Ashe, D and Alleyne, T and Wilson, MT and Svistunenko, DA and Nicholls, P (2014) Redox equilibration after one-electron reduction of cytochrome c oxidase: Radical formation and a possible hydrogen relay mechanism. Archives of Biochemistry and Biophysics, 554. pp. 36-43. DOI https://doi.org/10.1016/j.abb.2014.04.015
Ashe, D and Alleyne, T and Wilson, MT and Svistunenko, DA and Nicholls, P (2014) Redox equilibration after one-electron reduction of cytochrome c oxidase: Radical formation and a possible hydrogen relay mechanism. Archives of Biochemistry and Biophysics, 554. pp. 36-43. DOI https://doi.org/10.1016/j.abb.2014.04.015
Ashe, D and Alleyne, T and Wilson, MT and Svistunenko, DA and Nicholls, P (2014) Redox equilibration after one-electron reduction of cytochrome c oxidase: Radical formation and a possible hydrogen relay mechanism. Archives of Biochemistry and Biophysics, 554. pp. 36-43. DOI https://doi.org/10.1016/j.abb.2014.04.015
Abstract
Kinetic studies using UV/visible and EPR spectroscopy were carried out to follow the distribution of electrons within beef heart cytochrome c oxidase (CcO), both active and cyanide-inhibited, following addition of reduced cytochrome c as electron donor. In the initial one-electron reduced state the electron is shared between three redox centers, heme a, CuA and a third site, probably CuB. Using a rapid freeze system and the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) a protein radical was also detected. The EPR spectrum of the DMPO adduct of this radical was consistent with tyrosyl radical capture. This may be a feature of a charge relay mechanism involved in some part of the CcO electron transfer system from bound cytochrome c via CuA and heme a to the a3CuB binuclear center.
Item Type: | Article |
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Uncontrolled Keywords: | Tryptophan; Tyrosine; Cytochrome c oxidase; Electron transfer; Amino acid radical; DMPO; Cyanide; Spin trap |
Subjects: | Q Science > QH Natural history > QH301 Biology |
Divisions: | Faculty of Science and Health Faculty of Science and Health > Life Sciences, School of |
SWORD Depositor: | Unnamed user with email elements@essex.ac.uk |
Depositing User: | Unnamed user with email elements@essex.ac.uk |
Date Deposited: | 03 Jul 2015 06:31 |
Last Modified: | 24 May 2024 12:07 |
URI: | http://repository.essex.ac.uk/id/eprint/14174 |