固定在脂质双层膜内的细胞色素c氧化酶电化学研究

含有单体牛细胞色素c氧化酶的脂质双层膜，被成功地固定在金石英晶体微平衡电极上．在较宽的pH值、温度和缓冲浓度范围内观察到了氧化酶修饰电极上的直接电子迁移．氧化酶修饰电极在80℃以上时保持直接电子迁移性质。将电极冷却到室温时，氧化酶仍保持电子迁移能力．在22～80℃范围内。温度变化可引起细胞色素c氧化酶的相转移，估计出了相转移前后的相应反应活化能通过射流分析，研究了在溶液含有亚铁细胞色素c氧化酶的电氧化过程中。乙腈同细胞色素c氧化酶的结合．结果显示：浓度1．3M具有常数Ki时。细胞色素c氧化酶和乙腈形成配合物．每个细胞色素c氧化酶配一个乙腈分子。乙腈同细胞色素氧化酶的结合过程是可逆过程．

Electrochemical Study on Cytochrome C Oxidase Immobilized into Lipid Bilayer Membrane

Lipid bilayer membrane containing monomeric bovine cytochrome c oxidase was successfully immobilized in gold quartz crystal microbalance electrodes. Direct electron transfer on the oxidase modified electrode was observed over a wide range of pH, temperature and buffer concentration. The oxidase modified electrode maintains direct electron transfer properties at the temperature in excess of 80 ℃. Upon cooling down the electrode to room temperature, the oxidase still retained its electron transfer capabilities. Temperature can cause phase transition of cytochrome c oxidase in the temperature range of 22 to 80 ℃. The corresponding reaction activation energies before and after the transition were estimated.Acetonitrile binding to cytochrome c oxidase during the electroxidative process of solution-resident ferrocytochrome c was also investigated by flow injection analysis. The results showed that cytochrome c oxidase forms a complex with acetonitrile having a Ki of 1.3 M with a stoichiometry of 1 acetonitrile molecule per cytochrome c oxidase. The binding of acetonitrile to cytochrome oxidase is a reversible process.