Theoretical examination of quantum coherence in a photosynthetic system at physiological temperature.
The observation of long-lived electronic coherence in a photosynthetic pigment-protein complex, the Fenna-Matthews-Olson (FMO) complex, is suggestive that quantum coherence might play a significant role in achieving the remarkable efficiency of photosynthetic electronic energy transfer (EET), although the data were acquired at cryogenic temperature [Engel GS, et al. (2007) Evidence for wavelike energy transfer through quantum coherence in photosynthetic systems. Nature 446:782-786]. In this paper, the spatial and temporal dynamics of EET through the FMO complex at physiological temperature are investigated theoretically. The numerical results reveal that quantum wave-like motion persists for several hundred femtoseconds even at physiological temperature, and suggest that the FMO complex may work as a rectifier for unidirectional energy flow from the peripheral light-harvesting antenna to the reaction center complex by taking advantage of quantum coherence and the energy landscape of pigments tuned by the protein scaffold. A potential role of quantum coherence is to overcome local energetic traps and aid efficient trapping of electronic energy by the pigments facing the reaction center complex.
Ishizaki
Akihito
A
Department of Chemistry, University of California, Berkeley, CA 94720, USA.
Fleming
Graham R
GR
D005075:Biological Evolution; D019414:Chlorobi / Q000502:physiology; D004581:Electronics; D004735:Energy Transfer / Q000502:physiology; D008954:Models, Biological; D010788:Photosynthesis / Q000502:physiology*; D011789:Quantum Theory; D012242:Rhodobacter sphaeroides / Q000502:physiology; D013696:Temperature