Reversible Switching of Redox-Active Molecular Orbitals and Electron Transfer Pathways in Cu<inf>A</inf> Sites of Cytochrome c Oxidase
The Cu<inf>A</inf> site of cytochromec oxidase is a redox hub that participates in rapid electron transfer at low driving forces with two redox cofactors in nearly perpendicular orientations. Spectroscopic and electrochemical characterizations performed on first and second-sphere mutants...
Guardado en:
| Autores principales: | , , , , , |
|---|---|
| Formato: | JOUR |
| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_14337851_v54_n33_p9555_Zitare |
| Aporte de: |
| Sumario: | The Cu<inf>A</inf> site of cytochromec oxidase is a redox hub that participates in rapid electron transfer at low driving forces with two redox cofactors in nearly perpendicular orientations. Spectroscopic and electrochemical characterizations performed on first and second-sphere mutants have allowed us to experimentally detect the reversible switching between two alternative electronic states that confer different directionalities to the redox reaction. Specifically, the M160H variant of a native Cu<inf>A</inf> shows a reversible pH transition that allows to functionally probe both states in the same protein species. Alternation between states exerts a dramatic impact on the kinetic redox parameters, thereby suggesting this effect as the mechanism underlying the efficiency and directionality of Cu<inf>A</inf> electron transfer invivo. These findings may also prove useful for the development of molecular electronics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
|---|