S K-EDGE XAS STUDIES AS A PROBE OF ELECTRONIC STRUCTURE/CONTRIBUTION TO FUNCTION

SK-EDGE XAS 研究作为电子结构/功能贡献的探针

• 批准号: 8362398
• 负责人: BRITT HEDMAN
• 金额: $ 0.03万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8362398
• 关键词: Active Sites; Biochemical Reaction; Complex; DNA glycosylase; Electrons; Enzymes; Escherichia coli; Family; Ferredoxin; Funding; Grant; Hydrogen Bonding; Iron; Ligands; Lyase; Metals; Methodology; Modeling; Mono-S; Mutation; National Center for Research Resources; Principal Investigator; Protein Binding; Pyruvate; Radiation; Research; Research Infrastructure; Resources; Series; Site; Solvents; Source; Spectrum Analysis; Structure; Sulfur; System; United States National Institutes of Health; cost; desaturase; dimethyl sulfoxide reductase; electronic structure; enzyme model; protein complex; structural biology; sulfite oxidase

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Ligand K-edge XAS provides a direct probe of ligand metal bonding. We have developed this methodology to investigate the electronic structures of model complexes and protein active-sites of a number of clusters and sites, in particular Fe-S, Cu-S clusters and dithiolene-containing Mo/W sites. In the previous proposal period, among several studies, we evaluated the generality of the difference between HiPIPs and ferredoxins and systematically studied the effect of H-bonding, solvent interaction and effect of changing dielectric field around these and other clusters using well-characterized model complexes and proteins, and combined experimental results with DFT calculation. We have also developed the bonding/geometric structure correlations in the Mo(tris)dithiolenes and the mechanism of oxo trasnsfer in the DMSO reductase family of enzymes and models. In this proposal we plan to extend this methodology, and combine it with complementary spectroscopies, to study several Fe-S systems, such as the interaction of SAM with the Fe4S4 cluster in pyruvate lyase activating enzyme; MutY - a DNA glycosylase from Escherichia coli; Fe2S2 protein binding to ?9 desaturase; and effects of Cys->Ser mutations on electron delocalization in iron sulfur clusters. We also intend to study a series of Mo mono- and bis-oxo bis(dithiolene) complexes that model the states of the sulfite oxidase family. The specific aim is to define the electronic structure of enzymes and model complexes and understand the correlations between structure and function of enzymatic reactions.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 配体 K 边缘 XAS 提供了配体金属键合的直接探针。我们开发了这种方法来研究模型复合物的电子结构以及许多簇和位点的蛋白质活性位点，特别是 Fe-S、Cu-S 簇和含二硫醇的 Mo/W 位点。在之前的提案期间，在多项研究中，我们评估了 HiPIP 和铁氧还蛋白之间差异的普遍性，并使用充分表征的模型复合物系统地研究了氢键作用、溶剂相互作用以及改变这些簇和其他簇周围介电场的影响和蛋白质，并将实验结果与DFT计算相结合。 我们还开发了 Mo(三)二硫烯中的键合/几何结构相关性以及 DMSO 还原酶家族和模型中的氧转移机制。 在本提案中，我们计划扩展该方法，并将其与互补光谱相结合，研究几种 Fe-S 系统，例如 SAM 与丙酮酸裂合酶激活酶中 Fe4S4 簇的相互作用； MutY - 来自大肠杆菌的 DNA 糖基化酶； Fe2S2 蛋白与 ?9 去饱和酶结合；以及 Cys->Ser 突变对铁硫簇中电子离域的影响。 我们还打算研究一系列模拟亚硫酸盐氧化酶家族状态的钼单氧双（二硫烯）配合物。 具体目标是定义酶和模型复合物的电子结构，并了解酶反应的结构和功能之间的相关性。