EPR AND ENDOR OF PARAMAGNETIC BIOMOLECULES

我们的总体目标是了解生物系统如何包含 顺磁中心起作用。我们将探测顺磁中心， 确定局部配位结构，共享未成对电子 分布和蛋白质诱导扰动的证据。我们将 通过电子显微镜技术对这些中心进行了初步研究， 顺磁共振和电子核双共振 （ENDOR）。除了EPR/ENDOR，我们还将带来互补的动能和 光谱方法，以承担需要。拟研究的系统为： 1.亚硝酸还原酶。这项工作旨在了解催化机制 亚硝酸盐还原酶中的2型铜，因为它将亚硝酸盐还原为硝酸盐 环氧 2.含铁博莱霉素与DNA的相互作用的目的 研究将建立在我们最近的ENDOR研究的基础上，该研究表明， 博来霉素铁与邻近DNA底物相互作用。我们将更加 完全描绘了博莱霉素与DNA原子的接近程度， 为了理解轴向含氮配体的身份， 博莱霉素铁。 3. DNA修复酶中的MN ++中心。这项工作的计划是探索 核酸内切酶III和核酸外切酶IV的以MN ++为中心的活性位点， e.大肠杆菌蛋白质识别DNA与损坏或丢失的基地和打破 DNA磷酸骨架。MN ++与底物的相互作用， 来自活性位点附近突变的活性位点结构的扰动 研究中心将由ENDOR划定。 4.多锰光合作用中心。这项工作旨在探索 用高灵敏度的多锰中心Q波段ENDOR获得 关于可交换~（17）O-水和质子以及中心和 了解所需的Cl-和Ca ++的结构基础， 中心的功能。 5.高自旋铁血红素配位环境在氧- 末端氧化酶的消耗中心。这项工作的计划是揭示 双核配体的第6位血红素配体及其附近的配位环境 BO氧化酶的耗氧中心。

Our overall goal is to understand how biological systems that contain paramagnetic centers work. We will probe the paramagnetic centers to determine local liganding structure, shared unpaired electron distribution, and evidence for protein-induced perturbation. We will investigate these centers primary through the techniques of electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR). Besides EPR/ENDOR we will bring complementary kinetic and spectroscopic methods to bear as needed. The systems to be studied are: 1. Nitrite Reductase. This work aims to understand the catalytic mechanism of the Type 2 copper in nitrite reductase as it reduces nitrite to nitric oxide. 2. Fe-containing Bleomycin Interacting with DNA. The objective of this study will be to build upon our recent ENDOR study that showed the interaction of bleomycin iron with nearby DNA substrate. We will more completely delineate the proximity of bleomycin to DNA atoms and work toward understanding the identity of the axial nitrogenous ligand to the bleomycin iron. 3. MN++ Centers in DNA Repair Enzymes. The plan for this work is to probe the MN++-centered active sites of Endonuclease III and Exonuclease IV, two E. coli proteins which recognize DNA with damaged or lost bases and break the DNA phosphate backbone. Interaction of the MN++ with substrate and perturbation of the active site structure from mutations near the active site will be delineated by ENDOR. 4. Multimanganese Center for Photosynthesis. This work is aimed at probing the multimanganese center with high sensitivity Q-band ENDOR to obtain information on exchangeable 17/O-water and protons and that center and to understand the structural basis of the required Cl- and Ca++ in the function of the center. 5. ENDOR of the High Spin Ferric Heme Liganding Environment at the Oxygen- Consuming Center of Terminal Oxidase. The plan of this work is to uncover the liganding environment at and near the 6th heme ligand of the binuclear oxygen-consuming center of bo oxidase.