Probing the Role of the Eighth Bacteriochlorophyll in holo-FMO Complex by Simulated Two-Dimensional Electronic Spectroscopy

Abstract

The Fenna-Matthews-Olson (FMO) protein-pigment complex acts as a molecular wire between the outer antenna system and the reaction center (RC); it is an important model system to study the excitonic energy transfer. Recent crystallographic studies report the existence of an additional (eighth) bacteriochlorophyll a (BChl a). 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 difference between the spectrum, it was found that the eighth BChl can affect two different excitonic energy transfer pathways, these being: (1) directly involve in the first pathway 6 $\to$ 3 $\to$ 1 of the apo form model by passing the excitonic energy to exciton 6; and (2) increase the excitonic wave function overlap between excitons 4 and 5 in the second pathway (7 $\to$ 4,5 $\to$ 2 $\to$ 1) and thus increase the possible downward sampling routes across the BChls.

20 pages, 9 figures, 2 tables

References in corpus (5)

• Environment-Assisted Quantum Walks in Photosynthetic Energy Transfer
• Environment-Assisted Quantum Transport
• Modified-scaled hierarchical equation of motion approach for the study of quantum coherence in photosynthetic complexes
• Exciton coupling induces vibronic hyperchromism in light-harvesting complexes
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Cited by in corpus (3)

• Proposal for probing energy transfer pathway by single-molecule pump-dump experiment
• Non-markovian neural quantum propagator and its application to the simulation of ultrafast nonlinear spectra
• Quantum simulation of FMO complex using one-parameter semigroup of generators