Proton translocation in cytochrome c oxidase: insights from proton exchange kinetics and vibrational spectroscopy.

ABSTRACT: Cytochrome c oxidase is the terminal enzyme in the electron transfer chain. It reduces oxygen to water and harnesses the released energy to translocate protons across the inner mitochondrial membrane. The mechanism by which the oxygen chemistry is coupled to proton translocation is not yet resolved owing to the difficulty of monitoring dynamic proton transfer events. Here we summarize several postulated mechanisms for proton translocation, which have been supported by a variety of vibrational spectroscopic studies. We recently proposed a proton translocation model involving proton accessibility to the regions near the propionate groups of the heme a and heme a3 redox centers of the enzyme based by hydrogen/deuterium (H/D) exchange Raman scattering studies (Egawa et al., PLoS ONE 2013). To

SUBMITTER: Ishigami I 

PROVIDER: S-EPMC4254173 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature