SYNTHESIS OF NOVEL IRON & MIXED METAL-SULFUR CLUSTERS

铁是蛋白质和蛋白质中最常见的过渡金属 在所有生物中参与许多基本的生理功能 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-硫团簇是极其重要的，而不是 不仅因为它们的无处不在，还因为它们独特的氧化还原作用 属性。铁的结合和稳定机制 对这些结构的了解还远远不够。厌氧症 细菌对人类的疾病和健康都很重要， 构成了铁硫团簇的极好来源，含有 蛋白质，因此，是他们研究的理想工具。 这项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化机理 在某些铁氧还蛋白中的发现及其对调控的意义 多个电子转移链中的电子流动。对.的使用 铁氧还蛋白和人工调节多肽作为模板 新的混合金属团簇的合成也将作为一个 开发新分子和检测其潜在催化作用的手段 属性。 本研究的具体目的是：1)制备新型混合金属 巨硫弧菌铁氧还蛋白II(Co-Fe)中的团簇 并且已经从该蛋白质中获得了锌-铁簇；2)到 寻找其他的铁氧还蛋白，它们的表现可能会好于D。 蛋白质在合成这些新金属簇中的作用；3)制备 特别标记的同位素，57Fe或56Fe铁-硫 并使用不同的光谱方法研究它们的性质 技术；4)克隆并在大肠杆菌中表达铁氧还蛋白基因 为了过量生产用于物理研究的蛋白质，也为了 能够进行定点突变以理解3Fe和4Fe是如何 硫团簇形成并稳定；5)进行生理 用转化的混合金属团簇和突变的 蛋白质；6)将这些技术扩展到含复杂金属的 酶；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.