A Biosynthetic Approach Toward Biomimetic Studies of Metalloproteins Involved in Long-range Electron Transfer

伊利诺伊大学香槟分校陆毅教授的这项研究得到了无机、生物无机和有机金属化学项目的支持。这项工作的目的是阐明每个配体的作用，人工引入铜，Cu-A，中心的蔚蓝蛋白，在自然界中，包含一个单核铜位点。这将有助于确定配体对Cu-A中心几何参数、电子结构和行为的影响，这些对重要的电荷转移蛋白（如色素氧化酶）的功能至关重要。此外，本研究还对blue (type 1) copper、Cu-A和Fe2S2这三种重要的电子转移中心的结构和功能特性进行了直接比较。二铁中心将通过一种新技术——表达蛋白连接（EPL）——插入到蓝蛋白中，该技术有望成为一种非常有效和经济的方式，以产生含有非天然氨基酸的毫克级蛋白质。电子转移蛋白对基本生命过程至关重要。在这种蛋白质中人工放置的不寻常的Cu-A位点周围的各种氨基酸的影响将被系统地确定，并与正常的蓝铜位点和另一种双金属位点Fe2S2（也存在于必需的电子转移蛋白中）的影响进行比较。

This research by Professor Yi Lu of the University of Illinois at Urbana-Champaign is supported by the Inorganic, Bioinorganic and Organometallic Chemistry program. The goal of this work is to elucidate the role of each ligand of an artificially introduced dicopper, Cu-A, center in azurin, which, in nature, contains a mononuclear copper site. This will enable determining ligand effects on geometric parameters, electronic structure and behavior of the Cu-A center, which are essential to the function of important charge-transfer proteins, such as cyctochrome oxidase. In addition, this study provides for the direct comparison of the structural and functional properties of three important electron transfer centers: blue (type 1) copper, Cu-A and Fe2S2. The di-iron center will be inserted into the azurin by a new technique, expressed protein ligation (EPL), which shows promise as a very efficient and cost-effective way to generate milligram quantities of proteins containing unnatural amino acids.Electron-transfer proteins are vital to fundamental life processes. The effects of the various amino acids surrounding the unusual Cu-A site artificially placed in this protein will be systematically determined and compared with that of the normal blue copper site and another two-metal site, Fe2S2, which also occurs in essential electron-transfer proteins.