Proton-Coupled Electron Transfer in Cytochrome c Oxidase: Heme a Controls the Protonation Dynamics of E286.

ABSTRACT: Complex IV of the mitochondrial respiratory chain, or cytochrome c oxidase (CcO), contributes to the proton motive force necessary for ATP synthesis. CcO can slow the formation of reactive oxygen species and is key to physiology and drug development. The exact molecular mechanisms underlying its proton-pumping function remain elusive. The redox state of CcO's metallic cofactors is intimately connected to structural changes and proton pumping via proton-coupled electron transfer. Time-resolved UV/Vis and IR spectroscopy are used to investigate the effects of the electronic backreaction triggered by photolyzing the CO-inhibited 2-electron reduced state, R₂CO, in the aa₃ oxidase from Cereibacter sphaeroides. An intermediate is identified, in which the binuclear center ma

SUBMITTER: Baserga F 

PROVIDER: S-EPMC12710179 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature