Bicarbonate as a New Cofactor of Water Oxidase

碳酸氢盐作为水氧化酶的新辅因子

• 批准号: 6335821
• 负责人: G CHARLES DISMUKES
• 金额: $ 3.82万
• 依托单位: PRINCETON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-01 至 2002-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6335821
• 关键词: Commonwealth of Independent States; Raman spectrometry; X ray crystallography; bicarbonates; calcium ion; carbon; catalase; chemical structure function; cofactor; cooperative study; electrochemistry; electron nuclear double resonance spectroscopy; electron spin resonance spectroscopy; enzyme activity; hydrogen peroxide; infrared spectrometry; interferometry; manganese; nuclear magnetic resonance spectroscopy; oxidation; peroxidases; ruthenium; strontium; water

This collaborative project is focused on elucidation of the role of bicarbonate (BC) in the functional/structural organization of the water oxidase (WOC). Prior joint studies arising from our collaboration has shown that BC is a key component needed for assembly of the inorganic core of the WOC, particularly the binding and photo-oxidation of Mn 2+ ions. BC also has potential significance for understanding the origin of biogenesis of the inorganic core during evolution of the first 02 producing photosynthetic organisms. To investigate the possibility of direct interaction (ligation) of BC to the (Mn4Ca1Clx) core of the WOC, the EPR, ENDOR, ESE-ENDOR and FT-lR characteristics of the core will be investigated after replacement of BC for 12 C- and 13C-formate, 13C- bicarbonate and borate during reconstitution of the WOC from apo-WOC preparations and the inorganic cofactors. A possible role for BC in "switching" between the four-electron (with production of 02) to the two-electron (with production of H202) mechanism of water oxidation, will be investigated using the luminol-peroxidase assay (the sensitivity of which has been considerably increased in the Russian group). A possible role for BC in the catalase activity of the WOC will also be examined. Electrochemistry of manganese complexes with BC and other weak anions, and their capabilities to donate electrons to the WOC and to catalyse the decomposition of hydrogen peroxide will be studied to understand the specificity of the bicarbonate effect on the WOC. The health of all aerobic organisms, including man, depends upon these processes, since water oxidation is the dominant renewable source of atmospheric oxygen, while catalase protects against oxidative damage caused by hydrogen peroxide, a potent biological toxin. The specific aims of this project are directly related to the aims of the parent NIH project "Catalases and photosynthetic water oxidase." The research will be mainly done in Russia as an extension of NIH grant #5R01GM39932-1O

该协作项目的重点是阐明碳酸氢盐的作用 （BC）在水氧化酶（WOC）的功能/结构组织中。 我们的合作提出的先前的联合研究表明，卑诗省是关键 组装WOC的无机核心所需的组件，特别是 Mn 2+离子的结合和光氧化。卑诗省也有潜力 理解无机核生物发生的起源的意义 在第一个02产生光合有机体的进化过程中。到 调查BC直接相互作用（连接）与 （MN4CA1CLX）WOC的核心，EPR，Endor，ESE-Endor和FT-LR 核心的特征将在更换BC后进行12 C-和13C形成型，13c-碳酸氢盐和硼酸盐在重组期间 来自APO-WOC制剂和无机辅助因子的WOC。可能的角色 BC在四电子之间的“切换”（并产生02）到 两电子（与H202的产生）水氧化机理将是 使用Luminol-过氧化物酶测定法进行了研究（其灵敏度的敏感性 在俄罗斯集团中有了很大的增加）。卑诗省可能的角色 还将检查WOC的过氧化氢酶活性。电化学的 具有卑诗省和其他弱阴离子的锰综合体及其能力 向WOC捐赠电子并催化氢的分解 将研究过氧化物以了解碳酸氢盐的特异性 对WOC的影响。包括人在内的所有有氧生物的健康都取决于 在这些过程中，由于水氧化是主要的可再生能源 大气中的氧气，而过氧化氢酶可预防由 过氧化氢，一种有效的生物毒素。该项目的具体目的 与父母NIH项目的目标直接相关 光合水氧化酶。“这项研究将主要在俄罗斯进行 NIH赠款的扩展＃5R01GM39932-1O