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Bruker ESP-300E X波段电子 顺磁共振（EPR）光谱仪替换17岁的Varian E-109无法维护的仪器。 提议 为该乐器配备额外的Q波段桥和空腔，Q- X波段Li He Ceryostats和双模式腔。 乐器是关键 由“主要”和“其他”资助的13个NIH赠款资助的工作中的要素 用户组。 主要用户组由教授组成。 John D. Lipscomb （P.I.），小劳伦斯·奎克（Lawrence Que），玛丽安·T·斯坦科维奇（Marian T. Stankovich）和威廉·B·托尔曼（William B. Tolman）。 这些人和许多“其他”用户是中心的成员 明尼苏达大学的生物催化金属。 许多 该小组内的合作导致了联合出版物和 学生培训。 EPR仪器在可行性中起主要作用 这个中心及其成立的合作。 许多不同的类型 在生物学中以金属为中心的问题中有代表 主要用户组的研究。这些包括对两者的调查 含有酶和相关的单核和双核铁簇 模型系统； 研究Cu和血红素中氮代谢的研究 包含酶和模型系统；并调查金属 黄素蛋白系统。 所有这些研究都需要稳定的温度 靠近液体氦气。 由于 需要在多个 频率以解释由 耦合或小零场分裂。 几种酶和 正在研究的模型展示了来自整数自旋的新型EPR信号 系统。 这些信号已被证明是重要工具 研究酶催化循环中的关键中间体 例如甲烷单加氧酶（MMO）。整数自旋信号强度为 使用请求的双模式腔观察到大约3倍 由于选择规则与一半的选择规则有所不同 整数旋转系统是EPR研究的通常目标。 还， 消除了由于半整数旋转系统而引起的背景信号 使用双模式容量时。 整数旋转信号通常具有 零磁场的强度，因为X波段量子是可比的 在零场分裂的能量中。 使用较高的能量Q波段 原则上，量子将允许对这些量子进行更多的完整调查 整数旋转系统。 当前的EPR系统已大量用于 它的整个服务寿命，并且需求仍然很高。 它有 免费提供给整个研究社区。 这 新工具将使我们能够继续这种传统并促进 扩展到无法容易实施的新领域，例如Endor 使用当前的仪器。 专为专为 EPR是目前医学院基础科学大楼的一部分 建造。 这将使乐器可以放置在 5其他分子结构核心设施以及相关的 技术人员。