High Field DNP and EPR in Biological Systems

项目描述（申请人提供）：拟开展高频动态核极化(DNP)/核磁共振、电子顺磁共振（EPR）和电子核双共振（ENDOR）研究。我们计划连续波和脉冲DNP实验，主要是时域EPR和ENDOR光谱。该研究将开发新的磁共振技术和方法，并解决一些有趣的生化系统中的结构问题。DNP: DNP实验可分为四(4)个努力领域。(1) CW MAS-DNP重点完成460 GHz/700 MHz DNP/NMR谱仪的设备设计与建设，DNP在膜和淀粉样蛋白结构生物学、可溶性蛋白GB1和17O MQMAS实验中的应用。(2)进一步发展T-Jump DNP实验，增强液体光谱中的核磁共振信号。(3)合成双极性极化剂，提高DNP的效率。(4)计划进行脉冲DNP实验，以提高电子-核极化转移效率。EPR/ENDOR：我们计划通过EPR和ENDOR解决5个领域的问题。(1)我们建议开发一种简单的方法来计算含有自由基的蛋白质的自旋计数(2)我们计划开发一个冷冻淬火装置，并研究RnR化学中短时间自由基中间体的形成动力学。(3)我们将重新研究无半乳糖氧化酶的高场EPR和ENDOR光谱，作为理解E441Q RnR和吉西他滨“3分钟”中间体中观察到的相同光谱的途径。(4)我们计划用TOAC标记来确定淀粉样蛋白原纤维中肽的排列。(5)随着140 GHz陀螺放大器的开发，我们打算在高场实现一些先进的EPR技术。

DESCRIPTION (provided by applicant): The proposed research is focused on high frequency dynamic nuclear polarization (DNP)/NMR, electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR). We plan CW and pulsed DNP experiments and primarily time domain EPR and ENDOR spectroscopy. The research will develop new magnetic resonance technology and methodology, and address structural questions in a number of interesting biochemical systems. DNP: The DNP experiments can be divided into four (4) areas of endeavor. (1) CW MAS-DNP focuses on the design and construction of equipment to complete a 460 GHz/700 MHz DNP/NMR spectrometer and on applications of DNP to structural biology of membrane and amyloid proteins, the soluble protein GB1 and 17O MQMAS experiments. (2) T-Jump DNP experiments for enhancing NMR signals in spectra of liquids will be developed further. (3) Biradical polarizing agents will be synthesized to improve the efficiency of DNP. (4) Pulsed DNP experiments are planned that will enhance the efficiency of electron-nuclear polarization transfer. EPR/ENDOR: We plan to address questions in five (5) areas with EPR and ENDOR. (1) We propose to develop a simple method for spin counting in proteins containing free radicals (2) We plan to develop a freeze quench apparatus and examine the kinetics of formation of short time radical intermediates in RnR chemistry. (3) We will reexamine high field EPR and ENDOR spectra of apogalactose oxidase as a path to understand the identical spectra observed in the "3 minute" intermediate of E441Q RnR and gemcitabine. (4) We plan to determine the alignment of peptides in amyloid fibrils with TOAC labeling. (5) With the development of a 140 GHz gyroamplifier we intend to implement a number of advanced EPR techniques at high field.