Electron Transfer Reactions Between Cytochrome c, Cytochrome c Oxidase and Dioxygen

该项目得到了分析和表面化学计划的支持，为研究复杂介质中的膜结合酶开发了新的电化学方法。该项目由弗吉尼亚联邦大学的阿尔伯特·斯内登博士和他的团队领导，该项目准备并表征了细胞色素c氧化酶(CCO)的稳定组装，该组装吸附在固定在镀银金电极上的脂双层上。使用石英晶体微珠在电极上涂上一层最佳的银层。然后将十八烷基硫醇覆盖在电极上，形成双层的锚定。原子力显微镜用于确证膜的结构。电化学实验证实，这种双层膜模拟了CCO的体内反应活性。已知的氰化物和CCO之间的反应构成了这些研究的基础。在流动条件下还原的细胞色素、双层中的CCO和电极之间的电子转移反应是氰化物浓度、稳态周转率和氧气浓度的函数。这项研究为研究复杂介质中的膜结合酶开辟了新的电化学方法。这项研究的结果将有助于评估化合物作为酶抑制剂的潜在疗效，并将在药物测试等领域发挥重要作用。

This project, which is supported in the Analytical and Surface Chemistry program develops new electrochemical methods for studying membrane-bound enzymes in complex media. Conducted by Dr. Albert Sneden and his group at Virginia Commonwealth University, the project prepares and characterizes stable assemblies of cytochrome c oxidase (CCO) adsorbed on a lipid bilayer that is anchored into a silver-coated gold electrode. A quartz crystal microbabance is used to coat the electrode with an optimum layer of silver. The electrode is then covered with octadectyl mercaptan to form an anchor for the bilayer. Atomic Force Microscopy is used to confirm the structure of the membrane. Electrochemical experiments have confirmed that such a bilayer mimics the in vivo reactivities of CCO. The known reaction between cyanide and CCO forms the basis for these studies. The electron transfer reaction between reduced cytochrome under flow conditions, CCO in the bilayer, and the electrode is characterized as a function of cyanide concentration, steady state turnover rate, and oxygen concentration. This research develops new electrochemical methods for studying membrane-bound enzymes in complex media. Results from this research will be useful for assessing the potential efficacy of compounds as enzyme inhibitors and will be important in areas such as drug testing.