Proton-coupled electron transfer and the role of water molecules in proton pumping by cytochrome c oxidase.

ABSTRACT: Molecular oxygen acts as the terminal electron sink in the respiratory chains of aerobic organisms. Cytochrome c oxidase in the inner membrane of mitochondria and the plasma membrane of bacteria catalyzes the reduction of oxygen to water, and couples the free energy of the reaction to proton pumping across the membrane. The proton-pumping activity contributes to the proton electrochemical gradient, which drives the synthesis of ATP. Based on kinetic experiments on the O-O bond splitting transition of the catalytic cycle (A → P(R)), it has been proposed that the electron transfer to the binuclear iron-copper center of O2 reduction initiates the proton pump mechanism. This key electron transfer event is coupled to an internal proton transfer from a conserved glutamic acid to the proton-loadi

SUBMITTER: Sharma V 

PROVIDER: S-EPMC4343153 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature