Primary Intermediates in the Reaction of Cytochrome c over - Oxidase with Oxygen
The primary intermediates in the reaction of oxygen with fully reduced and mixed valence cytochrome c oxidase were generated in a rapid mixing continuous flow apparatus. In the primary intermediate of both forms of the enzyme the Fe-O sub 2 stretching mode is located at 568 cm sup (-1) and its assignment was confirmed by oxygen isotope studies. These data demonstrate that: 1. The primary intermediate in the reaction of oxygen with fully reduced cytochrome c oxidase may be generated at room temperature; 2. The oxidation state of cytochrome a plays no role in the structure of the oxygen binding site; 3. The initial Fe-O sub 2 bonding does not have any unique structural features which could lead to the rapid reduction of dioxygen to water.