The vectorial nature of redox Bohr effects (redox-linked pK shifts) in cytochrome c oxidase from bovine heart incorporated in liposomes has been analyzed. The Bohr effects linked to oxide-reduction of heme a and CUB display membrane vectorial asymmetry. This provides evidence for involvement of redox Bohr effects in the proton pump of the oxidase.
Capitanio, N., Capitanio, G., De Nitto, E., & Papa, S. (1997). Vectorial nature of redox Bohr effects in bovine heart cytochrome c oxidase. FEBS Letters, 414(2), 414–418. https://doi.org/10.1016/S0014-5793(97)01043-0