Long-Distance Charge Transport between Cytochrome c and Complex III is Mediated by Protons and Reactive Oxygen Species
Electron transfer (ET) between redox proteins is an essential process in the respiratory and photosynthetic transport chains. While intra-protein ET is well characterized, the experimental methods to investigate inter-protein ET are limited by the presence of the solvent and by the transient nature...
| Autores: | , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/415962 |
| Acceso en línea: | http://hdl.handle.net/10261/415962 https://api.elsevier.com/content/abstract/scopus_id/105015835217 |
| Access Level: | acceso abierto |
| Palabra clave: | Gouy‐Chapman conduit Grotthuss (Grothuss) proton hopping conduction Electrochemical STM Kinetic isotope effect KIE Mitochondria Proton coupled electron transfer PCET Reactive oxygen species ROS Superoxide radical anion SOX |
| Sumario: | Electron transfer (ET) between redox proteins is an essential process in the respiratory and photosynthetic transport chains. While intra-protein ET is well characterized, the experimental methods to investigate inter-protein ET are limited by the presence of the solvent and by the transient nature of the protein-protein interaction and ET event, which are averaged in protein ensembles. Wiring precisely oriented redox protein partners to the nanoscale electrodes of an electrochemical scanning tunneling microscope allows recording the time- and distance-dependence of the current flowing between them. These methods have revealed that the current flowing between individual protein pairs extends beyond tunneling distances and that it is electrochemically gated. However, the corresponding mechanism and the identity of the charge carriers in aqueous solution remain to be elucidated. To determine the species involved in long-distance charge transport between the redox partner proteins Cc and Cc1 of the respiratory chain, recordings are performed as a function of pH, in heavy water solutions, and in degassed solutions. It is observed that the spatial span and electrochemical gating of long-distance currents are reduced at high pH, in heavy water, and at low oxygen concentration, showing that the currents are assisted by superoxide anions and by protons. |
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