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Theoretical Investigations of Reaction Center Chromophores

  • Bruno Källebring
  • Örjan Hansson
  • Sven Larsson

Abstract

The primary electron donor (P or “special pair”) in the bacterial reaction center (RC) is a dimer of bacterio-chlorophyll (BCh1). The experimental spectrum of P is red-shifted compared to BCh1 in solution. This is due to interactions between the two BChls and to interactions between P and the surrounding protein. Explanations of the special properties of P have been offered by several investigators [1–8]. Recent hole-burning [9] and electric-field [10] studies suggest that the first excited state of P has charge-transfer character. In our earlier calculations [11], using preliminary coordinates where P was planar, we could not see any localization of the orbitals on to either BChl. With the refined coordinates P was found to be non-planar. We have now investigated the effects of this non-planarity, as well as those of the axial histidine ligands, on spectra, orbital distributions and transition-dipole orientations.

Keywords

Excited State Reaction Center Reference Direction Special Pair Primary Electron Donor 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media New York 1990

Authors and Affiliations

  • Bruno Källebring
    • 1
  • Örjan Hansson
    • 1
  • Sven Larsson
    • 2
  1. 1.Dept. of Biochemistry and BiophysicsUniv. of Göteborg and Chalmers Univ. of TechnologyGöteborgSweden
  2. 2.Dept. of Physical ChemistryUniv. of Göteborg and Chalmers Univ. of TechnologyGöteborgSweden

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