还原型细胞色素氧化酶与氧气反应的停流研究。

A stopped-flow study of the reaction of reduced cytochrome oxidase with oxygen.

作者信息

Balny C, Anni H, Yonetani T

出版信息

J Inorg Biochem. 1985 Mar-Apr;23(3-4):253-8. doi: 10.1016/0162-0134(85)85032-7.

Abstract

The reaction of a reduced cytochrome oxidase system consisting of beef heart cytochrome oxidase, cytochrome c, and ascorbate with molecular oxygen was kinetically and thermodynamically investigated using a stopped-flow, rapid wavelength-scanning technique. Processes for oxidation of ferrocytochrome a, bound ferrocytochrome c, and free ferrocytochrome c have been identified, and their rate constants have been determined. Values of the activation energy for these reactions indicate that the oxidation of bound ferrocytochrome c is a simple chemical electron-transfer process and that oxidations of ferrocytochrome a and free ferrocytochrome c are complex processes involving changes in protein conformation.

摘要

利用停流快速波长扫描技术，对由牛心细胞色素氧化酶、细胞色素c和抗坏血酸组成的还原型细胞色素氧化酶系统与分子氧的反应进行了动力学和热力学研究。已确定了亚铁细胞色素a、结合态亚铁细胞色素c和游离亚铁细胞色素c的氧化过程，并测定了它们的速率常数。这些反应的活化能值表明，结合态亚铁细胞色素c的氧化是一个简单的化学电子转移过程，而亚铁细胞色素a和游离亚铁细胞色素c的氧化是涉及蛋白质构象变化的复杂过程。