Chauvet, A.A.P., Al Haddad, A., Kao, W-C. et al. (3 more authors) (2014) Photo-induced dynamics of the heme centers in cytochrome bc 1. Physical Chemistry Chemical Physics, 17 (3). pp. 2143-2151. ISSN 1463-9076
Abstract
The ultrafast response of cytochrome bc1 is investigated for the first time, via transient absorption spectroscopy. The distinct redox potentials of both c1- and b-hemes allow for a clear differentiation of their respective signals. We find that while the c1-heme photo-product exhibits the characteristics of a 5-coordinated species, the b-hemes presumably undergo photo-oxidation at a remarkably high quantum yield. The c1-heme iron–ligand recombination time is 5.4 ps, in agreement with previous reports on homologous cytochromes. The suggested photo-oxidized state of the b-hemes has a lifetime of 6.8 ps. From this short life-time we infer that the electron acceptor must be within van der Walls contact with the heme, which points to the fact that the axial histidine residue is the electron acceptor. The different heme-responses illustrate the flexibility of the c1-heme ligation in contrast to the more rigid b-heme binding, as well as the higher electronic reactivity of the b-hemes within the bc1 complex. This study also demonstrates the remarkable connection between the heme local environment and its dynamics and, therefore, biological function
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 Royal Society of Chemistry. This is an author produced version of a paper subsequently published in Physical Chemistry Chemical Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Chemistry (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 08 Jun 2017 14:54 |
Last Modified: | 19 Jul 2017 08:10 |
Published Version: | http://doi.org/10.1039/C4CP04805A |
Status: | Published |
Publisher: | Royal Society of Chemistry |
Refereed: | Yes |
Identification Number: | 10.1039/C4CP04805A |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:108950 |