Q-band Upgrade to an X-band Pulsed EPR spectrometer

总结。 工作在34 GHz的连续波脉冲电子顺磁谱仪 (Q波段)是应哈佛医学院麻省理工学院化学研究人员的要求 化学与布兰迪斯生物化学。该仪器的功能包括脉冲Endor和 埃尔多。Q波段仪器的主要动机是大大提高了灵敏度和 与我们目前的X波段(9 GHz)光谱仪相比，我们的分辨率为34 GHz。这 提高敏感度和分辨率将使我们能够解决目前存在的许多问题 都超出了我们的科学能力范围。该仪器将补充高端X射线结晶学， 核磁共振(核磁共振)和低温电子显微镜(CryoEM)能力 波士顿地区实现多学科结构生物学和机械生物化学 对具有重大生物学和医学重要性的问题进行调查。研究项目 来自六个主要用户组(Griffin、Nocera、Nolan、Pandelia、Raines和Suess)以及来自 另外三个小团体(Betley Keissling和Wagner)也包括在提案中。 该仪器将推动以下与健康有关的研究：1)Endor和Essem研究 自由基SAM酶中的活性中间体，参与人体免疫的金属酶，以及 模拟固氮酶FeMo辅因子的多核铁络合物；2)脉冲EPR/DNP方法 旨在开发在高场下动态极化蛋白质的方法和鹿的研究 膜和可溶性蛋白质、胶原蛋白和多糖的二级结构；我们 预计以膜蛋白为靶点的进一步项目在神经学等领域具有重要意义 疾病和麻醉；以及在传染病中重要的病毒和细菌蛋白将出现 在光谱仪的生命周期内。

Summary. A continuous wave and pulsed electron paramagnetic (EPR) spectrometer operating at 34 GHz (Q-band) is requested by investigators at MIT Chemistry, Harvard Medical School, Harvard Chemistry and Brandeis Biochemistry. The instrument’s capabilities include pulsed ENDOR and ELDOR. The primary motivation for the Q-band instrument is the much improved sensitivity and resolution available at 34 GHz as compared to our current X-band (9 GHz) spectrometer. This improved sensitivity and resolution will permit us to address many problems which at the moment are beyond our scientific reach. The instrument will complement high-end X-ray crystallography, nuclear magnetic resonance (NMR), and cryoelectron microscope (cryoEM) capabilities in the Boston area to enable multidisciplinary structural biology and mechanistic biochemistry investigations of questions that are of great biological and medical importance. Research projects from six major user groups (Griffin, Nocera, Nolan, Pandelia, Raines, and Suess) and those from another three minor groups (Betley Keissling, and Wagner) are included in the proposal. The instrument will advance the following health-related research: 1) ENDOR and ESSEM studies of reactive intermediates in radical SAM enzymes, metalloenzymes involved in human immunity, and polynuclear Fe complexes that mimic the nitrogenase FeMo-cofactor; 2) pulsed EPR/DNP methods aimed at developing methods to dynamically polarize proteins at high fields and 3) DEER studies of membrane and soluble proteins, collagen, and polysaccharide secondary structure;. We anticipate that further projects targeting membrane proteins important for example in neurological disease and anesthesia; and viral and bacterial proteins important in infectious disease will appear during the lifetime of the spectrometer.