1
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Lamm GHU, Zabelskii D, Balandin T, Gordeliy V, Wachtveitl J. Calcium-Sensitive Microbial Rhodopsin VirChR1: A Femtosecond to Second Photocycle Study. J Phys Chem Lett 2024; 15:5510-5516. [PMID: 38749015 DOI: 10.1021/acs.jpclett.4c00693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2024]
Abstract
Viral rhodopsins are light-gated cation channels representing a novel class of microbial rhodopsins. For viral rhodopsin 1 subfamily members VirChR1 and OLPVR1, channel activity is abolished above a certain calcium concentration. Here we present a calcium-dependent spectroscopic analysis of VirChR1 on the femtosecond to second time scale. Unlike channelrhodopsin-2, VirChR1 possesses two intermediate states P1 and P2 on the ultrafast time scale, similar to J and K in ion-pumping rhodopsins. Subsequently, we observe multifaceted photocycle kinetics with up to seven intermediate states. Calcium predominantly affects the last photocycle steps, including the appearance of additional intermediates P6Ca and P7 representing the blocked channel. Furthermore, the photocycle of the counterion variant D80N is drastically altered, yielding intermediates with different spectra and kinetics compared to those of the wt. These findings demonstrate the central role of the counterion within the defined reaction sequence of microbial rhodopsins that ultimately defines the protein function.
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Affiliation(s)
- Gerrit H U Lamm
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | | | - Taras Balandin
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Valentin Gordeliy
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
- University Grenoble Alpes, CEA, CNRS, Institute de Biologie Structurale (IBS), 38000 Grenoble, France
| | - Josef Wachtveitl
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
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2
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Malakar P, Gholami S, Aarabi M, Rivalta I, Sheves M, Garavelli M, Ruhman S. Retinal photoisomerization versus counterion protonation in light and dark-adapted bacteriorhodopsin and its primary photoproduct. Nat Commun 2024; 15:2136. [PMID: 38459010 PMCID: PMC10923925 DOI: 10.1038/s41467-024-46061-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 02/08/2024] [Indexed: 03/10/2024] Open
Abstract
Discovered over 50 years ago, bacteriorhodopsin is the first recognized and most widely studied microbial retinal protein. Serving as a light-activated proton pump, it represents the archetypal ion-pumping system. Here we compare the photochemical dynamics of bacteriorhodopsin light and dark-adapted forms with that of the first metastable photocycle intermediate known as "K". We observe that following thermal double isomerization of retinal in the dark from bio-active all-trans 15-anti to 13-cis, 15-syn, photochemistry proceeds even faster than the ~0.5 ps decay of the former, exhibiting ballistic wave packet curve crossing to the ground state. In contrast, photoexcitation of K containing a 13-cis, 15-anti chromophore leads to markedly multi-exponential excited state decay including much slower stages. QM/MM calculations, aimed to interpret these results, highlight the crucial role of protonation, showing that the classic quadrupole counterion model poorly reproduces spectral data and dynamics. Single protonation of ASP212 rectifies discrepancies and predicts triple ground state structural heterogeneity aligning with experimental observations. These findings prompt a reevaluation of counter ion protonation in bacteriorhodopsin and contribute to the broader understanding of its photochemical dynamics.
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Affiliation(s)
- Partha Malakar
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Samira Gholami
- Dipartimento di Chimica industriale "Toso Montanari", Università di Bologna, Viale del Risorgimento 4, 40136, Bologna, Italy
| | - Mohammad Aarabi
- Dipartimento di Chimica industriale "Toso Montanari", Università di Bologna, Viale del Risorgimento 4, 40136, Bologna, Italy
| | - Ivan Rivalta
- Dipartimento di Chimica industriale "Toso Montanari", Università di Bologna, Viale del Risorgimento 4, 40136, Bologna, Italy
- ENSL, CNRS, Laboratoire de Chimie UMR 5182, 46 allée d'Italie, 69364, Lyon, France
| | - Mordechai Sheves
- Department of Molecular Chemistry and Materials Science, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
| | - Marco Garavelli
- Dipartimento di Chimica industriale "Toso Montanari", Università di Bologna, Viale del Risorgimento 4, 40136, Bologna, Italy.
| | - Sanford Ruhman
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
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3
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Nikolaev DM, Shtyrov AA, Vyazmin SY, Vasin AV, Panov MS, Ryazantsev MN. Fluorescence of the Retinal Chromophore in Microbial and Animal Rhodopsins. Int J Mol Sci 2023; 24:17269. [PMID: 38139098 PMCID: PMC10743670 DOI: 10.3390/ijms242417269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 11/30/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Fluorescence of the vast majority of natural opsin-based photoactive proteins is extremely low, in accordance with their functions that depend on efficient transduction of absorbed light energy. However, several recently proposed classes of engineered rhodopsins with enhanced fluorescence, along with the discovery of a new natural highly fluorescent rhodopsin, NeoR, opened a way to exploit these transmembrane proteins as fluorescent sensors and draw more attention to studies on this untypical rhodopsin property. Here, we review the available data on the fluorescence of the retinal chromophore in microbial and animal rhodopsins and their photocycle intermediates, as well as different isomers of the protonated retinal Schiff base in various solvents and the gas phase.
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Affiliation(s)
- Dmitrii M. Nikolaev
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 St. Petersburg, Russia
| | - Andrey A. Shtyrov
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 St. Petersburg, Russia
| | - Sergey Yu. Vyazmin
- Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, 8/3 Khlopina Street, 194021 St. Petersburg, Russia
| | - Andrey V. Vasin
- Institute of Biomedical Systems and Biotechnologies, Peter the Great St. Petersburg Polytechnic University, 29 Polytechnicheskaya Str., 195251 St. Petersburg, Russia
| | - Maxim S. Panov
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 St. Petersburg, Russia
- Center for Biophysical Studies, St. Petersburg State Chemical Pharmaceutical University, Professor Popov str. 14, lit. A, 197022 St. Petersburg, Russia
| | - Mikhail N. Ryazantsev
- Institute of Chemistry, Saint Petersburg State University, 26 Universitetskii pr, 198504 St. Petersburg, Russia
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4
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Bühl E, Resler T, Lam R, Asido M, Bamberg E, Schlesinger R, Bamann C, Heberle J, Wachtveitl J. Assessing the Role of R120 in the Gating of CrChR2 by Time-Resolved Spectroscopy from Femtoseconds to Seconds. J Am Chem Soc 2023; 145:21832-21840. [PMID: 37773976 DOI: 10.1021/jacs.3c05399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2023]
Abstract
The light-gated ion channel channelrhodopsin-2 from Chlamydomonas reinhardtii (CrChR2) is the most frequently used optogenetic tool in neurosciences. However, the precise molecular mechanism of the channel opening and the correlation among retinal isomerization, the photocycle, and the channel activity of the protein are missing. Here, we present electrophysiological and spectroscopic investigations on the R120H variant of CrChR2. R120 is a key residue in an extended network linking the retinal chromophore to several gates of the ion channel. We show that despite the deficient channel activity, the photocycle of the variant is intact. In a comparative study for R120H and the wild type, we resolve the vibrational changes in the spectral range of the retinal and amide I bands across the time range from femtoseconds to seconds. Analysis of the amide I mode reveals a significant impairment of the ultrafast protein response after retinal excitation. We conclude that channel opening in CrChR2 is prepared immediately after retinal excitation. Additionally, chromophore isomerization is essential for both photocycle and channel activities, although both processes can occur independently.
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Affiliation(s)
- Elena Bühl
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt am Main, Max-von-Laue Strasse 7, 60438 Frankfurt, Germany
| | - Tom Resler
- Department of Physics, Experimental Molecular Biophysics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Rebecca Lam
- Max Planck Institute of Biophysics, Max-von-Laue Strasse 3, 60438 Frankfurt am Main, Germany
| | - Marvin Asido
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt am Main, Max-von-Laue Strasse 7, 60438 Frankfurt, Germany
| | - Ernst Bamberg
- Max Planck Institute of Biophysics, Max-von-Laue Strasse 3, 60438 Frankfurt am Main, Germany
| | - Ramona Schlesinger
- Department of Physics, Genetic Biophysics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Christian Bamann
- Max Planck Institute of Biophysics, Max-von-Laue Strasse 3, 60438 Frankfurt am Main, Germany
| | - Joachim Heberle
- Department of Physics, Experimental Molecular Biophysics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Josef Wachtveitl
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt am Main, Max-von-Laue Strasse 7, 60438 Frankfurt, Germany
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5
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Meng X, Ganapathy S, van Roemburg L, Post M, Brinks D. Voltage Imaging with Engineered Proton-Pumping Rhodopsins: Insights from the Proton Transfer Pathway. ACS PHYSICAL CHEMISTRY AU 2023; 3:320-333. [PMID: 37520318 PMCID: PMC10375888 DOI: 10.1021/acsphyschemau.3c00003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/13/2023] [Accepted: 04/13/2023] [Indexed: 08/01/2023]
Abstract
Voltage imaging using genetically encoded voltage indicators (GEVIs) has taken the field of neuroscience by storm in the past decade. Its ability to create subcellular and network level readouts of electrical dynamics depends critically on the kinetics of the response to voltage of the indicator used. Engineered microbial rhodopsins form a GEVI subclass known for their high voltage sensitivity and fast response kinetics. Here we review the essential aspects of microbial rhodopsin photocycles that are critical to understanding the mechanisms of voltage sensitivity in these proteins and link them to insights from efforts to create faster, brighter and more sensitive microbial rhodopsin-based GEVIs.
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Affiliation(s)
- Xin Meng
- Department
of Imaging Physics, Delft University of
Technology, 2628 CJ Delft, The
Netherlands
| | - Srividya Ganapathy
- Department
of Imaging Physics, Delft University of
Technology, 2628 CJ Delft, The
Netherlands
- Department
of Pediatrics & Cellular and Molecular Medicine, UCSD School of Medicine, La Jolla, California 92093, United States
| | - Lars van Roemburg
- Department
of Imaging Physics, Delft University of
Technology, 2628 CJ Delft, The
Netherlands
| | - Marco Post
- Department
of Imaging Physics, Delft University of
Technology, 2628 CJ Delft, The
Netherlands
| | - Daan Brinks
- Department
of Imaging Physics, Delft University of
Technology, 2628 CJ Delft, The
Netherlands
- Department
of Molecular Genetics, Erasmus University
Medical Center, 3015 GD Rotterdam, The Netherlands
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6
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QuasAr Odyssey: the origin of fluorescence and its voltage sensitivity in microbial rhodopsins. Nat Commun 2022; 13:5501. [PMID: 36127376 PMCID: PMC9489792 DOI: 10.1038/s41467-022-33084-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 08/26/2022] [Indexed: 11/29/2022] Open
Abstract
Rhodopsins had long been considered non-fluorescent until a peculiar voltage-sensitive fluorescence was reported for archaerhodopsin-3 (Arch3) derivatives. These proteins named QuasArs have been used for imaging membrane voltage changes in cell cultures and small animals. However due to the low fluorescence intensity, these constructs require use of much higher light intensity than other optogenetic tools. To develop the next generation of sensors, it is indispensable to first understand the molecular basis of the fluorescence and its modulation by the membrane voltage. Based on spectroscopic studies of fluorescent Arch3 derivatives, we propose a unique photo-reaction scheme with extended excited-state lifetimes and inefficient photoisomerization. Molecular dynamics simulations of Arch3, of the Arch3 fluorescent derivative Archon1, and of several its mutants have revealed different voltage-dependent changes of the hydrogen-bonding networks including the protonated retinal Schiff-base and adjacent residues. Experimental observations suggest that under negative voltage, these changes modulate retinal Schiff base deprotonation and promote a decrease in the populations of fluorescent species. Finally, we identified molecular constraints that further improve fluorescence quantum yield and voltage sensitivity. The authors present an in-depth investigation of excited state dynamics and molecular mechanism of the voltage sensing in microbial rhodopsins. Using a combination of spectroscopic investigations and molecular dynamics simulations, the study proposes the voltage-modulated deprotonation of the chromophore as the key event in the voltage sensing. Thus, molecular constraints that may further improve the fluorescence quantum yield and the voltage sensitivity are presented.
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7
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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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8
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Grünbein ML, Kovacs GN, Kloos M, Gorel A, Doak RB, Shoeman RL, Barends TRM, Schlichting I. Crystallographic Studies of Rhodopsins: Structure and Dynamics. Methods Mol Biol 2022; 2501:147-168. [PMID: 35857227 DOI: 10.1007/978-1-0716-2329-9_7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Crystal structures have provided detailed insight in the architecture of rhodopsin photoreceptors. Of particular interest are the protein-chromophore interactions that govern the light-induced retinal isomerization and ultimately induce the large structural changes important for the various biological functions of the family. The reaction intermediates occurring along the rhodopsin photocycle have vastly differing lifetimes, from hundreds of femtoseconds to milliseconds. Detailed insight at high spatial and temporal resolution can be obtained by time-resolved crystallography using pump-probe approaches at X-ray free-electron lasers. Alternatively, cryotrapping approaches can be used. Both the approaches are described, including illumination and sample delivery. The importance of appropriate photoexcitation avoiding multiphoton absorption is stressed.
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Affiliation(s)
| | | | - Marco Kloos
- Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Alexander Gorel
- Max Planck Institute for Medical Research, Heidelberg, Germany
| | - R Bruce Doak
- Max Planck Institute for Medical Research, Heidelberg, Germany
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9
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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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10
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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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11
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Jenkins AJ, Gottlieb SM, Chang CW, Kim PW, Hayer RJ, Hanke SJ, Martin SS, Lagarias JC, Larsen DS. Conservation and Diversity in the Primary Reverse Photodynamics of the Canonical Red/Green Cyanobacteriochrome Family. Biochemistry 2020; 59:4015-4028. [PMID: 33021375 DOI: 10.1021/acs.biochem.0c00454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this report, we compare the femtosecond to nanosecond primary reverse photodynamics (15EPg → 15ZPr) of eight tetrapyrrole binding photoswitching cyanobacteriochromes in the canonical red/green family from the cyanobacterium Nostoc punctiforme. Three characteristic classes were identified on the basis of the diversity of excited-state and ground-state properties, including the lifetime, photocycle initiation quantum yield, photointermediate stability, spectra, and temporal properties. We observed a correlation between the excited-state lifetime and peak wavelength of the electronic absorption spectrum with higher-energy-absorbing representatives exhibiting both faster excited-state decay times and higher photoisomerization quantum yields. The latter was attributed to both an increased number of structural restraints and differences in H-bonding networks that facilitate photoisomerization. All three classes exhibited primary Lumi-Go intermediates, with class II and III representatives evolving to a secondary Meta-G photointermediate. Class II Meta-GR intermediates were orange absorbing, whereas class III Meta-G had structurally relaxed, red-absorbing chromophores that resemble their dark-adapted 15ZPr states. Differences in the reverse and forward reaction mechanisms are discussed within the context of structural constraints.
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Affiliation(s)
- Adam J Jenkins
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Sean Marc Gottlieb
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Che-Wei Chang
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Peter W Kim
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Randeep J Hayer
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Samuel J Hanke
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Shelley S Martin
- Department of Molecular and Cellular Biology, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - J Clark Lagarias
- Department of Molecular and Cellular Biology, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Delmar S Larsen
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
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12
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Yun JH, Ohki M, Park JH, Ishimoto N, Sato-Tomita A, Lee W, Jin Z, Tame JRH, Shibayama N, Park SY, Lee W. Pumping mechanism of NM-R3, a light-driven bacterial chloride importer in the rhodopsin family. SCIENCE ADVANCES 2020; 6:eaay2042. [PMID: 32083178 PMCID: PMC7007266 DOI: 10.1126/sciadv.aay2042] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
A newly identified microbial rhodopsin, NM-R3, from the marine flavobacterium Nonlabens marinus, was recently shown to drive chloride ion uptake, extending our understanding of the diversity of mechanisms for biological energy conversion. To clarify the mechanism underlying its function, we characterized the crystal structures of NM-R3 in both the dark state and early intermediate photoexcited states produced by laser pulses of different intensities and temperatures. The displacement of chloride ions at five different locations in the model reflected the detailed anion-conduction pathway, and the activity-related key residues-Cys105, Ser60, Gln224, and Phe90-were identified by mutation assays and spectroscopy. Comparisons with other proteins, including a closely related outward sodium ion pump, revealed key motifs and provided structural insights into light-driven ion transport across membranes by the NQ subfamily of rhodopsins. Unexpectedly, the response of the retinal in NM-R3 to photostimulation appears to be substantially different from that seen in bacteriorhodopsin.
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Affiliation(s)
- Ji-Hye Yun
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Mio Ohki
- Research Complex at Harwell, Rutherford Appleton Laboratory, OX11 0FA Didcot, UK
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama 230-0045, Japan
| | - Jae-Hyun Park
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Naito Ishimoto
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama 230-0045, Japan
| | - Ayana Sato-Tomita
- Division of Biophysics, Department of Physiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Wonbin Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Zeyu Jin
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Jeremy R. H. Tame
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama 230-0045, Japan
| | - Naoya Shibayama
- Division of Biophysics, Department of Physiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Sam-Yong Park
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama 230-0045, Japan
| | - Weontae Lee
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
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13
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Liu S, Fu R, Li G. Exploring the mechanism of olfactory recognition in the initial stage by modeling the emission spectrum of electron transfer. PLoS One 2020; 15:e0217665. [PMID: 31923248 PMCID: PMC6953861 DOI: 10.1371/journal.pone.0217665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 11/29/2019] [Indexed: 11/19/2022] Open
Abstract
Olfactory sense remains elusive regarding the primary reception mechanism. Some studies suggest that olfaction is a spectral sense, the olfactory event is triggered by electron transfer (ET) across the odorants at the active sites of odorant receptors (ORs). Herein we present a Donor-Bridge-Acceptor model, proposing that the ET process can be viewed as an electron hopping from the donor molecule to the odorant molecule (Bridge), then hopping off to the acceptor molecule, making the electronic state of the odorant molecule change along with vibrations (vibronic transition). The odorant specific parameter, Huang–Rhys factor can be derived from ab initio calculations, which make the simulation of ET spectra achievable. In this study, we revealed that the emission spectra (after Gaussian convolution) can be acted as odor characteristic spectra. Using the emission spectrum of ET, we were able to reasonably interpret the similar bitter-almond odors among hydrogen cyanide, benzaldehyde and nitrobenzene. In terms of isotope effects, we succeeded in explaining why subjects can easily distinguish cyclopentadecanone from its fully deuterated analogue cyclopentadecanone-d28 but not distinguishing acetophenone from acetophenone-d8.
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Affiliation(s)
- Shu Liu
- Department of Anatomy, Anhui Medical University, Hefei, Anhui, China
- * E-mail:
| | - Rao Fu
- Department of Anatomy, School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Guangwu Li
- Department of Anatomy, Anhui Medical University, Hefei, Anhui, China
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14
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Huang HY, Syue ML, Chen IC, Yu TY, Chu LK. Influence of Lipid Compositions in the Events of Retinal Schiff Base of Bacteriorhodopsin Embedded in Covalently Circularized Nanodiscs: Thermal Isomerization, Photoisomerization, and Deprotonation. J Phys Chem B 2019; 123:9123-9133. [PMID: 31584816 DOI: 10.1021/acs.jpcb.9b07788] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Covalently circularized nanodiscs using circular membrane scaffold protein (MSP) serve as a suitable membrane mimetic for transmembrane proteins by providing stability and tunability in lipid compositions, providing controllable biological environments for targeted proteins. In this work, monomeric bacteriorhodopsin (mbR) was embedded in lipid nanodiscs of different lipid compositions using negatively charged lipid dioleoyl phosphatidylglycerol (DOPG) and the zwitterion lipid dioleoyl phosphatidylcholine (DOPC), and the events associated with the retinal Schiff base, including the thermal isomerization during the dark adaptation, photoisomerization, and deprotonation, were investigated. The retinal thermal isomerization from all-trans, 15-anti to the 13-cis, 15-syn configuration during the dark adaptation was accelerated in the DOPG bilayer, whereas the processes in the DOPC bilayer and in Triton X-100 micelles were similar. This observation indicated that the negatively charged lipid reduced the barrier for retinal thermal isomerization at C13═C14-C15═N in the ground electronic state. Furthermore, the broader absorption contour of mbR in the DOPC nanodisc probably indicated various retinal isomers in the light-adapted state, consistent with the observed nontwo-state dark adaptation kinetics. Moreover, the kinetics of the photoisomerization of the retinal was slightly decelerated upon increasing the content of DOPC. However, the cascading deprotonation of the protonated Schiff base is not dependent on the types of the surrounding lipids in the nanodiscs. In summary, our research deepens the understanding of the coupling between lipid membrane and the photochemistry of bR retinal Schiff base. Combined with the results of our previous works (Lee, T.-Y.; Yeh, V.; Chuang, J.; Chan, J. C. C.; Chu, L.-K.; Yu, T.-Y. Biophys. J. 2015, 109, 1899-1906; Kao, Y.-M.; Cheng, C.-H.; Syue, M.-L.; Huang, H.-Y.; Chen, I-C.; Yu, T.-Y.; Chu, L.-K. J. Phys. Chem. B 2019, 123, 2032-2039), these outcomes extend our understanding of the control of photochemistry and biophysical events for other photosynthetic proteins via altering the lipid environments.
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Affiliation(s)
- Hsin-Yu Huang
- Department of Chemistry , National Tsing Hua University , 101, Sec. 2, Kuang-Fu Road , Hsinchu 30013 , Taiwan
| | - Ming-Lun Syue
- Department of Chemistry , National Tsing Hua University , 101, Sec. 2, Kuang-Fu Road , Hsinchu 30013 , Taiwan
| | - I-Chia Chen
- Department of Chemistry , National Tsing Hua University , 101, Sec. 2, Kuang-Fu Road , Hsinchu 30013 , Taiwan
| | - Tsyr-Yan Yu
- Institute of Atomic and Molecular Sciences, Academia Sinica , 1, Sec. 4, Roosevelt Road , Taipei 10617 , Taiwan.,International Graduate Program of Molecular Science and Technology , National Taiwan University , Taipei , Taiwan
| | - Li-Kang Chu
- Department of Chemistry , National Tsing Hua University , 101, Sec. 2, Kuang-Fu Road , Hsinchu 30013 , Taiwan
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15
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Nass Kovacs G, Colletier JP, Grünbein ML, Yang Y, Stensitzki T, Batyuk A, Carbajo S, Doak RB, Ehrenberg D, Foucar L, Gasper R, Gorel A, Hilpert M, Kloos M, Koglin JE, Reinstein J, Roome CM, Schlesinger R, Seaberg M, Shoeman RL, Stricker M, Boutet S, Haacke S, Heberle J, Heyne K, Domratcheva T, Barends TRM, Schlichting I. Three-dimensional view of ultrafast dynamics in photoexcited bacteriorhodopsin. Nat Commun 2019; 10:3177. [PMID: 31320619 PMCID: PMC6639342 DOI: 10.1038/s41467-019-10758-0] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 05/28/2019] [Indexed: 11/10/2022] Open
Abstract
Bacteriorhodopsin (bR) is a light-driven proton pump. The primary photochemical event upon light absorption is isomerization of the retinal chromophore. Here we used time-resolved crystallography at an X-ray free-electron laser to follow the structural changes in multiphoton-excited bR from 250 femtoseconds to 10 picoseconds. Quantum chemistry and ultrafast spectroscopy were used to identify a sequential two-photon absorption process, leading to excitation of a tryptophan residue flanking the retinal chromophore, as a first manifestation of multiphoton effects. We resolve distinct stages in the structural dynamics of the all-trans retinal in photoexcited bR to a highly twisted 13-cis conformation. Other active site sub-picosecond rearrangements include correlated vibrational motions of the electronically excited retinal chromophore, the surrounding amino acids and water molecules as well as their hydrogen bonding network. These results show that this extended photo-active network forms an electronically and vibrationally coupled system in bR, and most likely in all retinal proteins. Bacteriorhodopsin (bR) is a light-driven proton pump. Here the authors combine time-resolved crystallography at a free-electron laser, ultrafast spectroscopy and quantum chemistry to study the structural changes following multiphoton photoexcitation of bR and find that they occur within 300 fs not only in the light-absorbing chromophore but also in the surrounding protein.
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Affiliation(s)
- Gabriela Nass Kovacs
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Jacques-Philippe Colletier
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale, 71 Avenue des Martyrs, 38000, Grenoble, France
| | - Marie Luise Grünbein
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Yang Yang
- Freie Universität Berlin, Department of Physics, Arnimallee 14, 14195, Berlin, Germany
| | - Till Stensitzki
- Freie Universität Berlin, Department of Physics, Arnimallee 14, 14195, Berlin, Germany
| | - Alexander Batyuk
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Sergio Carbajo
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - R Bruce Doak
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - David Ehrenberg
- Freie Universität Berlin, Department of Physics, Arnimallee 14, 14195, Berlin, Germany
| | - Lutz Foucar
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Raphael Gasper
- Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Str. 11, 44227, Dortmund, Germany
| | - Alexander Gorel
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Mario Hilpert
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Marco Kloos
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Jason E Koglin
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Jochen Reinstein
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Christopher M Roome
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Ramona Schlesinger
- Freie Universität Berlin, Department of Physics, Arnimallee 14, 14195, Berlin, Germany
| | - Matthew Seaberg
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Robert L Shoeman
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Miriam Stricker
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Sébastien Boutet
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Stefan Haacke
- Université de Strasbourg-CNRS, UMR 7504, IPCMS, 23 Rue du Loess, 67034, Strasbourg, France
| | - Joachim Heberle
- Freie Universität Berlin, Department of Physics, Arnimallee 14, 14195, Berlin, Germany
| | - Karsten Heyne
- Freie Universität Berlin, Department of Physics, Arnimallee 14, 14195, Berlin, Germany
| | - Tatiana Domratcheva
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany.
| | - Thomas R M Barends
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Ilme Schlichting
- Max-Planck-Institut für Medizinische Forschung, Jahnstraße 29, 69120, Heidelberg, Germany.
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16
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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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17
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Roy PP, Abe-Yoshizumi R, Kandori H, Buckup T. Point Mutation of Anabaena Sensory Rhodopsin Enhances Ground-State Hydrogen Out-of-Plane Wag Raman Activity. J Phys Chem Lett 2019; 10:1012-1017. [PMID: 30742765 DOI: 10.1021/acs.jpclett.8b03805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The interaction between the retinal protonated Schiff base (RPSB) and surrounding protein residues inside the retinal pocket is believed to play a major role in the ultrafast isomerization of the former. Coherent time-resolved vibrational spectroscopic techniques are applied to reveal the effect of changes in the protein architecture by point mutations (V112N and L83Q) close to the RPSB in Anabaena sensory rhodopsin (ASR). Our study reveals that such point mutations have a minor effect on the low-frequency (<400 cm-1) torsional modes but dramatically influence the ground-state vibrational Raman activity of the C14-H out-of-plane (HOOP) wag mode (800-820 cm-1). In mutated ASR, the increase of HOOP Raman activity in the ground state is experimentally observed for the all- trans RPSB, which has shorter excited-state lifetime than in wild-type ASR. This indicates that predistortion of the RPSB inside the mutated retinal pocket is a major factor in the acceleration of the isomerization rate.
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Affiliation(s)
- Partha Pratim Roy
- Physikalisch-Chemisches Institut , Ruprecht-Karls Universität Heidelberg , D-69120 Heidelberg , Germany
| | - Rei Abe-Yoshizumi
- Department of Life Science and Applied Chemistry , Nagoya Institute of Technology , Showa-ku, Nagoya 466-8555 , Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry , Nagoya Institute of Technology , Showa-ku, Nagoya 466-8555 , Japan
- OptoBioTechnology Research Center , Nagoya Institute of Technology , Showa-ku, Nagoya 466-8555 , Japan
| | - Tiago Buckup
- Physikalisch-Chemisches Institut , Ruprecht-Karls Universität Heidelberg , D-69120 Heidelberg , Germany
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18
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Kao YM, Cheng CH, Syue ML, Huang HY, Chen IC, Yu TY, Chu LK. Photochemistry of Bacteriorhodopsin with Various Oligomeric Statuses in Controlled Membrane Mimicking Environments: A Spectroscopic Study from Femtoseconds to Milliseconds. J Phys Chem B 2019; 123:2032-2039. [DOI: 10.1021/acs.jpcb.9b01224] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yu-Min Kao
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Chung-Hao Cheng
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Ming-Lun Syue
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Hsin-Yu Huang
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - I-Chia Chen
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Tsyr-Yan Yu
- Institute of Atomic and Molecular Sciences, Academia Sinica, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
- International Graduate Program of Molecular Science and Technology, National Taiwan University, Taipei, Taiwan
| | - Li-Kang Chu
- Department of Chemistry, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
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19
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Marín MDC, Agathangelou D, Orozco-Gonzalez Y, Valentini A, Kato Y, Abe-Yoshizumi R, Kandori H, Choi A, Jung KH, Haacke S, Olivucci M. Fluorescence Enhancement of a Microbial Rhodopsin via Electronic Reprogramming. J Am Chem Soc 2018; 141:262-271. [PMID: 30532962 DOI: 10.1021/jacs.8b09311] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The engineering of microbial rhodopsins with enhanced fluorescence is of great importance in the expanding field of optogenetics. Here we report the discovery of two mutants (W76S/Y179F and L83Q) of a sensory rhodopsin from the cyanobacterium Anabaena PCC7120 with opposite fluorescence behavior. In fact, while W76S/Y179F displays, with respect to the wild-type protein, a nearly 10-fold increase in red-light emission, the second is not emissive. Thus, the W76S/Y179F, L83Q pair offers an unprecedented opportunity for the investigation of fluorescence enhancement in microbial rhodopsins, which is pursued by combining transient absorption spectroscopy and multiconfigurational quantum chemistry. The results of such an investigation point to an isomerization-blocking electronic effect as the direct cause of instantaneous (subpicosecond) fluorescence enhancement.
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Affiliation(s)
- María Del Carmen Marín
- Biotechnology, Pharmacy and Chemistry Department , University of Siena , Siena 53100 , Italy.,Chemistry Department , Bowling Green State University , Bowling Green , Ohio 43403 , United States
| | - Damianos Agathangelou
- University of Strasbourg-CNRS , Institute of Physics and Chemistry of Materials of Strasbourg , 67034 Strasbourg , France
| | - Yoelvis Orozco-Gonzalez
- Chemistry Department , Bowling Green State University , Bowling Green , Ohio 43403 , United States.,Université de Strasbourg , USIAS Institut d'Études Avanceés , 67083 Strasbourg , France
| | - Alessio Valentini
- Theoretical Physical Chemistry , UR Molsys, University of Liège , Liège , Belgium
| | - Yoshitaka Kato
- Department of Life Science and Applied Chemistry , Nagoya Institute of Technology , Showa-ku , Nagoya 466-8555 , Japan
| | - Rei Abe-Yoshizumi
- Department of Life Science and Applied Chemistry , Nagoya Institute of Technology , Showa-ku , Nagoya 466-8555 , Japan.,OptoBioTechnology Research Center , Nagoya Institute of Technology , Showa-ku , Nagoya 466-8555 , Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry , Nagoya Institute of Technology , Showa-ku , Nagoya 466-8555 , Japan.,OptoBioTechnology Research Center , Nagoya Institute of Technology , Showa-ku , Nagoya 466-8555 , Japan
| | - Ahreum Choi
- Department of Life Science and Institute of Biological Interfaces , Sogang University , Sogang 04107 , South Korea
| | - Kwang-Hwan Jung
- Department of Life Science and Institute of Biological Interfaces , Sogang University , Sogang 04107 , South Korea
| | - Stefan Haacke
- University of Strasbourg-CNRS , Institute of Physics and Chemistry of Materials of Strasbourg , 67034 Strasbourg , France
| | - Massimo Olivucci
- Biotechnology, Pharmacy and Chemistry Department , University of Siena , Siena 53100 , Italy.,Chemistry Department , Bowling Green State University , Bowling Green , Ohio 43403 , United States.,Université de Strasbourg , USIAS Institut d'Études Avanceés , 67083 Strasbourg , France
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20
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El-Tahawy MMT, Nenov A, Weingart O, Olivucci M, Garavelli M. Relationship between Excited State Lifetime and Isomerization Quantum Yield in Animal Rhodopsins: Beyond the One-Dimensional Landau-Zener Model. J Phys Chem Lett 2018; 9:3315-3322. [PMID: 29791163 PMCID: PMC6650607 DOI: 10.1021/acs.jpclett.8b01062] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We show that the speed of the chromophore photoisomerization of animal rhodopsins is not a relevant control knob for their light sensitivity. This result is at odds with the momentum-driven tunnelling rationale (i.e., assuming a one-dimensional Landau-Zener model for the decay: Zener, C. Non-Adiabatic Crossing of Energy Levels. Proc. R. Soc. London, Ser. A 1932, 137 (833), 696-702) holding that a faster nuclear motion through the conical intersection translates into a higher quantum yield and, thus, light sensitivity. Instead, a model based on the phase-matching of specific excited state vibrational modes should be considered. Using extensive semiclassical hybrid quantum mechanics/molecular mechanics trajectory computations to simulate the photoisomerization of three animal rhodopsin models (visual rhodopsin, squid rhodopsin and human melanopsin), we also demonstrate that phase-matching between three different modes (the reactive carbon and hydrogen twisting coordinates and the bond length alternation mode) is required to achieve high quantum yields. In fact, such "phase-matching" mechanism explains the computational results and provides a tool for the prediction of the photoisomerization outcome in retinal proteins.
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Affiliation(s)
- Mohsen M. T. El-Tahawy
- Dipartimento di Chimica Industriale “Toso Montanari″, Università degli Studi di Bologna, Viale del Risorgimento, 4I -40136 Bologna, Italy
- Chemistry Department, Faculty of Science, Damanhour University, Damanhour 22511, Egypt
| | - Artur Nenov
- Dipartimento di Chimica Industriale “Toso Montanari″, Università degli Studi di Bologna, Viale del Risorgimento, 4I -40136 Bologna, Italy
| | - Oliver Weingart
- Institut für Theoretische Chemie und Computerchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Massimo Olivucci
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, I-53100 Siena, Italy
- Chemistry Department, Bowling Green State University, Bowling Green, OH 43403
- Corresponding Author; (M.O.): ; Phone: +39 051 20 9 9476. Fax: +39 051 20 9 9456 (M.G.)
| | - Marco Garavelli
- Dipartimento di Chimica Industriale “Toso Montanari″, Università degli Studi di Bologna, Viale del Risorgimento, 4I -40136 Bologna, Italy
- Corresponding Author; (M.O.): ; Phone: +39 051 20 9 9476. Fax: +39 051 20 9 9456 (M.G.)
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21
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Nogly P, Weinert T, James D, Carbajo S, Ozerov D, Furrer A, Gashi D, Borin V, Skopintsev P, Jaeger K, Nass K, Båth P, Bosman R, Koglin J, Seaberg M, Lane T, Kekilli D, Brünle S, Tanaka T, Wu W, Milne C, White T, Barty A, Weierstall U, Panneels V, Nango E, Iwata S, Hunter M, Schapiro I, Schertler G, Neutze R, Standfuss J. Retinal isomerization in bacteriorhodopsin captured by a femtosecond x-ray laser. Science 2018; 361:science.aat0094. [PMID: 29903883 DOI: 10.1126/science.aat0094] [Citation(s) in RCA: 215] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 05/29/2018] [Indexed: 12/23/2022]
Abstract
Ultrafast isomerization of retinal is the primary step in photoresponsive biological functions including vision in humans and ion transport across bacterial membranes. We used an x-ray laser to study the subpicosecond structural dynamics of retinal isomerization in the light-driven proton pump bacteriorhodopsin. A series of structural snapshots with near-atomic spatial resolution and temporal resolution in the femtosecond regime show how the excited all-trans retinal samples conformational states within the protein binding pocket before passing through a twisted geometry and emerging in the 13-cis conformation. Our findings suggest ultrafast collective motions of aspartic acid residues and functional water molecules in the proximity of the retinal Schiff base as a key facet of this stereoselective and efficient photochemical reaction.
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Affiliation(s)
- Przemyslaw Nogly
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Tobias Weinert
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland.,Photon Science Division-Swiss Light Source, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Daniel James
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Sergio Carbajo
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Dmitry Ozerov
- Science IT, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Antonia Furrer
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Dardan Gashi
- SwissFEL, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Veniamin Borin
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Petr Skopintsev
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Kathrin Jaeger
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Karol Nass
- SwissFEL, Paul Scherrer Institut, 5232 Villigen, Switzerland.,Photon Science Division-Swiss Light Source, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Petra Båth
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE- 40530 Gothenburg, Sweden
| | - Robert Bosman
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE- 40530 Gothenburg, Sweden
| | - Jason Koglin
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Matthew Seaberg
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Thomas Lane
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Demet Kekilli
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Steffen Brünle
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Tomoyuki Tanaka
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.,Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe- cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Wenting Wu
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | | | - Thomas White
- Center for Free-Electron Laser Science (CFEL), DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Anton Barty
- Center for Free-Electron Laser Science (CFEL), DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Uwe Weierstall
- Department of Physics, Arizona State University, Tempe, AZ 85287, USA
| | - Valerie Panneels
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Eriko Nango
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.,Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe- cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - So Iwata
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.,Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe- cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Mark Hunter
- Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Igor Schapiro
- Fritz Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Gebhard Schertler
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland.,Department of Biology, ETH Zürich, 8093 Zürich, Switzerland
| | - Richard Neutze
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE- 40530 Gothenburg, Sweden
| | - Jörg Standfuss
- Division of Biology and Chemistry-Laboratory for Biomolecular Research, Paul Scherrer Institut, 5232 Villigen, Switzerland.
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22
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Collette F, Renger T, Müh F, Schmidt am Busch M. Red/Green Color Tuning of Visual Rhodopsins: Electrostatic Theory Provides a Quantitative Explanation. J Phys Chem B 2018; 122:4828-4837. [DOI: 10.1021/acs.jpcb.8b02702] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Florimond Collette
- Institut für Theoretische Physik, Johannes Kepler University Linz, Altenberger Strasse 69, 4040 Linz, Austria
| | - Thomas Renger
- Institut für Theoretische Physik, Johannes Kepler University Linz, Altenberger Strasse 69, 4040 Linz, Austria
| | - Frank Müh
- Institut für Theoretische Physik, Johannes Kepler University Linz, Altenberger Strasse 69, 4040 Linz, Austria
| | - Marcel Schmidt am Busch
- Institut für Theoretische Physik, Johannes Kepler University Linz, Altenberger Strasse 69, 4040 Linz, Austria
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23
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Smitienko OA, Nekrasova OV, Kudriavtsev AV, Yakovleva MA, Shelaev IV, Gostev FE, Dolgikh DA, Kolchugina IB, Nadtochenko VA, Kirpichnikov MP, Feldman TB, Ostrovsky MA. Femtosecond and picosecond dynamics of recombinant bacteriorhodopsin primary reactions compared to the native protein in trimeric and monomeric forms. BIOCHEMISTRY (MOSCOW) 2017; 82:490-500. [DOI: 10.1134/s0006297917040113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Bull JN, Carrascosa E, Scholz MS, Coughlan NJA, Bieske EJ. Online measurement of photoisomerisation efficiency in solution using ion mobility mass spectrometry. Analyst 2017; 142:2100-2103. [DOI: 10.1039/c7an00398f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A new method for probing the photoisomerisation of molecules in solution using ion mobility mass spectrometry is described and demonstrated with a azoheteroarene photoswitch.
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Affiliation(s)
- James N. Bull
- School of Chemistry
- University of Melbourne
- Melbourne
- Australia
| | | | | | | | - Evan J. Bieske
- School of Chemistry
- University of Melbourne
- Melbourne
- Australia
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25
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El-Tahawy MMT, Nenov A, Garavelli M. Photoelectrochromism in the Retinal Protonated Schiff Base Chromophore: Photoisomerization Speed and Selectivity under a Homogeneous Electric Field at Different Operational Regimes. J Chem Theory Comput 2016; 12:4460-75. [DOI: 10.1021/acs.jctc.6b00558] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mohsen M. T. El-Tahawy
- Dipartimento
di Chimica “G. Ciamician″, Universita’ degli Studi di Bologna, Via Selmi, 2 I - 40126 Bologna, Italy
- Chemistry
Department, Faculty of Science, Damanhour University, Damanhour 22511, Egypt
| | - Artur Nenov
- Dipartimento
di Chimica “G. Ciamician″, Universita’ degli Studi di Bologna, Via Selmi, 2 I - 40126 Bologna, Italy
| | - Marco Garavelli
- Dipartimento
di Chimica “G. Ciamician″, Universita’ degli Studi di Bologna, Via Selmi, 2 I - 40126 Bologna, Italy
- Université
de Lyon, Université Claude Bernard Lyon 1, ENS Lyon, Centre
Nationale de Recherche Scientifique, 46 allée d’Italie, 69007 Lyon Cedex 07, France
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26
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Terpugov EL, Degtyareva OV. Photo-induced processes and the reaction dynamics of bacteriorhodopsin. Biophysics (Nagoya-shi) 2015. [DOI: 10.1134/s0006350915020189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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27
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Abstract
Microbial rhodopsins are a diverse group of photoactive transmembrane proteins found in all three domains of life. A member of this protein family, Archaerhodopsin-3 (Arch) of halobacterium Halorubrum sodomense, was recently shown to function as a fluorescent indicator of membrane potential when expressed in mammalian neurons. Arch fluorescence, however, is very dim and is not optimal for applications in live-cell imaging. We used directed evolution to identify mutations that dramatically improve the absolute brightness of Arch, as confirmed biochemically and with live-cell imaging (in Escherichia coli and human embryonic kidney 293 cells). In some fluorescent Arch variants, the pK(a) of the protonated Schiff-base linkage to retinal is near neutral pH, a useful feature for voltage-sensing applications. These bright Arch variants enable labeling of biological membranes in the far-red/infrared and exhibit the furthest red-shifted fluorescence emission thus far reported for a fluorescent protein (maximal excitation/emission at ∼ 620 nm/730 nm).
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28
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Rozin R, Wand A, Jung KH, Ruhman S, Sheves M. pH Dependence of Anabaena Sensory Rhodopsin: Retinal Isomer Composition, Rate of Dark Adaptation, and Photochemistry. J Phys Chem B 2014; 118:8995-9006. [DOI: 10.1021/jp504688y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Rinat Rozin
- Department
of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Amir Wand
- Institute
of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
| | - Kwang-Hwan Jung
- Department
of Life Science and Institute of Biological Interfaces, Sogang University, Shinsu-Dong 1, Mapo-Gu, Seoul 121-742, South Korea
| | - Sanford Ruhman
- Institute
of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
| | - Mordechai Sheves
- Department
of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
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29
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Mehler M, Scholz F, Ullrich SJ, Mao J, Braun M, Brown LJ, Brown RCD, Fiedler SA, Becker-Baldus J, Wachtveitl J, Glaubitz C. The EF loop in green proteorhodopsin affects conformation and photocycle dynamics. Biophys J 2014; 105:385-97. [PMID: 23870260 DOI: 10.1016/j.bpj.2013.06.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 11/20/2022] Open
Abstract
The proteorhodopsin family consists of retinal proteins of marine bacterial origin with optical properties adjusted to their local environments. For green proteorhodopsin, a highly specific mutation in the EF loop, A178R, has been found to cause a surprisingly large redshift of 20 nm despite its distance from the chromophore. Here, we analyze structural and functional consequences of this EF loop mutation by time-resolved optical spectroscopy and solid-state NMR. We found that the primary photoreaction and the formation of the K-like photo intermediate is almost pH-independent and slower compared to the wild-type, whereas the decay of the K-intermediate is accelerated, suggesting structural changes within the counterion complex upon mutation. The photocycle is significantly elongated mainly due to an enlarged lifetime of late photo intermediates. Multidimensional MAS-NMR reveals mutation-induced chemical shift changes propagating from the EF loop to the chromophore binding pocket, whereas dynamic nuclear polarization-enhanced (13)C-double quantum MAS-NMR has been used to probe directly the retinylidene conformation. Our data show a modified interaction network between chromophore, Schiff base, and counterion complex explaining the altered optical and kinetic properties. In particular, the mutation-induced distorted structure in the EF loop weakens interactions, which help reorienting helix F during the reprotonation step explaining the slower photocycle. These data lead to the conclusion that the EF loop plays an important role in proton uptake from the cytoplasm but our data also reveal a clear interaction pathway between the EF loop and retinal binding pocket, which might be an evolutionary conserved communication pathway in retinal proteins.
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Affiliation(s)
- Michaela Mehler
- Institute of Biophysical Chemistry and Centre for Biomolecular Magnetic Resonance, Goethe-University Frankfurt, Germany
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30
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Ernst OP, Lodowski DT, Elstner M, Hegemann P, Brown L, Kandori H. Microbial and animal rhodopsins: structures, functions, and molecular mechanisms. Chem Rev 2014; 114:126-63. [PMID: 24364740 PMCID: PMC3979449 DOI: 10.1021/cr4003769] [Citation(s) in RCA: 746] [Impact Index Per Article: 74.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Indexed: 12/31/2022]
Affiliation(s)
- Oliver P. Ernst
- Departments
of Biochemistry and Molecular Genetics, University of Toronto, 1 King’s College Circle, Medical Sciences Building, Toronto, Ontario M5S 1A8, Canada
| | - David T. Lodowski
- Center
for Proteomics and Bioinformatics, Case
Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Marcus Elstner
- Institute
for Physical Chemistry, Karlsruhe Institute
of Technology, Kaiserstrasse
12, 76131 Karlsruhe, Germany
| | - Peter Hegemann
- Institute
of Biology, Experimental Biophysics, Humboldt-Universität
zu Berlin, Invalidenstrasse
42, 10115 Berlin, Germany
| | - Leonid
S. Brown
- Department
of Physics and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada
| | - Hideki Kandori
- Department
of Frontier Materials, Nagoya Institute
of Technology, Showa-ku, Nagoya 466-8555, Japan
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31
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32
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Kochendoerfer GG, Mathies RA. Ultrafast Spectroscopy of Rhodopsins - Photochemistry at Its Best! Isr J Chem 2013. [DOI: 10.1002/ijch.199500028] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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33
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Cheminal A, Léonard J, Kim S, Jung KH, Kandori H, Haacke S. Steady state emission of the fluorescent intermediate of Anabaena Sensory Rhodopsin as a function of light adaptation conditions. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.09.044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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34
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Alexiev U, Farrens DL. Fluorescence spectroscopy of rhodopsins: insights and approaches. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:694-709. [PMID: 24183695 DOI: 10.1016/j.bbabio.2013.10.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 10/11/2013] [Accepted: 10/16/2013] [Indexed: 01/30/2023]
Abstract
Fluorescence spectroscopy has become an established tool at the interface of biology, chemistry and physics because of its exquisite sensitivity and recent technical advancements. However, rhodopsin proteins present the fluorescence spectroscopist with a unique set of challenges and opportunities due to the presence of the light-sensitive retinal chromophore. This review briefly summarizes some approaches that have successfully met these challenges and the novel insights they have yielded about rhodopsin structure and function. We start with a brief overview of fluorescence fundamentals and experimental methodologies, followed by more specific discussions of technical challenges rhodopsin proteins present to fluorescence studies. Finally, we end by discussing some of the unique insights that have been gained specifically about visual rhodopsin and its interactions with affiliate proteins through the use of fluorescence spectroscopy. This article is part of a Special Issue entitled: Retinal Proteins - You can teach an old dog new tricks.
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Affiliation(s)
- Ulrike Alexiev
- Physics Department, Freie Universität Berlin, Berlin, Germany.
| | - David L Farrens
- Departments of Biochemistry and Molecular Biology, Oregon Health Sciences University, USA
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35
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Ultrafast photochemistry of anabaena sensory rhodopsin: experiment and theory. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:589-97. [PMID: 24099700 DOI: 10.1016/j.bbabio.2013.09.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/28/2013] [Accepted: 09/29/2013] [Indexed: 11/20/2022]
Abstract
Light induced isomerization of the retinal chromophore activates biological function in all retinal protein (RP) driving processes such as ion-pumping, vertebrate vision and phototaxis in organisms as primitive as archea, or as complex as mammals. This process and its consecutive reactions have been the focus of experimental and theoretical research for decades. The aim of this review is to demonstrate how the experimental and theoretical research efforts can now be combined to reach a more comprehensive understanding of the excited state process on the molecular level. Using the Anabaena Sensory Rhodopsin as an example we will show how contemporary time-resolved spectroscopy and recently implemented excited state QM/MM methods consistently describe photochemistry in retinal proteins. This article is part of a Special Issue entitled: Retinal Proteins - You can teach an old dog new tricks.
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36
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Janke C, Scholz F, Becker-Baldus J, Glaubitz C, Wood PG, Bamberg E, Wachtveitl J, Bamann C. Photocycle and vectorial proton transfer in a rhodopsin from the eukaryote Oxyrrhis marina. Biochemistry 2013; 52:2750-63. [PMID: 23586665 DOI: 10.1021/bi301412n] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Retinylidene photoreceptors are ubiquitously present in marine protists as first documented by the identification of green proteorhodopsin (GPR). We present a detailed investigation of a rhodopsin from the protist Oxyrrhis marina (OR1) with respect to its spectroscopic properties and to its vectorial proton transport. Despite its homology to GPR, OR1's features differ markedly in its pH dependence. Protonation of the proton acceptor starts at pH below 4 and is sensitive to the ionic conditions. The mutation of a conserved histidine H62 did not influence the pK(a) value in a similar manner as in other proteorhodopsins where the charged histidine interacts with the proton acceptor forming the so-called His-Asp cluster. Mutational and pH-induced effects were further reflected in the temporal behavior upon light excitation ranging from femtoseconds to seconds. The primary photodynamics exhibits a high sensitivity to the environment of the proton acceptor D100 that are correlated to the different initial states. The mutation of the H62 does not affect photoisomerization at neutral pH. This is in agreement with NMR data indicating the absence of the His-Asp cluster. The subsequent steps in the photocycle revealed protonation reactions at the Schiff base coupled to proton pumping even at low pH. The main electrogenic steps are associated with the reprotonation of the Schiff base and internal proton donor. Hence, OR1 shows a different theme of the His-Asp organization where the low pK(a) of the proton acceptor is not dominated by this interaction, but by other electrostatic factors.
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Affiliation(s)
- Christian Janke
- Max-Planck-Institut für Biophysik, Max-von-Laue Strasse 3, 60438 Frankfurt am Main, Germany
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37
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Aspartate-histidine interaction in the retinal schiff base counterion of the light-driven proton pump of Exiguobacterium sibiricum. Biochemistry 2012; 51:5748-62. [PMID: 22738070 DOI: 10.1021/bi300409m] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One of the distinctive features of eubacterial retinal-based proton pumps, proteorhodopsins, xanthorhodopsin, and others, is hydrogen bonding of the key aspartate residue, the counterion to the retinal Schiff base, to a histidine. We describe properties of the recently found eubacterium proton pump from Exiguobacterium sibiricum (named ESR) expressed in Escherichia coli, especially features that depend on Asp-His interaction, the protonation state of the key aspartate, Asp85, and its ability to accept a proton from the Schiff base during the photocycle. Proton pumping by liposomes and E. coli cells containing ESR occurs in a broad pH range above pH 4.5. Large light-induced pH changes indicate that ESR is a potent proton pump. Replacement of His57 with methionine or asparagine strongly affects the pH-dependent properties of ESR. In the H57M mutant, a dramatic decrease in the quantum yield of chromophore fluorescence emission and a 45 nm blue shift of the absorption maximum with an increase in the pH from 5 to 8 indicate deprotonation of the counterion with a pK(a) of 6.3, which is also the pK(a) at which the M intermediate is observed in the photocycle of the protein solubilized in detergent [dodecyl maltoside (DDM)]. This is in contrast with the case for the wild-type protein, for which the same experiments show that the major fraction of Asp85 is deprotonated at pH >3 and that it protonates only at low pH, with a pK(a) of 2.3. The M intermediate in the wild-type photocycle accumulates only at high pH, with an apparent pK(a) of 9, via deprotonation of a residue interacting with Asp85, presumably His57. In liposomes reconstituted with ESR, the pK(a) values for M formation and spectral shifts are 2-3 pH units lower than in DDM. The distinctively different pH dependencies of the protonation of Asp85 and the accumulation of the M intermediate in the wild-type protein versus the H57M mutant indicate that there is strong Asp-His interaction, which substantially lowers the pK(a) of Asp85 by stabilizing its deprotonated state.
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38
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Herz J, Verhoefen MK, Weber I, Bamann C, Glaubitz C, Wachtveitl J. Critical role of Asp227 in the photocycle of proteorhodopsin. Biochemistry 2012; 51:5589-600. [PMID: 22738119 DOI: 10.1021/bi3003764] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The photocycle of the proton acceptor complex mutant D227N of the bacterial retinal protein proteorhodopsin is investigated employing steady state pH-titration experiments in the UV-visible range as well as femtosecond-pump-probe spectroscopy and flash photolysis in the visible spectral range. The evaluation of the pH-dependent spectra showed that the neutralization of the charge at position 227 has a remarkable influence on the ground state properties of the protein. Both the pK(a) values of the primary proton acceptor and of the Schiff base are considerably decreased. Femtosecond-time-resolved measurements demonstrate that the general S(1) deactivation pathway; that is, the K-state formation is preserved in the D227N mutant. However, the pH-dependence of the reaction rate is lost by the substitution of Asp227 with an asparagine. Also no significant kinetic differences are observed upon deuteration. This is explained by the lack of a strongly hydrogen-bonded water in the vicinity of Asp97, Asp227, and the Schiff base or a change in the hydrogen bonding of it (Ikeda et al. (2007) Biochemistry 46, 5365-5373). The flash photolysis measurements prove a considerably elongated photocycle with pronounced pH-dependence. Interestingly, at pH 9 the M-state is visible until the end of the reaction cycle, leading to the conclusion that the mutation does not only lower the pK(a) of the Schiff base in the unphotolyzed ground state but also prevents an efficient reprotonation reaction.
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Affiliation(s)
- Julia Herz
- Institute of Physical and Theoretical Chemistry, Johann Wolfgang Goethe-University, Max von Laue-Strasse 7, 60438 Frankfurt am Main, Germany
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39
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Scholz F, Bamberg E, Bamann C, Wachtveitl J. Tuning the primary reaction of channelrhodopsin-2 by imidazole, pH, and site-specific mutations. Biophys J 2012; 102:2649-57. [PMID: 22713581 DOI: 10.1016/j.bpj.2012.04.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 03/12/2012] [Accepted: 04/19/2012] [Indexed: 01/11/2023] Open
Abstract
Femtosecond time-resolved absorption measurements were performed to investigate the influence of the pH, imidazole concentration, and point mutations on the isomerization process of Channelrhodopsin-2. Apart from the typical spectral characteristics of retinal isomerization, an additional absorption feature rises for the wild-type (wt) on a timescale from tens of ps to 1 ns within the spectral range of the photoproduct and is attributed to an equilibration between different K-intermediates. Remarkably, this absorption feature vanishes upon addition of imidazole or lowering the pH. In the latter case, the isomerization is dramatically slowed down, due to protonation of negatively charged amino acids within the retinal binding pocket, e.g., E123 and D253. Moreover, we investigated the influence of several point mutations within the retinal binding pocket E123T, E123D, C128T, and D156C. For E123T, the isomerization is retarded compared to wt and E123D, indicating that a negatively charged residue at this position functions as an effective catalyst in the isomerization process. In the case of the C128T mutant, all primary processes are slightly accelerated compared to the wt, whereas the isomerization dynamics for the D156C mutant is similar to wt after addition of imidazole.
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Affiliation(s)
- Frank Scholz
- Institute of Physical and Theoretical Chemistry, Johann Wolfgang Goethe-University, Frankfurt/Main, Germany
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40
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Study of the reactive excited-state dynamics of delipidated bacteriorhodopsin upon surfactant treatments. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2012.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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41
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Wand A, Friedman N, Sheves M, Ruhman S. Ultrafast Photochemistry of Light-Adapted and Dark-Adapted Bacteriorhodopsin: Effects of the Initial Retinal Configuration. J Phys Chem B 2012; 116:10444-52. [DOI: 10.1021/jp2125284] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Amir Wand
- Institute of Chemistry and the
Farkash Center for Light-Induced Processes, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat
Ram, Jerusalem 91904, Israel
| | - Noga Friedman
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Mordechai Sheves
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Sanford Ruhman
- Institute of Chemistry and the
Farkash Center for Light-Induced Processes, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat
Ram, Jerusalem 91904, Israel
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42
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Kim PW, Freer LH, Rockwell NC, Martin SS, Lagarias JC, Larsen DS. Femtosecond Photodynamics of the Red/Green Cyanobacteriochrome NpR6012g4 from Nostoc punctiforme. 1. Forward Dynamics. Biochemistry 2012; 51:608-18. [DOI: 10.1021/bi201507k] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter W. Kim
- Department
of Chemistry and ‡Department of Molecular and Cell Biology, University of California, One Shields Avenue, Davis,
California
95616, United States
| | - Lucy H. Freer
- Department
of Chemistry and ‡Department of Molecular and Cell Biology, University of California, One Shields Avenue, Davis,
California
95616, United States
| | - Nathan C. Rockwell
- Department
of Chemistry and ‡Department of Molecular and Cell Biology, University of California, One Shields Avenue, Davis,
California
95616, United States
| | - Shelley S. Martin
- Department
of Chemistry and ‡Department of Molecular and Cell Biology, University of California, One Shields Avenue, Davis,
California
95616, United States
| | - J. Clark Lagarias
- Department
of Chemistry and ‡Department of Molecular and Cell Biology, University of California, One Shields Avenue, Davis,
California
95616, United States
| | - Delmar S. Larsen
- Department
of Chemistry and ‡Department of Molecular and Cell Biology, University of California, One Shields Avenue, Davis,
California
95616, United States
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43
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Kim PW, Freer LH, Rockwell NC, Martin SS, Lagarias JC, Larsen DS. Femtosecond photodynamics of the red/green cyanobacteriochrome NpR6012g4 from Nostoc punctiforme. 2. reverse dynamics. Biochemistry 2012; 51:619-30. [PMID: 22148731 DOI: 10.1021/bi2017365] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Phytochromes are red/far-red photosensory proteins that utilize photoisomerization of a linear tetrapyrrole (bilin) chromophore to photoconvert reversibly between red- and far-red-absorbing forms (P(r) and P(fr), respectively). Cyanobacteriochromes (CBCRs) are related photosensory proteins with more diverse spectral sensitivity. The mechanisms that underlie this spectral diversity have not yet been fully elucidated. One of the main CBCR subfamilies photoconverts between a red-absorbing 15Z ground state, like the familiar P(r) state of phytochromes, and a green-absorbing photoproduct ((15E)P(g)). We have previously used the red/green CBCR NpR6012g4 from the cyanobacterium Nostoc punctiforme to examine ultrafast photodynamics of the forward photoreaction. Here, we examine the reverse reaction. Using excitation-interleaved transient absorption spectroscopy with broadband detection and multicomponent global analysis, we observed multiphasic excited-state dynamics. Interleaved excitation allowed us to identify wavelength-dependent shifts in the ground-state bleach that equilibrated on a 200 ps time scale, indicating ground-state heterogeneity. Compared to the previously studied forward reaction, the reverse reaction has much faster excited-state decay time constants and significantly higher photoproduct yield. This work thus demonstrates striking differences between the forward and reverse reactions of NpR6012g4 and provides clear evidence of ground-state heterogeneity in the phytochrome superfamily.
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Affiliation(s)
- Peter W Kim
- Department of Chemistry, University of California, Davis, California 95616, United States
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44
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Slouf V, Balashov SP, Lanyi JK, Pullerits T, Polívka T. Carotenoid response to retinal excitation and photoisomerization dynamics in xanthorhodopsin. Chem Phys Lett 2011; 516:96-101. [PMID: 22102759 DOI: 10.1016/j.cplett.2011.09.062] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We present a comparative study of xanthorhodopsin, a proton pump with the carotenoid salinixanthin serving as an antenna, and the closely related bacteriorhodopsin. Upon excitation of retinal, xanthorhodopsin exhibits a wavy transient absorption pattern in the region between 470 and 540 nm. We interpret this signal as due to electrochromic effect of the transient electric field of excited retinal on salinixanthin. The spectral shift decreases during the retinal dynamics through the ultrafast part of the photocycle. Differences in dynamics of bacteriorhodopsin and xanthorhodopsin are discussed.
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Affiliation(s)
- Václav Slouf
- Institute of Physical Biology, University of South Bohemia, Zámek 136, 373 33 Nové Hrady, Czech Republic
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45
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Li X, Chung LW, Morokuma K. Photodynamics of All-trans Retinal Protonated Schiff Base in Bacteriorhodopsin and Methanol Solution. J Chem Theory Comput 2011; 7:2694-8. [DOI: 10.1021/ct200549z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Xin Li
- Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
| | - Lung Wa Chung
- Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
| | - Keiji Morokuma
- Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
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46
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Tsutsui K, Shichida Y. Multiple functions of Schiff base counterion in rhodopsins. Photochem Photobiol Sci 2010; 9:1426-34. [PMID: 20842311 DOI: 10.1039/c0pp00134a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In rhodopsins, visible-light absorption is achieved by the protonation of the chromophore Schiff base. The Schiff base proton is stabilized by the negative charge of an amino acid residue called the Schiff base counterion. Since E113 was identified as the counterion in bovine rhodopsin, there has been growing evidence that the counterion has multiple functions besides proton stabilization. Here, we first introduce generally accepted findings as well as some controversial theories about the identity of the Schiff base counterion in the dark and in intermediate states and then review multiple functions of the counterion in vertebrate visual pigments. Special focus is placed on the recently demonstrated role in photoisomerization efficiency. Finally, differences in the position of the counterion between vertebrate visual pigments and other opsins and its relevance to the molecular evolution of opsins are discussed.
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Affiliation(s)
- Kei Tsutsui
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
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47
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Iyama T, Kawabata H, Tachikawa H. Effects of Point Charges on the Excitation Energies of Protonated Schiff Base of Retinal. ACTA ACUST UNITED AC 2010. [DOI: 10.1080/15533174.2010.486814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Tetsuji Iyama
- a Division of Materials Chemistry, Graduate School of Engineering , Hokkaido University , Sapporo, Japan
| | - Hiroshi Kawabata
- a Division of Materials Chemistry, Graduate School of Engineering , Hokkaido University , Sapporo, Japan
| | - Hiroto Tachikawa
- a Division of Materials Chemistry, Graduate School of Engineering , Hokkaido University , Sapporo, Japan
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48
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Zgrablić G, Ricci M, Novello AM, Parmigiani F. Dependence of Photochemical Reactivity of the All-trans Retinal Protonated Schiff Base on the Solvent and the Excitation Wavelength. Photochem Photobiol 2010; 86:507-12. [DOI: 10.1111/j.1751-1097.2009.00697.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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49
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Imasheva ES, Balashov SP, Choi AR, Jung KH, Lanyi JK. Reconstitution of Gloeobacter violaceus rhodopsin with a light-harvesting carotenoid antenna. Biochemistry 2009; 48:10948-55. [PMID: 19842712 DOI: 10.1021/bi901552x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We show that salinixanthin, the light-harvesting carotenoid antenna of xanthorhodopsin, can be reconstituted into the retinal protein from Gloeobacter violaceus expressed in Escherichia coli. Reconstitution of gloeobacter rhodopsin with the carotenoid is accompanied by characteristic absorption changes and the appearance of CD bands similar to those observed for xanthorhodopsin that indicate immobilization and twist of the carotenoid in the binding site. As in xanthorhodopsin, the carotenoid functions as a light-harvesting antenna. The excitation spectrum for retinal fluorescence emission shows that ca. 36% of the energy absorbed by the carotenoid is transferred to the retinal. From excitation anisotropy, we calculate the angle between the two chromophores as being ca. 50 degrees , similar to that in xanthorhodopsin. The results indicate that gloeobacter rhodopsin binds salinixanthin in a manner similar to that of xanthorhodopsin and suggest that it might bind a carotenoid also in vivo. In the crystallographic structure of xanthorhodopsin, the conjugated chain of the carotenoid lies on the surface of helices E and F, and the 4-keto ring is immersed in the protein at van der Waals distance from the ionone ring of the retinal. The 4-keto ring is in the space occupied by a tryptophan in bacteriorhodopsin, which is replaced by the smaller glycine in xanthorhodopsin and gloeobacter rhodopsin. Specific binding of the carotenoid and its light-harvesting function are eliminated by a single mutation of the gloeobacter protein that replaces this glycine with a tryptophan. This indicates that the 4-keto ring is critically involved in carotenoid binding and suggests that a number of other recently identified retinal proteins, from a diverse group of organisms, could also contain carotenoid antenna since they carry the homologous glycine near the retinal.
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Affiliation(s)
- Eleonora S Imasheva
- Department of Physiology and Biophysics, University of California, Irvine, California 92697, USA
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50
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Theisen M, Linke M, Kerbs M, Fidder H, Madjet MEA, Zacarias A, Heyne K. Femtosecond polarization resolved spectroscopy: A tool for determination of the three-dimensional orientation of electronic transition dipole moments and identification of configurational isomers. J Chem Phys 2009; 131:124511. [DOI: 10.1063/1.3236804] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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