METHANE MONOOXYGENASE STRUCTURE/FUNCTION

描述：PI建议调查3D结构，活动站点 可溶物的结构、催化机理和活化机理 甲氧菌II型甲烷单加氧酶的研究 毛孢霉OB3b.这种酶催化氧化的第一步 产甲烷细菌将甲烷转化为二氧化碳。通过这种方式，大气层 几乎所有数量巨大的生物甲烷(一种有效的 防止了厌氧细菌产生的温室气体)。MMO还 意外地催化许多其他碳氢化合物的氧化，导致 在合成和生物降解方面的应用。迄今为止的研究表明 该反应是由其他加氧酶中没有的辅因子催化的， 意味着一种新的氧活化策略。建议的研究建立 关于在前一次供资方面取得的非常重大的进展 期间，重点是：物理和电子结构的阐明 活性中心的双核铁团簇的性质以及反应机理 由该中心催化的氧活化；光谱和动力学 几种反应中间体的表征 在催化序列中鉴定；蛋白质-蛋白质的阐明 调节其功能的酶的三种多肽之间的相互作用 催化活性。

DESCRIPTION: The PI proposes to investigate the 3D structure, active site architecture, catalytic mechanism and mechanism of activation of soluble methane monooxygenase from the Type II methanotroph Methylosinus trichosporum OB3b. This enzyme catalyzes the first step in the oxidation of methane to CO2 by methanogenic bacteria. In this way, the atmospheric egress of nearly all the enormous quantity of biogenic methane (a potent greenhouse gas) generated by anaerobic bacteria is prevented. MMO also adventitiously catalyzes the oxidation of many other hydrocarbons leading to applications in synthesis and biodegradation. Work to date suggests that the reaction is catalyzed by a cofactor not found in other oxygenases, implying a new strategy for oxygen activation. The proposed studies build on the very significant progress that has been made in the previous funding period, and focus on: elucidation of the physical and electronic structure of dinuclear iron cluster of the active site as well as the mechanism of oxygen activation catalyzed by this center; spectroscopic and kinetic characterization of the several reaction intermediates that have been identified in the catalytic sequence; elucidation of the protein-protein interactions between the three polypeptides of the enzyme that modulate its catalytic activity.