 Ten specific binding sites for ADP or ATP were identified in mammalian cytochrome c oxidase, which regulate the H+/e- stoichiometry of proton pumping, and the allosteric inhibition of activity, depending on the ATP/ADP ratio.Stress-dependent reversible dephosphorylation of cytochrome c oxidase suggests formation of reactive oxygen species.A hypothesis on the cause of oxidative stress, aging and disease was published by Kadenbach in 2013.