Electron Paramagnetic Resonance Spectrometer

电子顺磁共振波谱仪

• 批准号: 6582101
• 负责人: KURT WARNCKE
• 金额: $ 26.14万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6582101
• 关键词: biomedical equipment purchase; electron nuclear double resonance spectroscopy; electron spin resonance spectroscopy; microwave radiation

DESCRIPTION (provided by applicant): The objective of this application is to request a Bruker BioSpin Corporation Elexsys E560 continuous-wave electron paramagnetic resonance (EPR) spectrometer with 10" electromagnet/12 kW power supply that will operate at X-band (9-10 GHz) and Q-band (34 GHz) microwave frequencies, and include the electron-nuclear double resonance (ENDOR, TRIPLE) accessories for X- and Q-band. Also requested are cryostats for operation at liquid helium and nitrogen temperature, to adjust to the different relaxation properties of the paramagnets, and a goniometer for single crystal studies. The new instrument would replace an aging EPR spectrometer system. The user group includes the PI, an experienced EPR spectroscopist, and three other Major Users and two Minor Users. The instrument will support the NIH-funded research of four users (5 R01 grants), the pending NIH-funded research of one user, and the preliminary studies of another. The proposed EPR/ENDOR projects include the following: (a) determination of the molecular mechanism of electrondeficient radical-mediated catalysis in coenzyme B12-dependent enzymes, (b) investigation of the emergent novel biological functions of iron-sulfur clusters in biotin synthase, pyruvate-formate lyase activating enzyme, and ferredoxin:thioredoxin reductase, in combination with Mossbauer spectroscopy, (c) the mechanism of biotransformation of aromatic hydrocarbons by toluene monooxygenases, by examining metal site structure in single crystals in combination with protein X-ray crystallography, (d) the structure and function of flavoenzymes, (e) determination of the role of divalent metals in the mechanism of fibrillogenesis in amyloid formation, and (f) characterization of the mechanism of radical-mediated DNA strand scission and histone modification by novel organometallic complexes. Operation at Q-band is justified by the need for enhanced resolution of both EPR and ENDOR spectra, and the dual X- and Q-band operation is essential for success of multi-frequency approaches to constrain spectral simulation analyses. The projects supported by the requested EPR spectrometer cover investigations of the wide range of recognized biological radical reactivity, from "programmed" essential radicals in enzymes, to deleterious effects of free radicals and metals, to the use of radical reactivity as a therapeutic tool. A sustained high impact of the EPR spectrometer on biomedicine is therefore anticipated.

描述（申请人提供）：本申请的目的是申请一台Bruker BioSpin Corporation Elexsys E560连续波电子顺磁共振（EPR）光谱仪，配有10”电磁铁/12 kW电源，可在X波段工作（9-10 GHz）和Q波段（34 GHz）微波频率，并包括用于X和Q波段的电子-核双共振（ENDOR，TRIPLE）附件。还需要在液氦和液氮温度下操作的低温恒温器，以适应顺磁体的不同弛豫特性，以及用于单晶研究的测角仪。新仪器将取代老化的EPR光谱仪系统。用户组包括PI、一名经验丰富的EPR光谱师以及其他三名主要用户和两名次要用户。该仪器将支持四个用户的NIH资助的研究（5 R 01赠款），一个用户的NIH资助的研究，以及另一个用户的初步研究。拟议的EPR/ENDOR项目包括：（a）确定辅酶B12依赖性酶中缺电子自由基介导的催化作用的分子机制，（B）研究生物素合酶、谷氨酸-甲酸裂解酶激活酶和铁氧还蛋白中铁硫簇的新生物学功能：硫氧还蛋白还原酶，结合穆斯堡尔谱学，（c）甲苯单加氧酶对芳烃的生物转化机理，通过结合蛋白质X射线晶体学检查单晶中的金属位点结构，（d）黄素酶的结构和功能，（e）确定二价金属在淀粉样蛋白形成中的纤维形成机制中的作用，和（f）通过新型有机金属络合物表征自由基介导的DNA链断裂和组蛋白修饰的机制。在Q波段的操作是合理的EPR和ENDOR光谱的分辨率增强的需要，和双X和Q波段操作是必不可少的成功的多频方法来约束频谱模拟分析。所要求的EPR分光计所支持的项目包括对广泛的公认生物自由基反应性的调查，从酶中的“程序化”基本自由基到自由基和金属的有害影响，再到将自由基反应性用作治疗工具。因此，EPR光谱仪对生物医学的持续高影响是可以预期的。