The effect of pH on the near-uv absorption spectrum of cytochrome oxidase has been examined. Several lines of evidence are consistent with a proton binding site that can modulate the optical properties of cytochrome a^. ...

Previous studies of hydrogen peroxide interaction with oxidized cytochrome oxidase showed a lack of uniformity and consistency. Problems arose from the use of heterogeneous enzyme (isolated at pH 7.0-7.4) and a large excess ...