细胞色素c氧化酶中一种新的铜（II）电子顺磁共振信号的特性

The identity of a new copper(II) electron paramagnetic resonance signal in cytochrome c oxidase.

作者信息

Karlsson B, Andréasson L E

出版信息

Biochim Biophys Acta. 1981 Mar 12;635(1):73-80. doi: 10.1016/0005-2728(81)90008-6.

Abstract

In reoxidation experiments with cytochrome c oxidase (EC 1.9.3.1) in the presence of both reducing substrate and molecular oxygen, a new EPR signal from Cu2+ has been observed. The new signal corresponds to 0.45 Cu per functional unit. It is concluded that the new EPR signal originates from CuB2+, the copper which is EPR-nondetectable in the resting enzyme. Optical absorption changes in the 500-700 nm region accompanies the decay of the new Cu2+ EPR signal. Based on the results in this investigation a catalytic cycle for cytochrome oxidase is proposed.

摘要

在存在还原底物和分子氧的情况下，对细胞色素c氧化酶（EC 1.9.3.1）进行再氧化实验时，观察到了来自Cu2+的新的电子顺磁共振（EPR）信号。新信号对应于每个功能单元0.45个铜原子。得出的结论是，新的EPR信号源自CuB2+，即静止酶中EPR无法检测到的铜。新的Cu2+ EPR信号衰减时，500 - 700 nm区域会出现光吸收变化。基于本研究结果，提出了细胞色素氧化酶的催化循环。