title: Ultrafast absorption difference spectra of the Fenna-Matthews-Olson protein at 19 K: experiment and simulations.
abstract: We describe simulations of absorption difference spectra in strongly coupled photosynthetic antennas. In the presence of large resonance couplings, distinctive features arise from excited-state absorption transitions between one- and two-exciton levels. We first outline the theory for the heterodimer and for the general N-pigment system, and we demonstrate the transition between the strong and weak coupling regimes. The theory is applied to Fenna-Matthews-Olson (FMO) bacteriochlorophyll a protein trimers from the green photosynthetic bacterium Prosthecochloris aestuarii and then compared with experimental low-temperature absorption difference spectra of FMO trimers from the green bacterium Chlorobium tepidum.
authors.affiliation: Ames Laboratory-USDOE, Iowa, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Buck
authors.forename: S
authors.initials: S
authors.lastname: Savikhin
authors.forename: W S
authors.initials: WS
authors.lastname: Struve
mesh_terms: D001426:Bacterial Proteins; D019414:Chlorobi / Q000378:metabolism; D003198:Computer Simulation; D007700:Kinetics; D045342:Light-Harvesting Protein Complexes; D008433:Mathematics; D008962:Models, Theoretical; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D013055:Spectrophotometry, Infrared; D013816:Thermodynamics
chemical_list: D001426:Bacterial Proteins; C086320:FMO bacteriochlorophyll protein, Bacteria; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins