Files
Document type
ArticleVersion
Accepted versionPublication date
All rights reserved
Please use this identifier to cite or link to this item: https://hdl.handle.net/2445/175421
Photosynthetic Light-Harvesting Is Tuned by the Heterogeneous Polarizable Environment of the Protein
Journal Title
Director/Tutor
Journal ISSN
Volume Title
Related resource
Abstract
In photosynthesis, special antenna proteins that contain multiple light-absorbing molecules (chromophores) are able to capture sunlight and transfer the excitation energy to reaction centers with almost 100% quantum efficiencies. The critical role of the protein scaffold in holding the appropriate arrangement of the chromophores is well established and can be intuitively understood given the need to keep optimal dipole−dipole interactions between the energy-transferring chromophores, as described by Förster theory more than 60 years ago. However, the question whether the protein structure can also play an active role by tuning such dipole−dipole interactions has not been answered so far, its effect being rather crudely described by simple screening factors related to the refractive index properties of the system. Here, we present a combined quantum chemical/molecular mechanical approach to compute electronic couplings that accounts for the heterogeneous dielectric nature of the protein−solvent environment in atomic detail. We apply the method to study the effect of dielectric heterogeneity in the energy migration properties of the PE545 principal light-harvesting antenna of the cryptomonad Rhodomonas CS24. We find that dielectric heterogeneity can profoundly tune by a factor up to 4 the energy migration rates between chromophore sites compared to the average continuum dielectric view that has historically been assumed. Our results indicate that engineering of the local dielectric environment can potentially be used to optimize artificial light-harvesting antenna systems.
Subject
Subject (English)
Citation
Citation
CURUTCHET BARAT, Carles E., et al. Photosynthetic Light-Harvesting Is Tuned by the Heterogeneous Polarizable Environment of the Protein. Journal of the American Chemical Society. 2011. Vol. 133, num. 9, pags. 3078-3084. ISSN 0002-7863. [consulted: 12 of June of 2026]. Available at: https://hdl.handle.net/2445/175421