的合作导致了联合出版物， 学生培训。EPR工具在可行性方面发挥着重要作用 以及它所带来的合作。 许多不同类型 生物学中以金属为中心的问题在 主要用户群的研究。其中包括对两个 单核和双核含铁簇酶及相关 模型系统;铜和血红素的氮代谢研究 含有酶和模型系统;和金属- 黄素蛋白系统 所有这些研究都需要稳定的温度 接近液氦的温度。 Q波段附件的要求，由于 需要研究血红素，非血红素，锰，铜系统在一个以上的 频率，以解释复杂的频谱， 耦合或小的零场分裂。 几种酶和 研究中的模型表现出整数自旋的新颖EPR信号 系统. 这些信号已被证明是 酶催化循环中关键中间体的研究 如甲烷单加氧酶（MMO）。自旋信号强度为 当使用所要求的双模腔观察时， 由于选择规则与一半的选择规则不同， 整数自旋系统是EPR研究的常见目标。 还有， 由于半整数自旋系统的背景信号被消除 当使用双模式容量时。 自旋信号通常具有 在零磁场强度，因为X波段量子是可比的 零场分裂的能量 使用更高能量的Q波段 原则上，量子技术将允许对这些问题进行更全面的研究。 整数自旋系统 现行的生产者延伸责任制度已大量用于 它的整个使用寿命，并继续在高需求。 它有 免费提供给整个研究界。 的 新的文书将使我们能够继续这一传统， 扩展到新的领域，如ENDOR，无法立即实施 目前的文书。 一个新的实验室专门为 EPR是医学院基础科学建设的一部分，目前正在 建设 这将允许将仪器放置在邻近 5其他分子结构核心设施以及相关 技术人员。