SYNTHESIS OF NOVEL IRON & MIXED METAL-SULFUR CLUSTERS

铁是蛋白质中最常见的过渡金属， 参与所有生物的许多基本生理功能 生物，特别是在与节能有关的过程中。 在真核生物常见的含铁结构中， 和原核生物一样，铁硫簇是非常重要的， 不仅是因为它们的普遍性，还因为它们独特的氧化还原作用 特性. 铁的掺入和稳定机制 对这些结构的理解还远远不够。 厌氧 细菌对人类的疾病和健康都很重要， 构成含铁-硫簇合物的优良来源 蛋白质，因此是研究它们的理想工具。 本研究项目的长期目标是了解 三个和四个含铁团簇之间的转换机制 在某些铁氧化还原蛋白中发现， 在多电子转移链中的电子流动。 使用 铁氧还蛋白和人工再合成的多肽作为模板， 新的混合金属簇合物的合成也将被探索作为一种 开发新分子并检查其潜在的催化活性 特性. 本研究的具体目标是：1）制备新型的混合金属 簇掺入脱硫弧菌gigas铁氧还蛋白II（Co-Fe 和Zn-Fe簇已经从该蛋白质中获得; 2） 寻找其他铁氧化还原蛋白，可以比D. gigas 蛋白质合成这些新的金属簇; 3）制备 特别是同位素标记的57 Fe或56 Fe铁硫 集群和研究他们的性质，使用不同的光谱 技术; 4）克隆表达D. gigas铁氧还蛋白基因在E.杆菌 为了过量生产蛋白质用于物理研究， 能够进行定点突变，以了解3Fe和4Fe 硫簇的形成和稳定; 5）进行生理 用转化的混合金属簇和突变的 6）将这些技术扩展到含金属的复合物 7）使用现代计算机监控上述实验 图形建模

Iron is the most common transition metal found in proteins and participates in many fundamental physiological functions in all living organisms, in particular in processes related to energy conservation. Among the iron-containing structures which are common to eucaryotes as well as procaryotes, iron-sulfur clusters are extremely important, not only because of their ubiquity, but also because of their unique redox properties. The mechanisms of incorporation and stabilization of iron into these structures is still far from being well understood. Anerobic bacteria, which are important to man in disease and in health, constitute an excellent source of iron-sulfur cluster containing proteins and, as such, are ideal tools for their study. The long term objective of this research project is to understand the conversion mechanisms between three and four iron-containing clusters found in certain ferredoxins and their significance for the regulation of electron flow in multiple electron transfer chains. The use of ferredoxins and artificially reconceived polypeptides as templates for the synthesis of new mixed-metal clusters will also be explored as a means to develop new molecules and examine their potential catalytic properties. Specific aims of this research are: 1) to prepare new mixed-metal clusters incorporated into Desulfovibrio gigas ferredoxin II (a Co-Fe and a Zn-Fe cluster have already been obtained from this protein; 2) to search for other ferredoxins that could perform better than the D. gigas protein in the synthesis of these new metal clusters; 3) to prepare specifically isotope-labelled, either 57 Fe or 56 Fe iron-sulfur clusters and investigate their properties using different spectrometric techniques; 4) to clone and express D. gigas ferredoxin gene in E. coli in order to over-produce the protein for physical studies and also to be able to perform site-directed mutagenesis to understand how 3Fe and 4Fe sulfur clusters are formed and stabilized; 5) to perform physiological experiments with the transformed mixed-metal clusters and the mutated proteins; 6) to extend these techniques to complex metal-containing enzymes; 7) to monitor the above experiments using modern computer graphics modeling.