EPR AND ENDOR OF PARAMAGNETIC BIOMOLECULES

描述(改编自申请人的摘要)：这项工作的总体目标 研究是为了了解含有顺磁中心的蛋白质是如何 工作。申请者将探索顺磁中心的结构 它们本身，中心之间的相互作用，以及相互关系 在中心的结构和它的蛋白质环境之间。这个 选择进行研究的系统是一种识别和切除损伤的蛋白质 从DNA中消除潜在的突变，连接转移的蛋白质 电子在线粒体中产生生物有用的能量，以及 蛋白质及其催化生物氧化的模型。这个 申请者将专注于探索这些中心，主要通过 电子顺磁共振(EPR)技术(脉冲和连续) 和电子核双共振(Endor)，并大量使用其他 光谱和动力学方法。申请人的实验室是以下实验室之一 世界上少数几个经常使用恩多测量超精细的 生物分子中电子自旋的耦合。具体的 要研究的系统是：(1)大肠杆菌的核酸内切酶III，它是一种DNA 修复酶，由于申请人打算发现的原因， 一个铁硫中心。(2)细胞色素c氧化酶，它与 电子到分子氧的转移，以生物方式生产 有用的能量。申请者打算探索电子机制 顺磁性金属的这种耦合。(3)线粒体细胞色素Bc1 复合体，它还耦合了电子通过其 顺磁以生物有用能量的产生为中心。这个 申请者打算探索自由基和顺磁性的结构 Bc1复合体中的金属。(4)细胞色素c过氧化物酶，催化 过氧化氢还原的细胞色素c的消耗。在消费中 过氧化氢，这种酶会产生一种不寻常的顺磁性中间体 申请人将通过使用磁共振来描述其特征 基因操纵蛋白质的技术。(5)现役军人模特 催化底物氧化的铜蛋白质的位置或 可逆地结合氧气。由于模型结构多种多样，申请人 将研究由此产生的对电子结构的扰动。

DESCRIPTION (Adapted from applicant's abstract): The overall goal of this research is to understand how proteins that contain paramagnetic centers work. The applicant will probe the structure of the paramagnetic centers themselves, the interaction between the centers, and the correlation between the structure of the center and its protein surroundings. The systems chosen for study are a protein that recognizes and excises damages from DNA to eliminate potential mutations, proteins that couple transfer of electrons to production of biologically useful energy in mitochondria, and proteins and their models that catalyze biological oxidations. The applicant will focus on probing these centers primarily through the techniques of electron paramagnetic resonance (EPR) (pulsed and continuous) and electron nuclear double resonance (ENDOR) with significant use of other spectroscopic and kinetic methods. The applicant's laboratory is one of the few in the world which routinely uses ENDOR to measure hyperfine couplings of the electron spins in biological molecules. The specific systems to be studied are: (1) Endonuclease III of E. coli which is a DNA repair enzyme that contains, for reasons the applicant intends to discover, an iron-sulfur center. (2) Cytochrome c oxidase, which couples the transfer of electrons to molecular oxygen to the production of biologically useful energy. The applicant intends to probe the electronic mechanisms of this coupling at paramagnetic metals. (3) The mitochondrial cytochrome bc1 complex, which also couples the transfer of electrons through its paramagnetic centers to production of biologically useful energy. The applicant intends to probe the structure of free radicals and paramagnetic metals in the bc1 complex. (4) Cytochrome c peroxidase, which catalyzes the consumption of reduced cytochrome c by peroxide. In consuming peroxide, this enzyme gives rise to an unusual paramagnetic intermediate which the applicant will characterize by using magnetic resonance techniques on genetically manipulated protein. (5) Models for the active sites of copper proteins which catalyze oxidation of substrates or reversibly bind oxygen. As the model structure is varied, the applicant will study the resultant perturbations to electronic structure.