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Rasmusssen AP, Pedersen HB, Andersen LH. Excited-state dynamics and fluorescence lifetime of cryogenically cooled green fluorescent protein chromophore anions. Phys Chem Chem Phys 2023. [PMID: 38048068 DOI: 10.1039/d3cp04696f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Time-resolved action spectroscopy together with a fs-pump probe scheme is used in an electrostatic ion-storage ring to address lifetimes of specific vibrational levels in electronically excited states. Here we specifically consider the excited-state lifetime of cryogenically cooled green fluorescent protein (GFP) chromophore anions which is systematically measured across the S0-S1 spectral region (450-482 nm). A long lifetime of 5.2 ± 0.3 ns is measured at the S0-S1 band origin. When exciting higher vibrational levels in S1, the lifetime changes dramatically. It decreases by more than two orders of magnitude in a narrow energy region ∼250 cm-1 (31 meV) above the 0-0 transition. This is attributed to the opening of internal conversion over an excited-state energy barrier. The applied experimental technique provides a new way to uncover even small energy barriers, which are crucial for excited-state dynamics.
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Affiliation(s)
- Anne P Rasmusssen
- Department of Physics and Astronomy, Aarhus University, Aarhus 8000, Denmark.
| | - Henrik B Pedersen
- Department of Physics and Astronomy, Aarhus University, Aarhus 8000, Denmark.
| | - Lars H Andersen
- Department of Physics and Astronomy, Aarhus University, Aarhus 8000, Denmark.
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2
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Langeland J, Persen NW, Gruber E, Kiefer HV, Kabylda AM, Bochenkova AV, Andersen LH. Controlling Light-Induced Proton Transfer from the GFP Chromophore. Chemphyschem 2021; 22:833-841. [PMID: 33591586 DOI: 10.1002/cphc.202100068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/16/2021] [Indexed: 01/01/2023]
Abstract
Green Fluorescent Protein (GFP) is known to undergo excited-state proton transfer (ESPT). Formation of a short H-bond favors ultrafast ESPT in GFP-like proteins, such as the GFP S65T/H148D mutant, but the detailed mechanism and its quantum nature remain to be resolved. Here we study in vacuo, light-induced proton transfer from the GFP chromophore in hydrogen-bonded complexes with two anionic proton acceptors, I- and deprotonated trichloroacetic acid (TCA- ). We address the role of the strong H-bond and the quantum mechanical proton-density distribution in the excited state, which determines the proton-transfer probability. Our study shows that chemical modifications to the molecular network drastically change the proton-transfer probability and it can become strongly wavelength dependent. The proton-transfer branching ratio is found to be 60 % for the TCA complex and 10 % for the iodide complex, being highly dependent on the photon energy in the latter case. Using high-level ab initio calculations, we show that light-induced proton transfer takes place in S1 , revealing intrinsic photoacid properties of the isolated GFP chromophore in strongly bound H-bonded complexes. ESPT is found to be very sensitive to the topography of the highly anharmonic potential in S1 , depending on the quantum-density distribution upon vibrational excitation. We also show that the S1 potential-energy surface, and hence excited-state proton transfer, can be controlled by altering the chromophore microenvironment.
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Affiliation(s)
- Jeppe Langeland
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Natascha W Persen
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Elisabeth Gruber
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Hjalte V Kiefer
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Adil M Kabylda
- Department of Chemistry, Lomonosov Moscow State University, 119991, Moscow, Russia
| | | | - Lars H Andersen
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
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3
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Zagorec-Marks W, Foreman MM, Verlet JRR, Weber JM. Probing the Microsolvation Environment of the Green Fluorescent Protein Chromophore In Vacuo. J Phys Chem Lett 2020; 11:1940-1946. [PMID: 32073271 DOI: 10.1021/acs.jpclett.0c00105] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We present vibrational and electronic photodissociation spectra of a model chromophore of the green fluorescent protein in complexes with up to two water molecules, prepared in a cryogenic ion trap at 160-180 K. We find the band origin of the singly hydrated chromophore at 20 985 cm-1 (476.5 nm) and observe partially resolved vibrational signatures. While a single water molecule induces only a small shift of the S1 electronic band of the chromophore, without significant change of the Franck-Condon envelope, the spectrum of the dihydrate shows significant broadening and a greater blue shift of the band edge. Comparison of the vibrational spectra with predicted infrared spectra from density functional theory indicates that water molecules can interact with the oxygen atom on the phenolate group or on the imidazole moiety, respectively.
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Affiliation(s)
- Wyatt Zagorec-Marks
- JILA and Department of Chemistry, University of Colorado, Boulder, Colorado 80309-0440, United States
| | - Madison M Foreman
- JILA and Department of Chemistry, University of Colorado, Boulder, Colorado 80309-0440, United States
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, U.K
| | - J Mathias Weber
- JILA and Department of Chemistry, University of Colorado, Boulder, Colorado 80309-0440, United States
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4
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Singh TP, Devi TJ, Singh NP, Singh OM. GFP Chromophores from L‐Phenylalanine: Synthesis, Photophysical and Thermal Properties. ChemistrySelect 2018. [DOI: 10.1002/slct.201801288] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Langeland J, Kjær C, Andersen LH, Brøndsted Nielsen S. The Effect of an Electric Field on the Spectroscopic Properties of the Isolated Green Fluorescent Protein Chromophore Anion. Chemphyschem 2018; 19:1686-1690. [DOI: 10.1002/cphc.201800225] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Jeppe Langeland
- Department of Physics and AstronomyAarhus University Denmark
| | - Christina Kjær
- Department of Physics and AstronomyAarhus University Denmark
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McLaughlin C, Assmann M, Parkes MA, Woodhouse JL, Lewin R, Hailes HC, Worth GA, Fielding HH. ortho and para chromophores of green fluorescent protein: controlling electron emission and internal conversion. Chem Sci 2017; 8:1621-1630. [PMID: 29780449 PMCID: PMC5933426 DOI: 10.1039/c6sc03833f] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/05/2016] [Indexed: 12/22/2022] Open
Abstract
Green fluorescent protein (GFP) continues to play an important role in the biological and biochemical sciences as an efficient fluorescent probe and is also known to undergo light-induced redox transformations. Here, we employ photoelectron spectroscopy and quantum chemistry calculations to investigate how the phenoxide moiety controls the competition between electron emission and internal conversion in the isolated GFP chromophore anion, following photoexcitation with ultraviolet light in the range 400-230 nm. We find that moving the phenoxide group from the para position to the ortho position enhances internal conversion back to the ground electronic state but that adding an additional OH group to the para chromophore, at the ortho position, impedes internal conversion. Guided by quantum chemistry calculations, we interpret these observations in terms of torsions around the C-C-C bridge being enhanced by electrostatic repulsions or impeded by the formation of a hydrogen-bonded seven-membered ring. We also find that moving the phenoxide group from the para position to the ortho position reduces the energy required for detachment processes, whereas adding an additional OH group to the para chromophore at the ortho position increases the energy required for detachment processes. These results have potential applications in tuning light-induced redox processes of this biologically and technologically important fluorescent protein.
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Affiliation(s)
- Conor McLaughlin
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , UK .
| | - Mariana Assmann
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , UK .
| | - Michael A Parkes
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , UK .
| | - Joanne L Woodhouse
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , UK .
| | - Ross Lewin
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , UK .
| | - Helen C Hailes
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , UK .
| | - Graham A Worth
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , UK .
| | - Helen H Fielding
- Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , UK .
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Stockett MH, Boesen M, Houmøller J, Brøndsted Nielsen S. Accessing the Intrinsic Nature of Electronic Transitions from Gas‐Phase Spectroscopy of Molecular Ion/Zwitterion Complexes. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | - Mikkel Boesen
- Department of Physics and Astronomy Aarhus University Denmark
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8
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Stockett MH, Boesen M, Houmøller J, Brøndsted Nielsen S. Accessing the Intrinsic Nature of Electronic Transitions from Gas‐Phase Spectroscopy of Molecular Ion/Zwitterion Complexes. Angew Chem Int Ed Engl 2017; 56:3490-3495. [DOI: 10.1002/anie.201611320] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Indexed: 11/07/2022]
Affiliation(s)
| | - Mikkel Boesen
- Department of Physics and Astronomy Aarhus University Denmark
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Andersen LH, Bochenkova AV, Houmøller J, Kiefer HV, Lattouf E, Stockett MH. A PYP chromophore acts as a 'photoacid' in an isolated hydrogen bonded complex. Phys Chem Chem Phys 2016; 18:9909-13. [PMID: 27009407 DOI: 10.1039/c6cp00433d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The light-induced response of a neutral Photoactive Yellow Protein chromophore in a hydrogen-bonded complex with a proton acceptor has been studied by dual-detection action absorption spectroscopy and density functional theory. We show that the chromophore is a 'photoacid' and that ultrafast excited-state proton transfer might be operative in an isolated complex.
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Affiliation(s)
- Lars H Andersen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark.
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