Calculation of pigment transition energies in the FMO protein: From simplicity to complexity and back

Julia Adolphs, Frank Müh, Mohamed Madjet, Thomas Renger

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121 Citations (Scopus)


The Fenna-Matthews-Olson (FMO) protein of green sulfur bacteria represents an important model protein for the study of elementary pigment-protein couplings. We have previously used a simple approach [Adolphs and Renger (2006) Biophys J 91:2778-2797] to study the shift in local transition energies (site energies) of the FMO protein of Prosthecochloris aestuarii by charged amino acid residues, assuming a standard protonation pattern of the titratable groups. Recently, we have found strong evidence that besides the charged amino acids also the neutral charge density of the protein is important, by applying a combined quantum chemical/electrostatic approach [Müh et al. (2007) Proc Natl Acad Sci USA, in press]. Here, we extract the essential parts from this sophisticated method to obtain a relatively simple method again. It is shown that the main contribution to the site energy shifts is due to charge density coupling (CDC) between the pigments and their pigment, protein and water surroundings and that polarization effects for qualitative considerations can be approximated by screening the Coulomb coupling by an effective dielectric constant.

Original languageEnglish
Pages (from-to)197-209
Number of pages13
JournalPhotosynthesis Research
Issue number2-3
Publication statusPublished - 1 Feb 2008
Externally publishedYes



  • Excitonic coupling
  • FMO protein
  • Genetic algorithm
  • Pigment-protein complex
  • Prosthecochloris aestuarii
  • Site energies

ASJC Scopus subject areas

  • Plant Science

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