Nickel Superoxide Dismutase

镍超氧化物歧化酶

• 批准号: 0809188
• 负责人: Michael Maroney
• 金额: $ 37.6万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0809188&HistoricalAwards=false
• 关键词: Nickel; Superoxide; Dismutase

This award in the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Professor Michael Maroney at the University of Massachusetts to understand the role of the protein in creating the active site in recombinant Streptomyces coelicolor nickel superoxide dismutase (NiSOD). Point mutations will be employed to address the following questions: 1. Do residues in the second coordination sphere of Ni play a critical role in optimizing the redox potential of the active site? 2. Is the quaternary structure required for catalysis? 3. What are the roles of conserved tyrosine residues near the active site? 4. How does the protein structure moderate the interaction of the active site with hydrogen peroxide, a molecule that is a reaction product, an active site reductant, and readily oxidizes thiolates, such as the cysteine ligands found in the active site? Mutant enzymes will be characterized using a strategy that employs a variety of complementary biophysical techniques including EPR and x-ray absorption spectroscopy. The effect of mutations on catalysis will be addressed by measuring the catalytic rate constant and examining the reaction mechanism using pulse radiolytic generation of superoxide and UV-Vis spectroscopy, and by assessing the redox potential of the enzyme using redox titrations. Mutations that result in a perturbed mechanism will be further examined using crystallography. Catalytic intermediates that have been detected in a number of existing mutant NiSODs will be freeze-trapped and examined spectroscopically The study of NiSOD will contribute to the understanding of redox catalysis by biological nickel sites. The research will provide multidisciplinary training at the interface of chemistry and biology for students at all levels (undergraduate through post-doctoral).

无机，生物无机和有机化学计划的这一奖项支持马萨诸塞州大学的Michael Maroney教授的研究，以了解蛋白质在重组天蓝色链霉菌镍超氧化物歧化酶（NiSOD）中创造活性位点的作用。点突变将被用来解决以下问题：1。残基在第二配位领域的镍发挥关键作用，优化氧化还原电位的活性位点？2.催化需要四级结构吗？3.活性位点附近的保守酪氨酸残基有什么作用？4.蛋白质结构如何调节活性位点与过氧化氢的相互作用，过氧化氢是一种反应产物，活性位点还原剂，并且容易氧化硫醇盐，如活性位点中发现的半胱氨酸配体？突变酶将采用一种策略，采用各种互补的生物物理技术，包括EPR和X射线吸收光谱的特点。突变对催化作用的影响将通过测量催化速率常数和使用脉冲辐解产生的超氧化物和紫外-可见光谱检查反应机制，并通过使用氧化还原滴定评估酶的氧化还原电位来解决。将使用晶体学进一步检查导致扰动机制的突变。催化中间体已被检测到在一些现有的突变NiSOD将被冷冻捕获和光谱检查NiSOD的研究将有助于了解氧化还原催化的生物镍网站。该研究将在化学和生物学的接口为各级学生（通过博士后本科）提供多学科培训。