title: Modeling of various optical spectra in the presence of slow excitation energy transfer in dimers and trimers with weak interpigment coupling: FMO as an example.
abstract: We present an improved simulation methodology to describe nonphotochemical hole-burned (NPHB) spectra. The model, which includes both frequency-dependent excitation energy transfer (EET) rate distributions and burning following EET, provides reasonable fits of various optical spectra including resonant and nonresonant holes in the case of FMO complex. A qualitative description of the NPHB process in light of a very complex protein energy landscape is briefly discussed. As an example, we show that both resonant and nonresonant HB spectra obtained for the 825 nm band of the trimeric FMO of C. tepidum are consistent with the presence of a relatively slow EET between the lowest energy states of the monomers of the trimer (mostly localized on BChl a 3), with a weak (∼1 cm(-1)) coupling between these states revealed via calculated emission spectra. We argue that the nature of the so-called 825 nm absorption band of the FMO trimer, contrary to the presently accepted consensus, cannot be explained by a single transition.
authors: Department of Physics, Concordia University , Montreal, H4B 1R6 Quebec, Canada.
authors: Nicoleta
authors: N
authors: Herascu
authors: Adam
authors: A
authors: Kell
authors: Khem
authors: K
authors: Acharya
authors: Ryszard
authors: R
authors: Jankowiak
authors: Robert E
authors: RE
authors: Blankenship
authors: Valter
authors: V
authors: Zazubovich
mesh_terms: D000042:Absorption; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D004735:Energy Transfer; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D055620:Optical Phenomena; D010860:Pigments, Biological / Q000378:metabolism; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D013057:Spectrum Analysis
chemical_list: D001426:Bacterial Proteins; C086320:FMO bacteriochlorophyll protein, Bacteria; D045342:Light-Harvesting Protein Complexes; D010860:Pigments, Biological