Excitonic Energy Landscape of the Y16F Mutant of the Chlorobium tepidum Fenna–Matthews–Olson (FMO) Complex: High Resolution Spectroscopic and Modeling Studies
- Kansas State Univ., Manhattan, KS (United States). Dept. of Chemistry
- Washington Univ., St. Louis, MO (United States). Dept. of Biology and Chemistry
- Kansas State Univ., Manhattan, KS (United States). Dept. of Chemistry, and Dept. of Physics
We report high-resolution (low-temperature) absorption, emission, and nonresonant/resonant hole-burned (HB) spectra and results of excitonic calculations using a non-Markovian reduced density matrix theory (with an improved algorithm for parameter optimization in heterogeneous samples) obtained for the Y16F mutant of the Fenna–Matthews–Olson (FMO) trimer from the green sulfur bacterium Chlorobium tepidum. We show that the Y16F mutant is a mixture of FMO complexes with three independent low-energy traps (located near 817, 821, and 826 nm), in agreement with measured composite emission and HB spectra. Two of these traps belong to mutated FMO subpopulations characterized by significantly modified low-energy excitonic states. Hamiltonians for the two major subpopulations (Sub821 and Sub817) provide new insight into extensive changes induced by the single-point mutation in the vicinity of BChl 3 (where tyrosine Y16 was replaced with phenylalanine F16). The average decay time(s) from the higher exciton state(s) in the Y16F mutant depends on frequency and occurs on a picosecond time scale.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Photosynthetic Antenna Research Center (PARC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0001035
- OSTI ID:
- 1470597
- Journal Information:
- Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry, Vol. 122, Issue 14; Related Information: PARC partners with Washington University in St. Louis (lead); University of California, Riverside; University of Glasgow, UK; Los Alamos National Laboratory; University of New Mexico; New Mexico Corsortium; North Carolina State University; Northwestern University; Oak Ridge National Laboratory; University of Pennsylvania; Sandia National Laboratories; University of Sheffield, UK; ISSN 1520-6106
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Stereoselective self-aggregation of synthetic zinc 3 1 -epimeric bacteriochlorophyll- d analogs possessing a methylene group at the 13 2 -position as models of green photosynthetic bacterial chlorosomes
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journal | January 2019 |
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