EPR-ENDOR OF PARAMAGNETIC PROTEINS OF ELECTRON TRANSPORT

我们的目标是了解顺磁的基本电子结构 金属和自由基蛋白质，了解自然之间的相互作用 发生顺磁中心的蛋白质，并探测动力学 顺磁中心运动 拟议工作的结果将是一个更 完全理解顺磁中心在其 生物角色。 本研究的具体目标是：1.研究细胞色素 P-450通过电子核双共振（ENDOR）测定其血红素配体 环境 2.用ENDOR方法研究卟啉连接的电子结构 铁血红蛋白、coboglobins和亚硝酰基中的氮和质子 血红蛋白，以检测构象变化的影响。 3.用…探测 ENDOR在细胞色素c中EPR可检测到的“铜”和血红素的周围 氧化酶和发现性质的泛半醌自由基在一个新的 发现了电子传递链的自由基泛醌蛋白。 4.探讨 用脉冲EPR和饱和转移EPR证明金属间化合物 相互作用和金属间距离。 5. 寻找 与coboglobins结合的O2的缓慢分子运动和 泛醌在其蛋白质环境中。 脉冲EPR和饱和转移EPR 将用于 为了进行这些实验，我们目前有一个工作的ENDOR光谱仪， 饱和转移EPR的调制。 脉冲饱和恢复 现在正在建造一种装置来监测电子自旋晶格弛豫， 将建造一个磁场脉冲装置，与它一起工作， 一部分是拟议中的工作。

Our goal is to understand the fundamental electronic structure of paramagnetic metal and free radical proteins, to understand the interaction between naturally occuring paramagnetic centers in proteins, and to probe the dynamics of paramagnetic center motion. The outcome of the proposed work will be a more complete understanding of how the paramagnetic centers perform in their biological roles. The specific goals of the proposed research will be: 1. To study Cytochrome P-450 by electron nuclear double resonance (ENDOR) to determine its heme ligand environment. 2. To study by ENDOR the electronic structure at porphyrin-linked nitrogens and protons in ferric hemoglobins, coboglobins, and nitrosyl hemoglobins in order to detect effects of conformational change. 3. To probe by ENDOR the environs of the EPR-detectable "copper" and heme in cytochrome c oxidase and to discover the nature of the ubisemiquinone radical in a newly found radical-ubiquinone protein of the electron transport chain. 4. To probe with pulsed EPR and saturation transfer EPR for evidence of inter-metal interaction and inter-metal distances in cytochrome c oxidase. 5. To look for the effect of slow molecular motions of O2 bound to coboglobins and of the ubiquinone in its protein environment. Pulsed EPR and saturation transfer EPR will be used. To perform these experiments we presently have a working ENDOR spectrometer and modicications for saturation transfer EPR. A pulsed saturation recovery apparatus is now being built to monitor electron spin-lattice relaxation, and a magnetic field pulsing device to operate in conjunction with it will be built as a part of the proposed work.