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Nikolaev DM, Manathunga M, Orozco-Gonzalez Y, Shtyrov AA, Guerrero Martínez YO, Gozem S, Ryazantsev MN, Coutinho K, Canuto S, Olivucci M. Free Energy Computation for an Isomerizing Chromophore in a Molecular Cavity via the Average Solvent Electrostatic Configuration Model: Applications in Rhodopsin and Rhodopsin-Mimicking Systems. J Chem Theory Comput 2021; 17:5885-5895. [PMID: 34379429 DOI: 10.1021/acs.jctc.1c00221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a novel technique for computing the free energy differences between two chromophore "isomers" hosted in a molecular environment (a generalized solvent). Such an environment may range from a relatively rigid protein cavity to a flexible solvent environment. The technique is characterized by the application of the previously reported "average electrostatic solvent configuration" method, and it is based on the idea of using the free energy perturbation theory along with a chromophore annihilation procedure in thermodynamic cycle calculations. The method is benchmarked by computing the ground-state room-temperature relative stabilities between (i) the cis and trans isomers of prototypal animal and microbial rhodopsins and (ii) the analogue isomers of a rhodopsin-like light-driven molecular switch in methanol. Furthermore, we show that the same technology can be used to estimate the activation free energy for the thermal isomerization of systems i-ii by replacing one isomer with a transition state. The results show that the computed relative stability and isomerization barrier magnitudes for the selected systems are in line with the available experimental observation in spite of their widely diverse complexity.
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Affiliation(s)
- Dmitrii M Nikolaev
- Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, 8/3 Khlopina Street, St. Petersburg 194021, Russia
| | - Madushanka Manathunga
- Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - Yoelvis Orozco-Gonzalez
- Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403, United States.,Department of Chemistry, Georgia State University, Atlanta, Georgia 30303, United States
| | - Andrey A Shtyrov
- Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, 8/3 Khlopina Street, St. Petersburg 194021, Russia
| | | | - Samer Gozem
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30303, United States
| | - Mikhail N Ryazantsev
- Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia.,Institute of Biomedical Systems and Biotechnologies, Peter the Great St. Petersburg Polytechnic University, St. Petersburg 195251, Russia
| | - Kaline Coutinho
- Instituto de Física, Universidade de São Paulo, Cidade Universitária, São Paulo 05508-090, Brazil
| | - Sylvio Canuto
- Instituto de Física, Universidade de São Paulo, Cidade Universitária, São Paulo 05508-090, Brazil
| | - Massimo Olivucci
- Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403, United States.,Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, via A. Moro 2, I-53100 Siena, Italy.,Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg-CNRS, UMR 7504, F-67034 Strasbourg, France
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Pugh EN. The mechanism of photon-like dark noise in rod photoreceptors. J Gen Physiol 2019; 151:875-877. [PMID: 31171571 PMCID: PMC6605688 DOI: 10.1085/jgp.201912376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Pugh highlights recent work ruling out a role for ultraweak photon emission in spontaneous photon-like events in retinal rods.
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Affiliation(s)
- Edward N Pugh
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA
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