A Resonator for Pulsed ODNP Spectroscopy to Study Surface Hydration Dynamics

项目摘要/摘要 提出的研究重点是开发一种用于液体状态Overhauser的交钥匙谐振器 动态核极化(ODNP)光谱研究水的特定位置平移动力学 位于生物大分子界面的分子，如膜蛋白。它将允许研究人员 在市面上可买到的最先进的X波段CW/PULSE中容易地进行ODNP实验 使用电子顺磁共振(EPR)光谱仪或使用台式ODNP光谱仪。 近年来，在核磁共振实验中，DNP已被证明是一种增强信号强度的可靠方法 在世界各地的实验室中，在使DNP用于固体和溶解方面取得了实质性进展- 状态核磁共振波谱。这一进展引起了人们对ODNP光谱学的新兴趣。尽管该方法 自20世纪60年代以来，它才被成功地应用于研究特定地点的翻译 位于膜蛋白等生物大分子界面的水的动力学。ODNP可以 绘制出膜蛋白和脂膜的局部和特定部位的水化动力学图景 并且可以提供有关蛋白质结构和动力学的关键信息。 ODNP光谱的主要挑战之一是微波诱导样品加热。在阶段中 在本项目中，我们成功地设计、制造并表征了一种新型的ODNP谐振器原型。这 SBIR第二阶段的应用将确保原型可以转化为客户产品。如图所示 通过样机，该谐振器的微波转换系数将比传统的微波转换系数高得多。 矩形或圆形EPR型腔。此外，低Q共振结构将允许脉冲ODNP 通过降低饱和所需的平均功率来进一步减少微波感应加热的实验 EPR过渡。 这项技术的成功开发将为研究人员提供使用仪器的途径 允许他们将ODNP光谱学纳入他们的研究程序中，而不需要麻烦地进行故障排除 自制设备。这将极大地推广该方法，并对许多由 美国国立卫生研究院。

Project Summary / Abstract The proposed research focuses on the development of a turn-key resonator for liquid-state Overhauser Dynamic Nuclear Polarization (ODNP) spectroscopy to study the site-specific translational dynamics of water molecules located at the interface of bio-macromolecules such as membrane proteins. It will allow researchers to readily perform ODNP experiments in either a state-of-the-art commercially available X-band cw/pulsed electron paramagnetic resonance (EPR) spectrometer or using a benchtop ODNP spectrometer. In recent years, DNP has proven to be a robust method to increase signal intensities in NMR experiments in laboratories around the world and substantial progress has been made in adapting DNP for solid- and solution- state NMR spectroscopy. This progress has sparked a new interest in ODNP spectroscopy. Although the method is known since the 1960s it has just recently been applied successfully to study the site-specific translational dynamics of water located at the interface of large bio-macromolecules such as membrane proteins. ODNP can map out the local and site-specific hydration dynamics landscape of membrane proteins and lipid membranes and can provide critical information about the protein structure and dynamics. One of the major challenges in ODNP spectroscopy is microwave induced sample heating. During Phase I of this project, we successfully designed, fabricated and characterized a novel prototype ODNP resonator. This SBIR Phase II application will assure that the prototype can be turned into a customer product. As demonstrated by the prototype, the resonator will have a much higher microwave conversion factor compared to conventional rectangular or circular EPR cavities. In addition, the low Q resonance structure will allow pulsed ODNP experiments to further minimize microwave induced heating by reducing the average power required to saturate the EPR transitions. The successful development of this technology will provide researchers access to instrumentation allowing them to incorporate ODNP spectroscopy in their research routine without the hassle of troubleshooting home-built equipment. This will greatly proliferate the method and is of large interest to many projects funded by the U.S. National Institutes of Health.