1
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Salvadori G, Mazzeo P, Accomasso D, Cupellini L, Mennucci B. Deciphering Photoreceptors Through Atomistic Modeling from Light Absorption to Conformational Response. J Mol Biol 2024; 436:168358. [PMID: 37944793 DOI: 10.1016/j.jmb.2023.168358] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/28/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023]
Abstract
In this review, we discuss the successes and challenges of the atomistic modeling of photoreceptors. Throughout our presentation, we integrate explanations of the primary methodological approaches, ranging from quantum mechanical descriptions to classical enhanced sampling methods, all while providing illustrative examples of their practical application to specific systems. To enhance the effectiveness of our analysis, our primary focus has been directed towards the examination of applications across three distinct photoreceptors. These include an example of Blue Light-Using Flavin (BLUF) domains, a bacteriophytochrome, and the orange carotenoid protein (OCP) employed by cyanobacteria for photoprotection. Particular emphasis will be placed on the pivotal role played by the protein matrix in fine-tuning the initial photochemical event within the embedded chromophore. Furthermore, we will investigate how this localized perturbation initiates a cascade of events propagating from the binding pocket throughout the entire protein structure, thanks to the intricate network of interactions between the chromophore and the protein.
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Affiliation(s)
- Giacomo Salvadori
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Patrizia Mazzeo
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Davide Accomasso
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Lorenzo Cupellini
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Benedetta Mennucci
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
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2
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Fadini A, Hutchison CDM, Morozov D, Chang J, Maghlaoui K, Perrett S, Luo F, Kho JCX, Romei MG, Morgan RML, Orr CM, Cordon-Preciado V, Fujiwara T, Nuemket N, Tosha T, Tanaka R, Owada S, Tono K, Iwata S, Boxer SG, Groenhof G, Nango E, van Thor JJ. Serial Femtosecond Crystallography Reveals that Photoactivation in a Fluorescent Protein Proceeds via the Hula Twist Mechanism. J Am Chem Soc 2023. [PMID: 37418747 PMCID: PMC10375524 DOI: 10.1021/jacs.3c02313] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2023]
Abstract
Chromophore cis/trans photoisomerization is a fundamental process in chemistry and in the activation of many photosensitive proteins. A major task is understanding the effect of the protein environment on the efficiency and direction of this reaction compared to what is observed in the gas and solution phases. In this study, we set out to visualize the hula twist (HT) mechanism in a fluorescent protein, which is hypothesized to be the preferred mechanism in a spatially constrained binding pocket. We use a chlorine substituent to break the twofold symmetry of the embedded phenolic group of the chromophore and unambiguously identify the HT primary photoproduct. Through serial femtosecond crystallography, we then track the photoreaction from femtoseconds to the microsecond regime. We observe signals for the photoisomerization of the chromophore as early as 300 fs, obtaining the first experimental structural evidence of the HT mechanism in a protein on its femtosecond-to-picosecond timescale. We are then able to follow how chromophore isomerization and twisting lead to secondary structure rearrangements of the protein β-barrel across the time window of our measurements.
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Affiliation(s)
- Alisia Fadini
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, U.K
| | - Christopher D M Hutchison
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, U.K
| | - Dmitry Morozov
- Nanoscience Center and Department of Chemistry, University of Jyväskylä, Jyväskylä 40014, Finland
| | - Jeffrey Chang
- Department of Physics, Stanford University, Stanford, California 94305, United States
| | - Karim Maghlaoui
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, U.K
| | - Samuel Perrett
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, U.K
| | - Fangjia Luo
- RIKEN Spring-8 Center, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5148, Japan
| | - Jeslyn C X Kho
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, U.K
| | - Matthew G Romei
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - R Marc L Morgan
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, U.K
| | - Christian M Orr
- Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot OX11 0DE, U.K
| | - Violeta Cordon-Preciado
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, U.K
| | - Takaaki Fujiwara
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, Miyagi 980-8577, Japan
| | - Nipawan Nuemket
- RIKEN Spring-8 Center, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5148, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo, Kyoto 606-8501, Japan
| | - Takehiko Tosha
- RIKEN Spring-8 Center, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5148, Japan
| | - Rie Tanaka
- RIKEN Spring-8 Center, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5148, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo, Kyoto 606-8501, Japan
| | - Shigeki Owada
- RIKEN Spring-8 Center, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5198, Japan
| | - Kensuke Tono
- RIKEN Spring-8 Center, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5198, Japan
| | - So Iwata
- RIKEN Spring-8 Center, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5148, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo, Kyoto 606-8501, Japan
| | - Steven G Boxer
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Gerrit Groenhof
- Nanoscience Center and Department of Chemistry, University of Jyväskylä, Jyväskylä 40014, Finland
| | - Eriko Nango
- RIKEN Spring-8 Center, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5148, Japan
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, Miyagi 980-8577, Japan
| | - Jasper J van Thor
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, U.K
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3
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Pu R, Wang Z, Zhu R, Jiang J, Weng TC, Huang Y, Liu W. Investigation of Ultrafast Configurational Photoisomerization of Bilirubin Using Femtosecond Stimulated Raman Spectroscopy. J Phys Chem Lett 2023; 14:809-816. [PMID: 36655842 DOI: 10.1021/acs.jpclett.2c03535] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Phototherapy is an efficient and safe way to reduce high levels of free 4Z,15Z-bilirubin (ZZ-BR) in the serum of newborns. The success of BR phototherapy lies in photoinduced configurational and structural isomerization processes that form excretable isomers. However, the physical picture of photoinduced photoisomerization of ZZ-BR is still unclear. Here, we strategically implement tunable femtosecond stimulated Raman spectroscopy and several time-resolved electronic spectroscopies, assisted by quantum chemical calculations, to dissect the detailed primary configurational isomerization dynamics of free ZZ-BR in organic solvents. The results of this study demonstrate that upon photoexcitation, ultrafast configurational isomerization proceeds by a volume-conserving "hula twist", followed by intramolecular hydrogen-bond distortion and large-scale rotation of the two dipyrrinone halves of the ZZ-BR isomer in a few picoseconds. After that, most of the population recovers back to ZZ-BR, and a very small amount is converted into stable BR isomers via structural isomerization.
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Affiliation(s)
- Ruihua Pu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- STU and SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
| | - Ziyu Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- STU and SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
| | - Ruixue Zhu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jiaming Jiang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Tsu-Chien Weng
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yifan Huang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Weimin Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- STU and SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
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4
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Wang Z, Zhang Y, Chen C, Zhu R, Jiang J, Weng TC, Ji Q, Huang Y, Fang C, Liu W. Mapping the Complete Photocycle that Powers a Large Stokes Shift Red Fluorescent Protein. Angew Chem Int Ed Engl 2023; 62:e202212209. [PMID: 36440527 DOI: 10.1002/anie.202212209] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 11/29/2022]
Abstract
Large Stokes shift (LSS) red fluorescent proteins (RFPs) are highly desirable for bioimaging advances. The RFP mKeima, with coexisting cis- and trans-isomers, holds significance as an archetypal system for LSS emission due to excited-state proton transfer (ESPT), yet the mechanisms remain elusive. We implemented femtosecond stimulated Raman spectroscopy (FSRS) and various time-resolved electronic spectroscopies, aided by quantum calculations, to dissect the cis- and trans-mKeima photocycle from ESPT, isomerization, to ground-state proton transfer in solution. This work manifests the power of FSRS with global analysis to resolve Raman fingerprints of intermediate states. Importantly, the deprotonated trans-isomer governs LSS emission at 620 nm, while the deprotonated cis-isomer's 520 nm emission is weak due to an ultrafast cis-to-trans isomerization. Complementary spectroscopic techniques as a table-top toolset are thus essential to study photochemistry in physiological environments.
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Affiliation(s)
- Ziyu Wang
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Ya Zhang
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Cheng Chen
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, 97331, Corvallis, OR, USA
| | - Ruixue Zhu
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Jiaming Jiang
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Tsu-Chien Weng
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Quanjiang Ji
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Yifan Huang
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, 97331, Corvallis, OR, USA
| | - Weimin Liu
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
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5
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Boeije Y, Olivucci M. From a one-mode to a multi-mode understanding of conical intersection mediated ultrafast organic photochemical reactions. Chem Soc Rev 2023; 52:2643-2687. [PMID: 36970950 DOI: 10.1039/d2cs00719c] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
This review discusses how ultrafast organic photochemical reactions are controlled by conical intersections, highlighting that decay to the ground-state at multiple points of the intersection space results in their multi-mode character.
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Affiliation(s)
- Yorrick Boeije
- Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Massimo Olivucci
- Chemistry Department, University of Siena, Via Aldo Moro n. 2, 53100 Siena, Italy
- Chemistry Department, Bowling Green State University, Overman Hall, Bowling Green, Ohio 43403, USA
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6
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Kochman MA, Palczewski K, Kubas A. Theoretical Study of the Photoisomerization Mechanism of All- Trans-Retinyl Acetate. J Phys Chem A 2021; 125:8358-8372. [PMID: 34546761 PMCID: PMC8488936 DOI: 10.1021/acs.jpca.1c05533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
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The compound 9-cis-retinyl acetate (9-cis-RAc) is a precursor
to 9-cis-retinal,
which has potential application in the treatment of some hereditary
diseases of the retina. An attractive synthetic route to 9-cis-RAc is based on the photoisomerization reaction of the
readily available all-trans-RAc. In the present study,
we examine the mechanism of the photoisomerization reaction with the
use of state-of-the-art electronic structure calculations for two
polyenic model compounds: tEtEt-octatetraene and tEtEtEc-2,6-dimethyl-1,3,5,7,9-decapentaene. The occurrence
of photoisomerization is attributed to a chain-kinking mechanism,
whereby a series of S1/S0 conical intersections
associated with kinking deformations at different positions along
the polyenic chain mediate internal conversion to the S0 state, and subsequent isomerization around one of the double bonds.
Two other possible photoisomerization mechanisms are taken into account,
but they are rejected as incompatible with simulation results and/or
the available spectroscopic data.
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Affiliation(s)
- Michał Andrzej Kochman
- Institute of Physical Chemistry, Polish Academy of Sciences, Ul. Marcina Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Krzysztof Palczewski
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, California 92697, United States.,Department of Physiology and Biophysics, University of California, Irvine, California 92697, United States.,Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Adam Kubas
- Institute of Physical Chemistry, Polish Academy of Sciences, Ul. Marcina Kasprzaka 44/52, 01-224 Warszawa, Poland
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7
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Mai S, González L. Molecular Photochemistry: Recent Developments in Theory. Angew Chem Int Ed Engl 2020; 59:16832-16846. [PMID: 32052547 PMCID: PMC7540682 DOI: 10.1002/anie.201916381] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/12/2020] [Indexed: 12/16/2022]
Abstract
Photochemistry is a fascinating branch of chemistry that is concerned with molecules and light. However, the importance of simulating light-induced processes is reflected also in fields as diverse as biology, material science, and medicine. This Minireview highlights recent progress achieved in theoretical chemistry to calculate electronically excited states of molecules and simulate their photoinduced dynamics, with the aim of reaching experimental accuracy. We focus on emergent methods and give selected examples that illustrate the progress in recent years towards predicting complex electronic structures with strong correlation, calculations on large molecules, describing multichromophoric systems, and simulating non-adiabatic molecular dynamics over long time scales, for molecules in the gas phase or in complex biological environments.
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Affiliation(s)
- Sebastian Mai
- Photonics InstituteVienna University of TechnologyGusshausstrasse 27–291040ViennaAustria
| | - Leticia González
- Institute of Theoretical ChemistryFaculty of ChemistryUniversity of ViennaWähringer Strasse 171090ViennaAustria
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8
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Mai S, González L. Molekulare Photochemie: Moderne Entwicklungen in der theoretischen Chemie. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201916381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Sebastian Mai
- Institut für Photonik Technische Universität Wien Gußhausstraße 27–29 1040 Wien Österreich
| | - Leticia González
- Institut für theoretische Chemie Fakultät für Chemie Universität Wien Währinger Straße 17 1090 Wien Österreich
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9
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Xie B, Fang W. Combined Quantum Trajectory Mean‐Field and Molecular Mechanical (QTMF/MM) Nonadiabatic Dynamics Simulations on the Photoinduced Ring‐Opening Reaction of 2(5H)‐Thiophenone. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201900076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Bin‐Bin Xie
- Hangzhou Institute of Advanced StudiesZhejiang Normal University 1108 Gengwen Road Hangzhou 311231, Zhejiang P. R. China
| | - Wei‐Hai Fang
- Hangzhou Institute of Advanced StudiesZhejiang Normal University 1108 Gengwen Road Hangzhou 311231, Zhejiang P. R. China
- Key Laboratory of Theoretical and Computational Photochemistry Ministry of Education College of ChemistryBeijing Normal University Beijing 100875 P. R. China
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10
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Wu D, Guo WW, Liu XY, Cui G. Excited-State Intramolecular Proton Transfer in a Blue Fluorescence Chromophore Induces Dual Emission. Chemphyschem 2016; 17:2340-7. [DOI: 10.1002/cphc.201600386] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Indexed: 01/15/2023]
Affiliation(s)
- Dan Wu
- Key Laboratory of Theoretical and Computational Photochemistry; Ministry of Education; College of Chemistry; Beijing Normal University; Beijing 100875 China
| | - Wei-Wei Guo
- Key Laboratory of Theoretical and Computational Photochemistry; Ministry of Education; College of Chemistry; Beijing Normal University; Beijing 100875 China
| | - Xiang-Yang Liu
- Key Laboratory of Theoretical and Computational Photochemistry; Ministry of Education; College of Chemistry; Beijing Normal University; Beijing 100875 China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry; Ministry of Education; College of Chemistry; Beijing Normal University; Beijing 100875 China
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11
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Armengol P, Gelabert R, Moreno M, Lluch JM. Theoretical Computer-Aided Mutagenic Study on the Triple Green Fluorescent Protein Mutant S65T/H148D/Y145F. Chemphyschem 2015; 16:2134-9. [PMID: 25916771 DOI: 10.1002/cphc.201500158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 03/27/2015] [Indexed: 11/07/2022]
Abstract
Green fluorescent protein (GFP) mutant S65T/H148D has been proposed to host a photocycle that involves an excited-state proton transfer between the chromophore (Cro) and the Asp148 residue and takes place in less than 50 fs without a measurable kinetic isotope effect. It has been suggested that the interaction between the unsuspected Tyr145 residue and the chromophore is needed for the ultrafast sub-50 fs rise in fluorescence. To verify this, we have performed a computer-aided mutagenic study to introduce the additional mutation Y145F, which eliminates this interaction. By means of QM/MM molecular dynamics simulations and time-dependent density functional theory studies, we have assessed the importance of the Cro-Tyr145 interaction and the solvation of Asp148 and shown that in the triple mutant S65T/H148D/Y145F a significant loss in the ultrafast rise of the Stokes-shifted fluorescence should be expected.
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Affiliation(s)
- Pau Armengol
- Department de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)
| | - Ricard Gelabert
- Department de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain).
| | - Miquel Moreno
- Department de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)
| | - José M Lluch
- Department de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain).,Institut de Bioquímica i de Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)
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12
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Laptenok SP, Lukacs A, Gil A, Brust R, Sazanovich IV, Greetham GM, Tonge PJ, Meech SR. Complete Proton Transfer Cycle in GFP and Its T203V and S205V Mutants. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201503672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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13
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Laptenok SP, Lukacs A, Gil A, Brust R, Sazanovich IV, Greetham GM, Tonge PJ, Meech SR. Complete Proton Transfer Cycle in GFP and Its T203V and S205V Mutants. Angew Chem Int Ed Engl 2015; 54:9303-7. [PMID: 26087935 PMCID: PMC4576823 DOI: 10.1002/anie.201503672] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Indexed: 11/17/2022]
Abstract
Proton transfer is critical in many important biochemical reactions. The unique three-step excited-state proton transfer in avGFP allows observations of protein proton transport in real-time. In this work we exploit femtosecond to microsecond transient IR spectroscopy to record, in D2O, the complete proton transfer photocycle of avGFP, and two mutants (T203V and S205V) which modify the structure of the proton wire. Striking differences and similarities are observed among the three mutants yielding novel information on proton transfer mechanism, rates, isotope effects, H-bond strength and proton wire stability. These data provide a detailed picture of the dynamics of long-range proton transfer in a protein against which calculations may be compared.
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Affiliation(s)
- Sergey P Laptenok
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ (UK)
| | - Andras Lukacs
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ (UK).,Department of Biophysics, Medical School, Szigeti str. 12, 7624 Pécs (Hungary)
| | - Agnieszka Gil
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400 (USA)
| | - Richard Brust
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400 (USA).,The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458 (USA)
| | - Igor V Sazanovich
- Central Laser Facility, Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxon OX11 0QX (UK)
| | - Gregory M Greetham
- Central Laser Facility, Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxon OX11 0QX (UK)
| | - Peter J Tonge
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400 (USA).
| | - Stephen R Meech
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ (UK).
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