XRAY ABSORPTION SPECTROSCOPY OF METAL SUBSTITUTED IRON SULFUR CLUSTER

狂热杆菌铁氧还蛋白是世界上唯一的铁氧还蛋白 具有单个Fe4S4团簇，其中一个铁具有非硫 协调。这种蛋白质的一个不同寻常的特征是易于与 团簇可以失去这个铁来形成Fe3S4铁还蛋白。这个 Fe3S4铁氧还蛋白可以很容易地与Fe2重组，以改造 天然Fe4S4团簇，或与其他金属离子选择性地 生成混合金属铁硫团簇MFe3S4。混合金属铁 硫团簇是一类非常重要的金属蛋白 活跃的遗址，并具有相当大的兴趣。我们建议使用XAS 为了系统地探索分子的电子结构和物理结构 热还蛋白中不同的MFe3S4簇。

Pyrococcus furiosus ferredoxin is unique among ferredoxins in having a single Fe4S4 cluster with one iron possessing non-sulfur coordination. An unusual feature of the protein is the ease with which the cluster can lose this iron to form a Fe3S4 ferredoxin. The Fe3S4 ferredoxin can readily be reconstituted with Fe2+ to reform the native Fe4S4 cluster, or alternatively with other metals ions to generate a mixed-metal iron sulfur cluster MFe3S4. Mixed metal iron sulfur clusters comprise a very important class of metalloprotein active sites and are of considerable interest. We propose to use XAS to systematically probe the electronic and physical structure of the different MFe3S4 clusters in Pyrococcus furiosus ferredoxin.