Models for the FeMo-Cofactor of Nitrogenase

固氮酶 FeMo 辅因子模型

• 批准号: 8901474
• 负责人: Bruce Averill
• 金额: $ 36.53万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-05-15 至 1994-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8901474&HistoricalAwards=false
• 关键词: Models; FeMo; Cofactor; Nitrogenase

The objective of this project in the Inorganic, Bioinorganic and Organometallic Chemistry Program is the synthesis and characterization of compounds consisting of clusters of molybdenum, iron and sulfur atoms. Such clusters are related to the iron-molybdenum cofactor, familiarly known as FeMo-co, of the enzyme nitrogenase. This cofactor, which has a currently unknown structure, constitutes a key portion of the enzyme's active site. Studies of the target compounds are needed in order to assess those aspects of the structural and chemical properties of FeMo-co which are essential to the "fixing" of atmospheric nitrogen through reduction by the enzyme. Nitrogenase catalyzes one of the most complex multi-electron transfer reactions in biology, so that understanding the structure and reactivity of its active site is of fundamental chemical and biochemical importance. Further, a catalytic cluster resembling the active site may be a powerful catalyst for a variety of chemical transformations. Systematic syntheses of high nuclearity Mo-Fe-S clusters will be explored. Emphasis will be placed on controlling the structural reorganizations that occur during oxidative decarbonylation reactions in order to prepare new Mo-S-Fe clusters that may mimic FeMo-co structurally and which will bind small molecules that are nitrogenase substrates or inhibitors in dinitrogen reduction. The synthetic species will be characterized by chemical and physical methods, and their reactivities will be investigated, with emphasis on a systematic examination of the reactivity of the different metal sites within a given cluster.

该项目在无机、生物无机和有机金属化学计划中的目标是合成和表征由钼、铁和硫原子簇组成的化合物。这些簇与固氮酶的铁钼辅因子（通常称为 FeMo-co）有关。该辅因子的结构目前未知，它构成了酶活性位点的关键部分。需要对目标化合物进行研究，以评估 FeMo-co 的结构和化学性质，这些方面对于通过酶还原“固定”大气氮至关重要。 固氮酶催化生物学中最复杂的多电子转移反应之一，因此了解其活性位点的结构和反应性具有基本的化学和生物化学重要性。此外，类似于活性位点的催化簇可能是多种化学转化的强大催化剂。 将探索高核Mo-Fe-S团簇的系统合成。重点将放在控制氧化脱羰反应过程中发生的结构重组，以制备新的Mo-S-Fe簇，该簇可以在结构上模仿FeMo-co，并且将结合作为固氮酶底物或二氮还原抑制剂的小分子。合成物质将通过化学和物理方法进行表征，并将研究它们的反应性，重点是对给定簇内不同金属位点的反应性进行系统检查。