Effective pumping proton collection facilitated by a copper site (CuB) of bovine heart cytochrome c oxidase, revealed by a newly developed time-resolved infrared system.

ABSTRACT: X-ray structural and mutational analyses have shown that bovine heart cytochrome c oxidase (CcO) pumps protons electrostatically through a hydrogen bond network using net positive charges created upon oxidation of a heme iron (located near the hydrogen bond network) for O2 reduction. Pumping protons are transferred by mobile water molecules from the negative side of the mitochondrial inner membrane through a water channel into the hydrogen bond network. For blockage of spontaneous proton back-leak, the water channel is closed upon O2 binding to the second heme (heme a3) after complete collection of the pumping protons in the hydrogen bond network. For elucidation of the structural bases for the mechanism of the proton collection and timely closure of the water channel, conformational dynam

SUBMITTER: Kubo M 

PROVIDER: S-EPMC3798492 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature