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Understanding the Relation between Structural and Spectral Properties of Light-Harvesting Complex II
- Source :
- Journal of Physical Chemistry A, 125(20), 4313-4322. American Chemical Society, The Journal of Physical Chemistry. a, Sen, S, Mascoli, V, Liguori, N, Croce, R & Visscher, L 2021, ' Understanding the Relation between Structural and Spectral Properties of Light-Harvesting Complex II ', Journal of Physical Chemistry A, vol. 125, no. 20, pp. 4313-4322 . https://doi.org/10.1021/acs.jpca.1c01467
- Publication Year :
- 2021
-
Abstract
- Light-harvesting complex II (LHCII) is a pigment-protein complex present in higher plants and green algae. LHCII represents the main site of light absorption, and its role is to transfer the excitation energy toward the photosynthetic reaction centers, where primary energy conversion reactions take place. The optical properties of LHCII are known to depend on protein conformation. However, the relation between the structural and spectroscopic properties of the pigments is not fully understood yet. In this respect, previous classical molecular dynamics simulations of LHCII in a model membrane [Sci. Rep. 2015, 5, 1-10] have shown that the configuration and excitonic coupling of a chlorophyll (Chl) dimer functioning as the main terminal emitter of the complex are particularly sensitive to conformational changes. Here, we use quantum chemistry calculations to investigate in greater detail the effect of pigment-pigment interactions on the excited-state landscape. While most previous studies have used a local picture in which electrons are localized on single pigments, here we achieve a more accurate description of the Chl dimer by adopting a supramolecular picture where time-dependent density functional theory is applied to the whole system at once. Our results show that specific dimer configurations characterized by shorter inter-pigment distances can result in a sizable intensity decrease (up to 36%) of the Chl absorption bands in the visible spectral region. Such a decrease can be predicted only when accounting for Chl-Chl charge-transfer excitations, which is possible using the above-mentioned supramolecular approach. The charge-transfer character of the excitations is quantified by two types of analyses: one focusing on the composition of the excitations and the other directly on the observable total absorption intensities.
- Subjects :
- Photosynthetic reaction centre
Chlorophyll
Light
Dimer
Supramolecular chemistry
Light-Harvesting Protein Complexes
Electron
010402 general chemistry
01 natural sciences
Quantum chemistry
Article
chemistry.chemical_compound
Molecular dynamics
0103 physical sciences
SDG 7 - Affordable and Clean Energy
Physical and Theoretical Chemistry
Absorption (electromagnetic radiation)
Density Functional Theory
010304 chemical physics
0104 chemical sciences
chemistry
Models, Chemical
Chemical physics
Spectrophotometry
Density functional theory
Subjects
Details
- Language :
- English
- ISSN :
- 10895639
- Database :
- OpenAIRE
- Journal :
- Journal of Physical Chemistry A, 125(20), 4313-4322. American Chemical Society, The Journal of Physical Chemistry. a, Sen, S, Mascoli, V, Liguori, N, Croce, R & Visscher, L 2021, ' Understanding the Relation between Structural and Spectral Properties of Light-Harvesting Complex II ', Journal of Physical Chemistry A, vol. 125, no. 20, pp. 4313-4322 . https://doi.org/10.1021/acs.jpca.1c01467
- Accession number :
- edsair.doi.dedup.....5dfa9568ae90cb52e62f1fa490bedca4