Cytochrome c oxidase (EC 1.9.3.1) is the terminal enzyme of the mitochondria respiratory chain catalysing electron transfer from cytochrome c to molecular oxygen [ 1,2]. The molecular mechanism of this process is still not understood. At present, little is known about such important structural features as the position of the prosthetic groups or the location and characteristics of the cytochrom...

In the preceding paper the oxidation of substrates by “indophenol oxidase” was demonstrated to be a joint action of cytochrome and cytochrome oxidase. It was further shown that with a given amount of oxidase the velocity of hydroquinone oxidation reached a maximum as the amount of added cytochrome was increased. The latter fact immediately suggested the probability that the rapid aerobic oxidat...

The inhibition of cytochrome c oxidase by cyanide, starting either with the resting or the pulsed enzyme, was studied by rapid-freeze quenching followed by quantitative e.p.r. It is found that a partial reduction of cytochrome oxidase by transfer of 2 electron equivalents from ferrocytochrome c to cytochrome a and CuA will induce a transition from a closed to an open enzyme conformation, render...