1
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Matveeva R, Folkestad SD, Høyvik IM. Particle-Breaking Hartree-Fock Theory for Open Molecular Systems. J Phys Chem A 2023; 127:1329-1341. [PMID: 36720055 PMCID: PMC9923758 DOI: 10.1021/acs.jpca.2c07686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In this work we present the particle-breaking Hartree-Fock (PBHF) model which is a mean-field approach to open molecular systems. The interaction of a system with the environment is parametrized through a particle-breaking term in the molecular Hamiltonian. The PBHF wave function is constructed through an exponential unitary transformation of a Slater determinant with a given number of electrons. We consider only the closed-shell formalism. The parametrization results in a linear combination of Slater determinants with different numbers of electrons, i.e., the PBHF wave function is not an eigenfunction of the number operator. As a result, the density matrix may have fractional occupations which are, because of the unitary parametrization, always between 0.0 and 2.0. The occupations are optimized simultaneously with the orbitals, using the trust-region optimization procedure. In the limit of a particle-conserving Hamiltonian, the PBHF optimization will converge to a standard Hartree-Fock wave function. We show that the average number of electrons may be decreased or increased depending on whether the particle-breaking term affects occupied or virtual orbitals.
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2
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Chang C, Kuramochi H, Singh M, Abe‐Yoshizumi R, Tsukuda T, Kandori H, Tahara T. A Unified View on Varied Ultrafast Dynamics of the Primary Process in Microbial Rhodopsins. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202111930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Chun‐Fu Chang
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako Saitama 351-0198 Japan
- Department of Chemistry Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo-Ku Tokyo 113-0033 Japan
| | - Hikaru Kuramochi
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako Saitama 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP), RIKEN 2-1 Hirosawa Wako Saitama 351-0198 Japan
- PRESTO (Japan) Science and Technology Agency 4-1-8 Honcho Kawaguchi Saitama 332-0012 Japan
- Present address: Research Center of Integrative Molecular Systems Institute for Molecular Science 38 Nishigo-Naka Myodaiji Okazaki 444-8585 Japan
| | - Manish Singh
- Department of Life Science and Applied Chemistry Nagoya Institute of Technology, Showa-Ku Nagoya Aichi 466-8555 Japan
| | - Rei Abe‐Yoshizumi
- Department of Life Science and Applied Chemistry Nagoya Institute of Technology, Showa-Ku Nagoya Aichi 466-8555 Japan
| | - Tatsuya Tsukuda
- Department of Chemistry Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo-Ku Tokyo 113-0033 Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry Nagoya Institute of Technology, Showa-Ku Nagoya Aichi 466-8555 Japan
- OptoBioTechnology Research Center Nagoya Institute of Technology Showa-Ku, Nagoya Aichi 466-8555 Japan
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako Saitama 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP), RIKEN 2-1 Hirosawa Wako Saitama 351-0198 Japan
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3
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Chang CF, Kuramochi H, Singh M, Abe-Yoshizumi R, Tsukuda T, Kandori H, Tahara T. A Unified View on Varied Ultrafast Dynamics of the Primary Process in Microbial Rhodopsins. Angew Chem Int Ed Engl 2021; 61:e202111930. [PMID: 34670002 DOI: 10.1002/anie.202111930] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Indexed: 11/08/2022]
Abstract
All-trans to 13-cis photoisomerization of the protonated retinal Schiff base (PRSB) chromophore is the primary step that triggers various biological functions of microbial rhodopsins. While this ultrafast primary process has been extensively studied, it has been recognized that the relevant excited-state relaxation dynamics differ significantly from one rhodopsin to another. To elucidate the origin of the complicated ultrafast dynamics of the primary process in microbial rhodopsins, we studied the excited-state dynamics of proteorhodopsin, its D97N mutant, and bacteriorhodopsin by femtosecond time-resolved absorption (TA) spectroscopy in a wide pH range. The TA data showed that their excited-state relaxation dynamics drastically change when pH approaches the pKa of the counterion residue of the PRSB chromophore in the ground state. This result reveals that the varied excited-state relaxation dynamics in different rhodopsins mainly originate from the difference of the ground-state heterogeneity (i.e., protonation/deprotonation of the PRSB counterion).
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Affiliation(s)
- Chun-Fu Chang
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-0033, Japan
| | - Hikaru Kuramochi
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,PRESTO (Japan) Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama, 332-0012, Japan.,Present address: Research Center of Integrative Molecular Systems, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki, 444-8585, Japan
| | - Manish Singh
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-Ku, Nagoya, Aichi, 466-8555, Japan
| | - Rei Abe-Yoshizumi
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-Ku, Nagoya, Aichi, 466-8555, Japan
| | - Tatsuya Tsukuda
- Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-0033, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-Ku, Nagoya, Aichi, 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-Ku, Nagoya, Aichi, 466-8555, Japan
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
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4
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Liang R, Yu JK, Meisner J, Liu F, Martinez TJ. Electrostatic Control of Photoisomerization in Channelrhodopsin 2. J Am Chem Soc 2021; 143:5425-5437. [PMID: 33794085 DOI: 10.1021/jacs.1c00058] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Channelrhodopsin 2 (ChR2) is the most commonly used tool in optogenetics. Because of its faster photocycle compared to wild-type (WT) ChR2, the E123T mutant of ChR2 is a useful optogenetic tool when fast neuronal stimulation is needed. Interestingly, in spite of its faster photocycle, the initial step of the photocycle in E123T (photoisomerization of retinal protonated Schiff base or RPSB) was found experimentally to be much slower than that of WT ChR2. The E123T mutant replaces the negatively charged E123 residue with a neutral T123 residue, perturbing the electric field around the RPSB. Understanding the RPSB photoisomerization mechanism in ChR2 mutants will provide molecular-level insights into how ChR2 photochemical reactivity can be controlled, which will lay the foundation for improving the design of optogenetic tools. In this work, we combine ab initio nonadiabatic dynamics simulation, excited state free energy calculation, and reaction path search to comprehensively characterize the RPSB photoisomerization mechanism in the E123T mutant of ChR2. Our simulation agrees with previous experiments in predicting a red-shifted absorption spectrum and significant slowdown of photoisomerization in the E123T mutant. Interestingly, our simulations predict similar photoisomerization quantum yields for the mutant and WT despite the differences in excited-state lifetime and absorption maximum. Upon mutation, the neutralization of the negative charge on the E123 residue increases the isomerization barrier, alters the reaction pathway, and changes the relative stability of two fluorescent states. Our findings provide new insight into the intricate role of the electrostatic environment on the RPSB photoisomerization mechanism in microbial rhodopsins.
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Affiliation(s)
- Ruibin Liang
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, United States.,SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Jimmy K Yu
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, United States.,SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States.,Biophysics Program, Stanford University, Stanford, California 94305, United States
| | - Jan Meisner
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, United States.,SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Fang Liu
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, United States.,SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
| | - Todd J Martinez
- Department of Chemistry and The PULSE Institute, Stanford University, Stanford, California 94305, United States.,SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
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5
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Early-stage dynamics of chloride ion-pumping rhodopsin revealed by a femtosecond X-ray laser. Proc Natl Acad Sci U S A 2021; 118:2020486118. [PMID: 33753488 PMCID: PMC8020794 DOI: 10.1073/pnas.2020486118] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Light-driven rhodopsin proteins pump ions across cell membranes. They have applications in optogenetics and can potentially be used to develop solar energy–harvesting devices. A detailed understanding of rhodopsin dynamics and functions may therefore assist research in medicine, health, and clean energy. This time-resolved crystallography study carried out with X-ray free-electron lasers reveals detailed dynamics of chloride ion–pumping rhodopsin (ClR) within 100 ps of light activation. It shows the dissociation of Cl− from the Schiff base binding site upon light-triggered retinal isomerization. This Cl− dissociation is followed by diffusion toward the intracellular direction. The results hint at a common ion-pumping mechanism across rhodopsin families. Chloride ion–pumping rhodopsin (ClR) in some marine bacteria utilizes light energy to actively transport Cl− into cells. How the ClR initiates the transport is elusive. Here, we show the dynamics of ion transport observed with time-resolved serial femtosecond (fs) crystallography using the Linac Coherent Light Source. X-ray pulses captured structural changes in ClR upon flash illumination with a 550 nm fs-pumping laser. High-resolution structures for five time points (dark to 100 ps after flashing) reveal complex and coordinated dynamics comprising retinal isomerization, water molecule rearrangement, and conformational changes of various residues. Combining data from time-resolved spectroscopy experiments and molecular dynamics simulations, this study reveals that the chloride ion close to the Schiff base undergoes a dissociation–diffusion process upon light-triggered retinal isomerization.
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Marsili E, Olivucci M, Lauvergnat D, Agostini F. Quantum and Quantum-Classical Studies of the Photoisomerization of a Retinal Chromophore Model. J Chem Theory Comput 2020; 16:6032-6048. [PMID: 32931266 DOI: 10.1021/acs.jctc.0c00679] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We report an in-depth analysis of the photo-induced isomerization of the 2-cis-penta-2,4-dieniminium cation: a minimal model of the 11-cis retinal protonated Schiff base chromophore of the dim-light photoreceptor rhodopsin. Based on recently developed three-dimensional potentials parametrized on ab initio multi-state multi-configurational second-order perturbation theory data, we perform quantum-dynamical studies. In addition, simulations based on various quantum-classical methods, among which Tully surface hopping and the coupled-trajectory approach derived from the exact factorization, allow us to validate their performance against vibronic wavepacket propagation and, therefore, a purely quantum treatment. Quantum-dynamics results uncover qualitative differences with respect to the two-dimensional Hahn-Stock potentials, widely used as model potentials for the isomerization of the same chromophore, due to the increased dimensionality and three-mode correlation. Quantum-classical simulations show, instead, that three-dimensional model potentials are capable of capturing a number of features revealed by atomistic simulations and experimental observations. In particular, a recently reported vibrational phase relationship between double-bond torsion and hydrogen-out-of-plane modes critical for rhodopsin isomerization efficiency is correctly reproduced.
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Affiliation(s)
- Emanuele Marsili
- Université Paris-Saclay, CNRS, Institut de Chimie Physique UMR8000, Orsay 91405, France.,Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Massimo Olivucci
- Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via A. Moro 2, I-53100 Siena, Italy.,Department of Chemistry, Bowling Green State University, Bowling Green, Ohio 43403, United States
| | - David Lauvergnat
- Université Paris-Saclay, CNRS, Institut de Chimie Physique UMR8000, Orsay 91405, France
| | - Federica Agostini
- Université Paris-Saclay, CNRS, Institut de Chimie Physique UMR8000, Orsay 91405, France
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7
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Groenhof G, Modi V, Morozov D. Observe while it happens: catching photoactive proteins in the act with non-adiabatic molecular dynamics simulations. Curr Opin Struct Biol 2020; 61:106-112. [PMID: 31927414 DOI: 10.1016/j.sbi.2019.12.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/14/2019] [Indexed: 01/24/2023]
Abstract
Organisms use photo-receptors to react to light. The first step is usually the absorption of a photon by a prosthetic group embedded inside the photo-receptor, often a conjugated chromophore. The electronic changes in the chromophore induced by photo-absorption can trigger a cascade of structural or chemical transformations that culminate into a response to light. Understanding how these proteins have evolved to mediate their activation process has remained challenging because the required time and spacial resolutions are notoriously difficult to achieve experimentally. Therefore, mechanistic insights into photoreceptor activation have been predominantly obtained with computer simulations. Here we briefly outline the challenges associated with such computations and review the progress made in this field.
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Affiliation(s)
- Gerrit Groenhof
- Nanoscience Center and Department of Chemistry, P.O. Box 35, 40014 University of Jyväskylä, Finland.
| | - Vaibhav Modi
- Nanoscience Center and Department of Chemistry, P.O. Box 35, 40014 University of Jyväskylä, Finland
| | - Dmitry Morozov
- Nanoscience Center and Department of Chemistry, P.O. Box 35, 40014 University of Jyväskylä, Finland
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8
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First-Principles Characterization of the Elusive I Fluorescent State and the Structural Evolution of Retinal Protonated Schiff Base in Bacteriorhodopsin. J Am Chem Soc 2019; 141:18193-18203. [DOI: 10.1021/jacs.9b08941] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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9
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Thongyod W, Buranachai C, Pengpan T, Punwong C. Fluorescence quenching by photoinduced electron transfer between 7-methoxycoumarin and guanine base facilitated by hydrogen bonds: an in silico study. Phys Chem Chem Phys 2019; 21:16258-16269. [PMID: 31304496 DOI: 10.1039/c9cp02037c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, the effects of hydrogen bond (H-bond) formation on fluorescence quenching of 7-methoxycoumarin (7MC) via photo-induced electron transfer from a guanine base (Gua) are investigated using a combined quantum mechanics/molecular mechanics simulation. The electronic structure is calculated by the floating occupation molecular orbital complete active space configuration interaction modification on a semiempirical method. Then the full multiple spawning method is employed for the dynamics simulations on multiple electronic states. The methods employed here are validated by simulating direct dynamics of 7MC (without Gua) and compared with available experimental results. Our computational results are in good agreement with the previously reported experimental results in terms of spectroscopic properties of 7MC. In the case of a H-bonded 7MC-Gua complex, the results from constrained dynamics simulations and single-point calculations suggest that the electron transfer occurs on the second excited state and it depends not only on the H-bond length but also on the intermolecular planarity between 7MC and Gua. Moreover, a proton coupled electron transfer can occur at ≈1 Å of H-bond length, where a proton from Gua is also transferred together with the electron to 7MC. The obtained simulations are expected to be greatly beneficial for designing effective fluorescently labeled nucleotide probes as well as providing information for precise fluorescence signal interpretation.
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Affiliation(s)
- Wutthinan Thongyod
- Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand. and Center of Excellence for Trace Analysis and Biosensor, Prince of Songkla University, Songkhla 90112, Thailand
| | - Chittanon Buranachai
- Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand. and Center of Excellence for Trace Analysis and Biosensor, Prince of Songkla University, Songkhla 90112, Thailand
| | - Teparksorn Pengpan
- Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand.
| | - Chutintorn Punwong
- Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand.
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10
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Punwong C, Hannongbua S, Martínez TJ. Electrostatic Influence on Photoisomerization in Bacteriorhodopsin and Halorhodopsin. J Phys Chem B 2019; 123:4850-4857. [DOI: 10.1021/acs.jpcb.9b01837] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- C. Punwong
- Department of Physics, Faculty of Science, Prince of Songkla University, Songkhla 90112 Thailand
| | - S. Hannongbua
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - T. J. Martínez
- Department of Chemistry and the PULSE Institute, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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11
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Affiliation(s)
- Basile F. E. Curchod
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Todd J. Martínez
- Department of Chemistry and PULSE Institute, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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12
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Gozem S, Luk HL, Schapiro I, Olivucci M. Theory and Simulation of the Ultrafast Double-Bond Isomerization of Biological Chromophores. Chem Rev 2017; 117:13502-13565. [DOI: 10.1021/acs.chemrev.7b00177] [Citation(s) in RCA: 175] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Samer Gozem
- Department
of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
| | - Hoi Ling Luk
- Chemistry
Department, Bowling Green State University, Overman Hall, Bowling Green, Ohio 43403, United States
| | - Igor Schapiro
- Fritz
Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Massimo Olivucci
- Chemistry
Department, Bowling Green State University, Overman Hall, Bowling Green, Ohio 43403, United States
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università di Siena, via A. Moro
2, 53100 Siena, Italy
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13
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Pijeau S, Hohenstein EG. Improved Complete Active Space Configuration Interaction Energies with a Simple Correction from Density Functional Theory. J Chem Theory Comput 2017; 13:1130-1146. [DOI: 10.1021/acs.jctc.6b00893] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Shiela Pijeau
- Department
of Chemistry and Biochemistry, The City College of New York, New York, New York 10031, United States
| | - Edward G. Hohenstein
- Department
of Chemistry and Biochemistry, The City College of New York, New York, New York 10031, United States
- Ph.D.
Program in Chemistry, The City University of New York, New York, New York 10016, United States
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14
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Hohenstein EG. Analytic formulation of derivative coupling vectors for complete active space configuration interaction wavefunctions with floating occupation molecular orbitals. J Chem Phys 2016; 145:174110. [DOI: 10.1063/1.4966235] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Edward G. Hohenstein
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York 10031, USA and Ph.D. Program in Chemistry, The City University of New York, New York, New York 10016, USA
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15
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Liu L, Cui G, Fang WH. Excited States and Photochemistry of Chromophores in the Photoactive Proteins Explored by the Combined Quantum Mechanical and Molecular Mechanical Calculations. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2015; 100:255-84. [PMID: 26415847 DOI: 10.1016/bs.apcsb.2015.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A photoactive protein usually contains a unique chromophore that is responsible for the initial photoresponse and functions of the photoactive protein are determined by the interaction between the chromophore and its protein surroundings. The combined quantum mechanical and molecular mechanical (QM/MM) approach is demonstrated to be a very useful tool for exploring structures and functions of a photoactive protein with the chromophore and its protein surroundings treated by the QM and MM methods, respectively. In this review, we summarize the basic formulas of the QM/MM approach and emphasize its applications to excited states and photoreactions of chromophores in rhodopsin protein, photoactive yellow protein, and green fluorescent protein.
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Affiliation(s)
- Lihong Liu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China.
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
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