EPR AND ENDOR OF PARAMAGNETIC BIOMOLECULES

我们的总体目标是了解生物系统如何包含 顺磁中心起作用了。我们将探测顺磁中心以 确定局部配位结构，共享不成对电子 分布，以及蛋白质诱导扰动的证据。我们会 通过电子技术初步研究这些中心 顺磁共振(EPR)和电子核双共振 (恩多)。除了EPR/Endor，我们还将带来互补的动力学和 根据需要采用光谱分析方法。拟研究的系统包括： 1.亚硝酸还原酶。这项工作旨在了解其催化机理。 在将亚硝酸盐还原为硝酸盐的过程中，亚硝酸还原酶中的2型铜 氧化物。 2.含铁博莱霉素与DNA的相互作用。这样做的目的是 研究将建立在我们最近的Endor研究的基础上，该研究表明 博莱霉素铁与邻近DNA底物的相互作用。我们会做得更多 完全描绘出博莱霉素与DNA原子的亲和力 了解轴向含氮配体与 博莱霉素铁。 3.DNA修复酶以Mn++为中心。这项工作的计划是探索 核酸内切酶III和核酸外切酶IV，2的MN+中心活性中心 识别DNA碱基受损或丢失并断裂的大肠杆菌蛋白 DNA磷酸盐的骨架。MN++与底物的相互作用 活性中心附近突变对活性中心结构的扰动 场地将由恩多划定。 4.光合作用多锰中心。这项工作旨在探索 用高灵敏度Q波段Endor获得多锰心 关于可交换17/O-水和质子以及中心和TO信息 了解所需的氯离子和钙离子的结构基础 中心的功能。 5.高自旋铁血红素配位环境在氧- 末端氧化酶的消费中心。这项工作的计划是揭开 双核血红素第6配基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.