Electrostatic basis for the unidirectionality of the primary proton transfer in cytochrome c oxidase.

ABSTRACT: Gaining detailed understanding of the energetics of the proton-pumping process in cytochrome c oxidase (CcO) is one of the challenges of modern biophysics. Despite promising mechanistic proposals, most works have not related the activation barriers of the different assumed steps to the protein structure, and there has not been a physically consistent model that reproduced the barriers needed to create a working pump. This work reevaluates the activation barriers for the primary proton transfer (PT) steps by calculations that reflect all relevant free energy contributions, including the electrostatic energies of the generated charges, the energies of water insertion, and large structural rearrangements of the donor and acceptor. The calculations have reproduced barriers that account for the

SUBMITTER: Pisliakov AV 

PROVIDER: S-EPMC2409407 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature