Stereoselectivity in Metalloprotein Electron Transfer

在无机、生物无机和有机金属化学项目的支持下，John R. Pladziewicz博士将研究金属蛋白的电子转移反应在多大程度上取决于其他反应物的三维结构。将比较金属蛋白与光学异构体反应的电子转移速率，光学异构体是指含有相同原子以相同方式连接的分子，但它们的三维结构不同，因此它们是不可重叠的镜像。该项目的结果可能有助于解释许多生物电子转移反应所表现出的精细选择性。该项目的主要目标是：(1)研究金属蛋白和手性配位化合物之间的一系列电子转移反应，以期确定几种可检测到立体选择性电子转移的反应。(2)测量这些反应的立体选择性程度。(3)确定前体络合物中立体选择性金属蛋白-配位化合物离子配对对观察到的电子转移立体选择性的贡献程度。(4)确定供体-受体距离和取向对观察到的立体选择性的影响程度。(5)基于现有的x射线晶体学数据和观察到的选择性建立模型，以促进对生物电子转移的立体化学控制的理解。

With support from the Inorganic, Bioinorganic and Organometallic Chemistry Program Dr. John R. Pladziewicz will investigate the extent to which electron-transfer reactions of metalloproteins depend on the three-dimensional structure of the other reactant. Rates of electron transfer will be compared for metalloproteins reacting with optical isomers, i.e., molecules which contain the same atoms connected in the same way, but which differ in their three-dimensional structures so that they are non-superposable mirror images. The results of the project may help explain the exquisite selectivity exhibited by many biological electron-transfer reactions. The principal objectives of the project are to: (1) Examine a series of electron-transfer reactions between metalloproteins and chiral coordination compounds with the expectation of identifying several reactions for which stereoselective electron transfer is detectable. (2) Measure the extent of stereoselectivity in these reactions. (3) Determine the extent to which stereoselective metalloprotein-coordination compound ion pairing in the precursor complex contributes to any observed electron-transfer stereoselectivity. (4) Determine the extent to which donor-acceptor distance and orientaion play a role in observed stereoselectivity. (5) Develop models based on available x-ray crystallographic data and observed selectivity to advance understanding of the stereochemical control of biological electron transfer.