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(由申请人提供)：本申请的目标是申请一台Bruker BioSpin Corporation Elexsys E560连续波电子顺磁共振(EPR)光谱仪，配备10英寸电磁铁/12千瓦电源，可在X波段(9-10 GHz)和Q波段(34 GHz)微波频率下运行，并包括X和Q波段的电子-核双共振(Endor，三重)附件。还需要在液氦和氮气温度下运行的低温恒温器，以适应顺磁磁体的不同松弛特性，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，一位经验丰富的EPR光谱学家，以及其他三个主要用户和两个次要用户。该仪器将支持NIH资助的四个用户的研究(5 R01赠款)，一个用户的NIH资助的未决研究，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依赖的酶中缺电子自由基介导的催化的分子机制；(B)结合穆斯堡尔谱研究生物素合成酶、丙酮酸-甲酸裂解酶激活酶和铁氧还蛋白：硫氧还蛋白还原酶中铁硫簇的新生物功能；(C)通过结合蛋白质X射线结晶学检查单晶中的金属位置结构，研究甲苯单加氧酶生物转化芳香烃的机理；(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纤维形成机制中的作用，以及(F)用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。由于需要提高EPR和Endor谱的分辨率，Q波段的工作是合理的，而双X和Q波段的工作对于多频率方法的成功约束光谱模拟分析是必不可少的。所要求的EPR光谱仪支持的项目涵盖了对广泛公认的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。