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

这个合作项目的重点是阐明碳酸氢盐的作用 (BC)水氧化酶（WOC）的功能/结构组织。 我们合作产生的先前联合研究表明，BC是一个关键 组装WOC的无机核所需的组分，特别是 Mn 2+离子的结合和光氧化。BC也有潜力 对理解无机岩芯生物成因的意义 在第一个产生O2的光合生物的进化过程中。到 研究BC直接相互作用（连接）的可能性， WOC、EPR、ENDOR、ESE-ENDOR和FT-1 R的（Mn 4Ca 1Clx）核心 在更换12个BC后，将研究堆芯的特性 C-和13 C-甲酸盐、13 C-碳酸氢盐和硼酸盐 来自apo-WOC制剂的WOC和无机辅因子。可能发挥的作用 BC在四电子（产生02）与四电子（产生02）之间的“切换”中， 水氧化的双电子（产生H2 O2）机制，将是 使用鲁米诺-过氧化物酶测定法（其灵敏度 在俄罗斯，这一比例大幅上升）。BC在以下方面可能发挥的作用： 还将检测WOC的过氧化氢酶活性。电化学 锰络合物与BC和其他弱阴离子，以及它们的能力， 向WOC提供电子，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。包括人类在内的所有需氧生物的健康 在这些过程中，由于水氧化是主要的可再生能源， 空气中的氧，而过氧化氢酶保护免受氧化损伤所造成的 过氧化氢，一种强有力的生物毒素。该项目的具体目标 与NIH的母项目“过氧化氢酶和 光合水氧化酶“这项研究将主要在俄罗斯进行， NIH补助金#5R01GM39932- 1 O延期