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The simulation of interquinone charge transfer in a bacterial photoreaction center highlights the central role of a hydrogen-bonded non-heme iron complex.
- Source :
-
Biochimica et biophysica acta [Biochim Biophys Acta] 2011 Jan; Vol. 1807 (1), pp. 53-8. Date of Electronic Publication: 2010 Aug 13. - Publication Year :
- 2011
-
Abstract
- We consider electron transfer between the quinones Q(A) and Q(B), one of the final steps in the photoinduced charge separation in the photoreaction center of Rhodobacter sphaeroides. The system is described by a model with atomic resolution using classical force fields and a carefully parameterized tight-binding Hamiltonian. The rates estimated for direct interquinone charge transfer hopping involving a non-heme iron complex bridging the quinones and superexchange based on the geometry of the photochemically inactive dark state are orders of magnitude smaller than those obtained experimentally. Only if the iron complex is attached to both quinones via hydrogen bonds - as characteristic of the charge transfer active light state - the computed rate for superexchange involving the histidine ligands of the complex will become comparable to the experimental value of k(CT)=10⁵s⁻¹.<br /> (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Subjects :
- Computer Simulation
DNA, Bacterial metabolism
Hydrogen Bonding
Models, Molecular
Molecular Conformation
Photosynthetic Reaction Center Complex Proteins chemistry
Iron metabolism
Photosynthetic Reaction Center Complex Proteins metabolism
Quinones metabolism
Rhodobacter sphaeroides metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0006-3002
- Volume :
- 1807
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Biochimica et biophysica acta
- Publication Type :
- Academic Journal
- Accession number :
- 20709018
- Full Text :
- https://doi.org/10.1016/j.bbabio.2010.08.001