Simulated two-dimensional electronic spectroscopy of the eight-bacteriochlorophyll FMO complex

Journal Article · Sun Dec 21 04:00:00 EST 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4903546· OSTI ID:22413323

Yeh, Shu-Hao ^[1]; Kais, Sabre ^[1]

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1. Department of Chemistry and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)

The Fenna-Matthews-Olson (FMO) protein-pigment complex acts as a molecular wire conducting energy between the outer antenna system and the reaction center; it is an important photosynthetic system to study the transfer of excitonic energy. Recent crystallographic studies report the existence of an additional (eighth) bacteriochlorophyll a (BChl a) in some of the FMO monomers. To understand the functionality of this eighth BChl, we simulated the two-dimensional electronic spectra of both the 7-site (apo form) and the 8-site (holo form) variant of the FMO complex from green sulfur bacteria, Prosthecochloris aestuarii. By comparing the spectrum, it was found that the eighth BChl can affect two different excitonic energy transfer pathways: (1) it is directly involved in the first apo form pathway (6 → 3 → 1) by passing the excitonic energy to exciton 6; and (2) it facilitates an increase in the excitonic wave function overlap between excitons 4 and 5 in the second pathway (7 → 4,5 → 2 → 1) and thus increases the possible downward sampling routes across the BChls.

• OSTI ID: 22413323
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 23 Vol. 141; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ANTENNAS
BACTERIA
CRYSTALLOGRAPHY
ENERGY TRANSFER
EXCITONS
MONOMERS
PROTEINS
SIMULATION
SPECTRA
SPECTROSCOPY
SULFUR
TWO-DIMENSIONAL CALCULATIONS
TWO-DIMENSIONAL SYSTEMS
WAVE FUNCTIONS