Quantum-classical simulations of rhodopsin reveal excited-state population splitting and its effects on quantum efficiency.

Autor: Yang X; Department of Chemistry, Bowling Green State University, Bowling Green, OH, USA., Manathunga M; Department of Chemistry, Bowling Green State University, Bowling Green, OH, USA., Gozem S; Department of Chemistry, Georgia State University, Atlanta, GA, USA., Léonard J; Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS, Strasbourg, France., Andruniów T; Department of Chemistry, Wroclaw University of Science and Technology, Wroclaw, Poland., Olivucci M; Department of Chemistry, Bowling Green State University, Bowling Green, OH, USA. molivuc@bgsu.edu.; Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, Siena, Italy. molivuc@bgsu.edu.; Institute for Advanced Studies, University of Strasbourg, Strasbourg, France. molivuc@bgsu.edu.
Jazyk: angličtina
Zdroj: Nature chemistry [Nat Chem] 2022 Apr; Vol. 14 (4), pp. 441-449. Date of Electronic Publication: 2022 Mar 03.
DOI: 10.1038/s41557-022-00892-6
Abstrakt: The activation of rhodopsin, the light-sensitive G-protein-coupled receptor responsible for dim-light vision in vertebrates, is driven by an ultrafast excited-state double-bond isomerization with a quantum efficiency of almost 70%. The origin of such light sensitivity is not understood and a key question is whether in-phase nuclear motion controls the quantum efficiency value. In this study we used hundreds of quantum-classical trajectories to show that, 15 fs after light absorption, a degeneracy between the reactive excited state and a neighbouring state causes the splitting of the rhodopsin population into subpopulations. These subpopulations propagate with different velocities and lead to distinct contributions to the quantum efficiency. We also show here that such splitting is modulated by protein electrostatics, thus linking amino acid sequence variations to quantum efficiency modulation. Finally, we discuss how such a linkage that in principle could be exploited to achieve higher quantum efficiencies would simultaneously increase the receptor thermal noise leading to a trade-off that may have played a role in rhodopsin evolution.
(© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)
Databáze: MEDLINE
Externí odkaz: