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）：本申请的目的是请求配备 10 英寸电磁体/12 kW 电源的 Bruker BioSpin Corporation Elexsys E560 连续波电子顺磁共振 (EPR) 波谱仪，该波谱仪将在 X 波段（9- 10 GHz）和 Q 波段（34 GHz）微波频率，并包括用于 X 和 Q 波段的电子核双谐振（ENDOR、TRIPLE）配件。用于在液氦和氮气温度下运行的低温恒温器，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，该新仪器将取代老化的 EPR 光谱仪系统。用户组包括 PI（经验丰富的 EPR）。该仪器将支持 NIH 资助的四位用户的研究（5 R01 拨款）、NIH 资助的一位用户的待决研究。拟议的 EPR/ENDOR 项目包括以下内容：(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) 研究铁的新兴新生物学功能。 -生物素合酶、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的硫簇，与穆斯堡尔光谱相结合，(c) 的机制甲苯单加氧酶对芳香烃的生物转化，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) 确定二价金属在纤维形成机制中的作用淀粉样蛋白形成的过程，以及 (f) 新型有机金属复合物自由基介导的 DNA 链断裂和组蛋白修饰机制的表征。由于需要增强 EPR 和 ENDOR 频谱的分辨率，Q 频段的操作是合理的，并且 X 和 Q 频段的双操作对于成功限制频谱模拟分析的多频率方法至关重要。所要求的 EPR 光谱仪支持的项目涵盖了广泛公认的生物自由基反应性的研究，从酶中“编程”的必需自由基，到自由基和金属的有害影响，再到使用自由基反应性作为治疗工具。因此，预计 EPR 光谱仪将对生物医学产生持续的重大影响。