Kinetics and Mechanisms of Fe(III) and Cu(II) Reduction by Heme Proteins

这是一个由生命过程化学倡议下的特殊项目化学办公室资助的项目。基本目标是了解血红素蛋白中电子传递的生物无机机制及其在细胞代谢微量金属中的作用。血红蛋白、肌红蛋白、细胞色素c和b5等血红素蛋白是铁（III）和铜（II）络合物的有效还原剂。电子可以通过外球电子转移机制从血红素Fe（II）转移到金属配合物上，距离可达20 A。本研究解决的问题是：1)什么动力学参数调节和控制电子转移？2)在血红素边缘的非特异性外球电子传递和金属配合物在电子转移之前的位点特异性结合中，是什么机制在起作用？3) Fe（III）和Cu（II）的低分子量配合物有哪些可能具有生化意义的理化特性？

This is a project supported by an award from the Chemistry Office of Special Projects under the aegis of the Chemistry of Life Processes Initiative. The fundamental goal is to understand the bioinorganic mechanisms for electron transport in heme proteins and their role in the metabolism of trace metals by cells. Several heme proteins including hemoglobin, myoglobin, cytochrome c and b5 are effective reductants for complexes of Fe(III) and Cu(II). Electrons can be transferred from the heme Fe(II) to the metal complex over distances as great as 20 A by an outer sphere electron transfer mechanism. The questions addressed in this research are: 1) What kinetic parameters regulate and control the electron transfer? 2) What mechanisms are operating in the non-specific outer sphere electron transport at the heme edge and in site-specific binding of the metal complex prior to electron transfer? 3) What are the physical-chemical characteristics of low molecular weight complexes of Fe(III) and Cu(II) that may be of biochemical significance?