Mossbauer Spectroscopy on Nitrogenase Components

固氮酶成分的穆斯堡尔谱

• 批准号: 9406224
• 负责人: Eckard Munck
• 金额: $ 61万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 1999-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9406224&HistoricalAwards=false
• 关键词: Mossbauer; Spectroscopy; Nitrogenase; Components

9406224 Munck Mossbauer and EPR spectroscopy will be used to study a variety of iron-sulfur proteins and synthetic complexes that mimic the active sites of these proteins. The major focus of the proposed studies will be nitrogenase, with particular emphasis on characterizing intermediates of the catalytic reaction. For these studies protein is available that contains one cluster type (either the cofactor centers or the P-clusters) enriched with the Mossbauer isotope 57Fe whereas the other cluster type contains the Mossbauer-silent 56Fe. The availability of such protein will facilitate the data analyses substantially; moreover, it will allow us to probe the electronic structure of both clusters in considerably more detail. It is also proposed to study carbonmonoxide dehydrogenase and two types of hydrogenases. One of the hydrogenases contains the so-called H- cluster, the stoichiometry of which has not yet been determined in any system studied thus far. Finally, theoretical and experimental studies of 3Fe clusters that occur in proteins and synthetic compounds will be continued. %%% The biological system converts annually in excess of 10 million tons of atmospheric nitrogen into ammonia, which is subsequently incorporated into other cell constituents. Since this process is fundamental to agriculture, many biochemists, biophysicists and geneticists have directed much effort to understand this process on the molecular level. The research of our laboratory has provided a major contribution to the clarification of the structure of the metal centers of nitrogenase. While our past research has addressed the structural aspects of two novel metal clusters in this enzyme, future activities will be directed mostly towards understanding the mechanism of the process, i.e. after having defined the structure involved we wish to elucidate the sequential events occurring during nitrogen fixation. Moreover, we wish to provide structural information to inorganic chemists for the design of catalysts that mimic the biological process. Our struggles with nitrogenase have involved complementary studies that lead to the discovery of new clusters and to fundamentally new insights into magnetochemistry. The proposal studies will address the biochemistry of nitrogenase as well as research of a variety of other related proteins. Our studies of the biological compounds will be complemented by studies of suitable chemical models and theoretical modelling. ***

9406224 Munck Mossbauer 和 EPR 光谱将用于研究各种铁硫蛋白和模拟这些蛋白活性位点的合成复合物。 拟议研究的主要重点是固氮酶，特别强调催化反应中间体的表征。 对于这些研究，可用的蛋白质包含一种富含穆斯堡尔同位素 57Fe 的簇类型（辅因子中心或 P 簇），而另一种簇类型包含穆斯堡尔沉默 56Fe。 这种蛋白质的可用性将极大地促进数据分析；此外，它将使我们能够更详细地探测两个团簇的电子结构。 还建议研究一氧化碳脱氢酶和两种类型的氢化酶。 其中一种氢化酶含有所谓的H-簇，其化学计量在迄今为止研究的任何系统中尚未确定。 最后，将继续对蛋白质和合成化合物中出现的 3Fe 簇进行理论和实验研究。 %%% 生物系统每年将超过 1000 万吨大气中的氮转化为氨，随后被纳入其他细胞成分中。 由于这个过程是农业的基础，许多生物化学家、生物物理学家和遗传学家付出了很大的努力来在分子水平上理解这个过程。 我们实验室的研究为固氮酶金属中心结构的阐明做出了重大贡献。 虽然我们过去的研究已经解决了这种酶中两种新型金属簇的结构问题，但未来的活动将主要致力于了解该过程的机制，即在定义了所涉及的结构之后，我们希望阐明固氮过程中发生的连续事件。 此外，我们希望为无机化学家提供结构信息，以设计模拟生物过程的催化剂。 我们与固氮酶的斗争涉及补充研究，这些研究导致了新簇的发现以及对磁化学的全新见解。 该提案研究将涉及固氮酶的生物化学以及各种其他相关蛋白质的研究。 我们对生物化合物的研究将通过对合适的化学模型和理论建模的研究来补充。 ***