1
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Chrupková P, van Stokkum IHM, Friedrich T, Moldenhauer M, Budisa N, Tseng HW, Polívka T, Cherepanov DA, Maksimov EG, Kloz M. Raman Vibrational Signatures of Excited States of Echinenone in the Orange Carotenoid Protein (OCP) and Implications for its Photoactivation Mechanism. J Mol Biol 2024:168625. [PMID: 38797429 DOI: 10.1016/j.jmb.2024.168625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 05/09/2024] [Accepted: 05/17/2024] [Indexed: 05/29/2024]
Abstract
In this study, the vibrational characteristics of optically excited echinenone in various solvents and the Orange Carotenoid Protein (OCP) in red and orange states are systematically investigated through steady-state and time-resolved spectroscopy techniques. Time-resolved experiments, employing both Transient Absorption (TA) and Femtosecond Stimulated Raman Spectroscopy (FSRS), reveal different states in the OCP photoactivation process. The time-resolved studies indicate vibrational signatures of exited states positioned above the S1 state during the initial 140 fs of carotenoid evolution in OCP, an absence of a vibrational signature for the relaxed S1 state of echinenone in OCP, and more robust signatures of a highly excited ground state (GS) in OCP. Differences in S1 state vibration population signatures between OCP and solvents are attributed to distinct conformations of echinenone in OCP and hydrogen bonds at the keto group forming a short-lived intramolecular charge transfer (ICT) state. The vibrational dynamics of the hot GS in OCP show a more pronounced red shift of ground state CC vibration compared to echinenone in solvents, thus suggesting an unusually hot form of GS. The study proposes a hypothesis for the photoactivation mechanism of OCP, emphasizing the high level of vibrational excitation in longitudinal stretching modes as a driving force. In conclusion, the comparison of vibrational signatures reveals unique dynamics of energy dissipation in OCP, providing insights into the photoactivation mechanism and highlighting the impact of the protein environment on carotenoid behavior. The study underscores the importance of vibrational analysis in understanding the intricate processes involved in early phase OCP photoactivation.
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Affiliation(s)
- Petra Chrupková
- The Extreme Light Infrastructure ERIC, ELI Beamlines Facility, Za Radnicí 835, Dolní Břežany, Czech Republic; University of South Bohemia in České Budějovice, Faculty of Science, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | - Ivo H M van Stokkum
- Vrije Universiteit, Department of Physics and Astronomy, Faculty of Sciences, De Boelelaan 1081, 1081HV Amsterdam, the Netherlands
| | - Thomas Friedrich
- Technische Universität Berlin, Institute of Chemistry PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Marcus Moldenhauer
- Technische Universität Berlin, Institute of Chemistry PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Nediljko Budisa
- University of Manitoba, Department of Chemistry, 144 Dysart Rd, 360 Parker Building, Winnipeg, MB R3T 2N2, Canada
| | - Hsueh-Wei Tseng
- University of Manitoba, Department of Chemistry, 144 Dysart Rd, 360 Parker Building, Winnipeg, MB R3T 2N2, Canada
| | - Tomáš Polívka
- University of South Bohemia in České Budějovice, Faculty of Science, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | - Dmitry A Cherepanov
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 142432 Moscow, Russian Federation; Lomonosov Moscow State University, A.N. Belozersky Institute of Physical-Chemical Biology, 119991 Moscow, Russian Federation
| | - Eugene G Maksimov
- Lomonosov Moscow State University, Faculty of Biology, Vorobyovy Gory 1-12, Moscow 119991, Russian Federation
| | - Miroslav Kloz
- The Extreme Light Infrastructure ERIC, ELI Beamlines Facility, Za Radnicí 835, Dolní Břežany, Czech Republic.
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2
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Beck WF. Intramolecular charge transfer and the function of vibronic excitons in photosynthetic light harvesting. PHOTOSYNTHESIS RESEARCH 2024:10.1007/s11120-024-01095-5. [PMID: 38656684 DOI: 10.1007/s11120-024-01095-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 03/15/2024] [Indexed: 04/26/2024]
Abstract
A widely discussed explanation for the prevalence of pairs or clusters of closely spaced electronic chromophores in photosynthetic light-harvesting proteins is the presence of ultrafast and highly directional excitation energy transfer pathways mediated by vibronic excitons, the delocalized optical excitations derived from mixing of the electronic and vibrational states of the chromophores. We discuss herein the hypothesis that internal conversion processes between exciton states on the <100 fs timescale are possible when the excitonic potential energy surfaces are controlled by the vibrational modes that induce charge transfer character in a strongly coupled system of chromophores. We discuss two examples, the peridinin-chlorophyll protein from marine dinoflagellates and the intact phycobilisome from cyanobacteria, in which the intramolecular charge-transfer (ICT) character arising from out-of-plane distortion of the conjugation of carotenoid or bilin chromophores also results in localization of the initially delocalized optical excitation on the vibrational timescale. Tuning of the ground state conformations of the chromophores to manipulate their ICT character provides a natural photoregulatory mechanism, which would control the overall quantum yield of excitation energy transfer by turning on and off the delocalized character of the optical excitations.
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Affiliation(s)
- Warren F Beck
- Department of Chemistry, Michigan State University, East Lansing, MI, 48824, USA.
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3
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García-Oneto TM, Moyano-Bellido C, Domínguez-Martín MA. Structure and function of the light-protective orange carotenoid protein families. Curr Res Struct Biol 2024; 7:100141. [PMID: 38736459 PMCID: PMC11087925 DOI: 10.1016/j.crstbi.2024.100141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 03/21/2024] [Accepted: 03/29/2024] [Indexed: 05/14/2024] Open
Abstract
Orange carotenoid proteins (OCPs) are unique photoreceptors that are critical for cyanobacterial photoprotection. Upon exposure to blue-green light, OCPs are activated from a stable orange form, OCPO, to an active red form, OCPR, which binds to phycobilisomes (PBSs) and performs photoprotective non-photochemical quenching (NPQ). OCPs can be divided into three main families: the most abundant and best studied OCP1, and two others, OCP2 and OCP3, which have different activation and quenching properties and are yet underexplored. Crystal structures have been acquired for the three OCP clades, providing a glimpse into the conformational underpinnings of their light-absorption and energy dissipation attributes. Recently, the structure of the PBS-OCPR complex has been obtained allowing for an unprecedented insight into the photoprotective action of OCPs. Here, we review the latest findings in the field that have substantially improved our understanding of how cyanobacteria protect themselves from the toxic consequences of excess light absorption. Furthermore, current research is applying the structure of OCPs to bio-inspired optogenetic tools, to function as carotenoid delivery devices, as well as engineering the NPQ mechanism of cyanobacteria to enhance their photosynthetic biomass production.
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Affiliation(s)
| | | | - M. Agustina Domínguez-Martín
- Departamento de Bioquímica y Biología Molecular, Campus de Excelencia Internacional Agroalimentario CeiA3, Universidad de Córdoba, Córdoba, Spain
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4
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Chukhutsina VU, Hutchison CDM, van Thor JJ. The Carbonyl Group in β2 of the Carotenoid Tunes the Photocycle Kinetics in Orange Carotenoid Protein. J Mol Biol 2024; 436:168463. [PMID: 38307159 DOI: 10.1016/j.jmb.2024.168463] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/29/2024] [Accepted: 01/29/2024] [Indexed: 02/04/2024]
Abstract
Adaptation to rapid environmental changes is crucial for maintaining optimal photosynthetic efficiency and is ultimately key to the survival of all photosynthetic organisms. Like most of them, cyanobacteria protect their photosynthetic apparatus against rapidly increasing light intensities by nonphotochemical quenching (NPQ). In cyanobacteria, NPQ is controlled by Orange Carotenoid Protein (OCP) photocycle. OCP is the only known photoreceptor that uses carotenoid for its light activation. How carotenoid drives and controls this unique photoactivation process is still unknown. However, understanding and potentially controlling the OCP photocycle may open up new possibilities for improving photosynthetic biomass. Here we investigate the effect of the carbonyl group in the β2 ring of the carotenoid on the OCP photocycle. We report microsecond to minute OCP light activation kinetics and Arrhenius plots of the two OCP forms: Canthaxanthin-bound OCP (OCPCAN) and echinenone-bound OCP (OCPECH). The difference between the two carotenoids is the presence of a carbonyl group in the β2-ring located in the N-terminal domain of the protein. A combination of temperature-dependent spectroscopy, flash photolysis, and pump-probe transient absorption allows us to report the previously unresolved OCP intermediate associated primarily with the absorption bleach (OCPB). OCPB dominates the photokinetics in the μs to subms time range for OCPCAN and in the μs to ms range for OCPECH. We show that in OCPCAN the OCP photocycle steps are always faster than in OCPECH: from 2 to almost 20 times depending on the step. These results suggest that the presence of the carbonyl group in the β2-ring of the carotenoid accelerates the OCP photocycle.
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Affiliation(s)
- Volha U Chukhutsina
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom.
| | | | - Jasper J van Thor
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom.
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5
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Rose JB, Gascón JA, Sutter M, Sheppard DI, Kerfeld CA, Beck WF. Photoactivation of the orange carotenoid protein requires two light-driven reactions mediated by a metastable monomeric intermediate. Phys Chem Chem Phys 2023; 25:33000-33012. [PMID: 38032096 DOI: 10.1039/d3cp04484j] [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: 12/01/2023]
Abstract
The orange carotenoid protein (OCP) functions as a sensor of the ambient light intensity and as a quencher of bilin excitons when it binds to the core of the cyanobacterial phycobilisome. We show herein that the photoactivation mechanism that converts the resting, orange-colored state, OCPO, to the active red-colored state, OCPR, requires a sequence of two reactions, each requiring absorption of a single photon by an intrinsic ketocarotenoid chromophore. Global analysis of absorption spectra recorded during continuous illumination of OCPO preparations from Synechocystis sp. PCC 6803 detects the reversible formation of a metastable intermediate, OCPI, in which the ketocarotenoid canthaxanthin exhibits an absorption spectrum with a partial red shift and a broadened vibronic structure compared to that of the OCPO state. While the dark recovery from OCPR to OCPI is a first-order, unimolecular reaction, the subsequent conversion of OCPI to the resting OCPO state is bimolecular, involving association of two OCPO monomers to form the dark-stable OCPO dimer aggregate. These results indicate that photodissociation of the OCPO dimer to form the monomeric OCPO intermediate is the first step in the photoactivation mechanism. Formation of the OCPO monomer from the dimer increases the mean value and broadens the distribution of the solvent-accessible surface area of the canthaxanthin chromophore measured in molecular dynamics trajectories at 300 K. The second step in the photoactivation mechanism is initiated by absorption of a second photon, by canthaxanthin in the OCPO monomer, which obtains the fully red-shifted and broadened absorption spectrum detected in the OCPR product state owing to displacement of the C-terminal domain and the translocation of canthaxanthin more than 12 Å into the N-terminal domain. Both steps in the photoactivation reaction of OCP are likely to involve changes in the structure of the C-terminal domain elicited by excited-state conformational motions of the ketocarotenoid.
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Affiliation(s)
- Justin B Rose
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, USA.
| | - José A Gascón
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, USA
| | - Markus Sutter
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824-1322, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Damien I Sheppard
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824-1322, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824-1322, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Warren F Beck
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, USA.
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6
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Tsoraev GV, Bukhanko AY, Mamchur AA, Yaroshevich IA, Sluchanko NN, Tseng HW, Moldenhauer M, Budisa N, Friedrich T, Maksimov EG. Intrinsic tryptophan fluorescence quenching by iodine in non-canonical amino acid reveals alteration of the hydrogen bond network in the photoactive orange carotenoid protein. Biochem Biophys Res Commun 2023; 683:149119. [PMID: 37862781 DOI: 10.1016/j.bbrc.2023.10.051] [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: 10/03/2023] [Accepted: 10/12/2023] [Indexed: 10/22/2023]
Abstract
The Orange Carotenoid Protein (OCP) regulates cyanobacterial photosynthetic activity through photoactivation in intense light. A hydrogen bonding network involving the keto-carotenoid oxygen and Y201 and W288 residues prevents the spontaneous activation of dark-adapted OCP. To investigate the role of the hydrogen bonds in OCP photocycling, we introduced non-canonical amino acids near the keto-carotenoid, particularly iodine at the meta-position of Y201. This modification significantly increased the yield of red OCP photoproducts, albeit with a shorter lifetime. Changes in tryptophan fluorescence during photocycling influenced by the presence of iodine near W288 revealed interactions between Y201 and W288 in the absence of the carotenoid in the C-domain. We propose that upon the relaxation of red states, a ternary complex with the carotenoid is formed. Analysis of spectral signatures and interaction energies indicates that the specific iodo-tyrosine configuration enhances interactions between the carotenoid and W288.
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Affiliation(s)
- Georgy V Tsoraev
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | | | | | | | - Nikolai N Sluchanko
- A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Hsueh-Wei Tseng
- Technical University of Berlin, Institute of Chemistry PC 14, Straße des 17. Juni 135, 10623, Berlin, Germany
| | - Marcus Moldenhauer
- Technical University of Berlin, Institute of Chemistry PC 14, Straße des 17. Juni 135, 10623, Berlin, Germany
| | - Nediljko Budisa
- Department of Chemistry, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Thomas Friedrich
- Technical University of Berlin, Institute of Chemistry PC 14, Straße des 17. Juni 135, 10623, Berlin, Germany
| | - Eugene G Maksimov
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia.
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7
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Arcidiacono A, Accomasso D, Cupellini L, Mennucci B. How orange carotenoid protein controls the excited state dynamics of canthaxanthin. Chem Sci 2023; 14:11158-11169. [PMID: 37860660 PMCID: PMC10583711 DOI: 10.1039/d3sc02662k] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 09/21/2023] [Indexed: 10/21/2023] Open
Abstract
Orange Carotenoid Protein (OCP) is a ketocarotenoid-binding protein essential for photoprotection in cyanobacteria. The main steps of the photoactivated conversion which converts OCP from its resting state to the active one have been extensively investigated. However, the initial photochemical event in the ketocarotenoid which triggers the large structural changes finally leading to the active state is still not understood. Here we employ QM/MM surface hopping nonadiabatic dynamics to investigate the excited-state decay of canthaxanthin in OCP, both in the ultrafast S2 to S1 internal conversion and the slower decay leading back to the ground state. For the former step we show the involvement of an additional excited state, which in the literature has been often named the SX state, and we characterize its nature. For the latter step, we reveal an excited state decay characterized by multiple timescales, which are related to the ground-state conformational heterogeneity of the ketocarotenoid. We assigned the slowly decaying population to the so-called S* state. Finally, we identify a minor decay pathway involving double-bond photoisomerization, which could be the initial trigger to photoactivation of OCP.
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Affiliation(s)
- Amanda Arcidiacono
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa Via G. Moruzzi 13 56124 Pisa Italy
| | - Davide Accomasso
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa Via G. Moruzzi 13 56124 Pisa Italy
| | - Lorenzo Cupellini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa Via G. Moruzzi 13 56124 Pisa Italy
| | - Benedetta Mennucci
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa Via G. Moruzzi 13 56124 Pisa Italy
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8
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Leccese S, Calcinoni A, Wilson A, Kirilovsky D, Carbonera D, Onfroy T, Jolivalt C, Mezzetti A. Orange Carotenoid Protein in Mesoporous Silica: A New System towards the Development of Colorimetric and Fluorescent Sensors for pH and Temperature. MICROMACHINES 2023; 14:1871. [PMID: 37893308 PMCID: PMC10609006 DOI: 10.3390/mi14101871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/26/2023] [Accepted: 09/26/2023] [Indexed: 10/29/2023]
Abstract
Orange carotenoid protein (OCP) is a photochromic carotenoprotein involved in the photoprotection of cyanobacteria. It is activated by blue-green light to a red form OCPR capable of dissipating the excess of energy of the cyanobacterial photosynthetic light-harvesting systems. Activation to OCPR can also be achieved in the dark. In the present work, activation by pH changes of two different OCPs-containing echinenone or canthaxanthin as carotenoids-is investigated in different conditions. A particular emphasis is put on OCP encapsulated in SBA-15 mesoporous silica nanoparticles. It is known that in these hybrid systems, under appropriate conditions, OCP remains photoactive. Here, we show that when immobilised in SBA-15, the OCP visible spectrum is sensitive to pH changes, but such a colorimetric response is very different from the one observed for OCP in solution. In both cases (SBA-15 matrices and solutions), pH-induced colour changes are related either by orange-to-red OCP activation, or by carotenoid loss from the denatured protein. Of particular interest is the response of OCP in SBA-15 matrices, where a sudden change in the Vis absorption spectrum and in colour is observed for pH changing from 2 to 3 (in the case of canthaxanthin-binding OCP in SBA-15: λMAX shifts from 454 to 508 nm) and for pH changing from 3 to 4 (in the case of echinenone-binding OCP in SBA-15: λMAX shifts from 445 to 505 nm). The effect of temperature on OCP absorption spectrum and colour (in SBA-15 matrices) has also been investigated and found to be highly dependent on the properties of the used mesoporous silica matrix. Finally, we also show that simultaneous encapsulation in selected surface-functionalised SBA-15 nanoparticles of appropriate fluorophores makes it possible to develop OCP-based pH-sensitive fluorescent systems. This work therefore represents a proof of principle that OCP immobilised in mesoporous silica is a promising system in the development of colorimetric and fluorometric pH and temperature sensors.
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Affiliation(s)
- Silvia Leccese
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 Place Jussieu, 75005 Paris, France (A.C.); (C.J.)
| | - Andrea Calcinoni
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 Place Jussieu, 75005 Paris, France (A.C.); (C.J.)
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy;
| | - Adjélé Wilson
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, CEDEX, 91198 Gif-sur-Yvette, France (D.K.)
| | - Diana Kirilovsky
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, CEDEX, 91198 Gif-sur-Yvette, France (D.K.)
| | | | - Thomas Onfroy
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 Place Jussieu, 75005 Paris, France (A.C.); (C.J.)
| | - Claude Jolivalt
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 Place Jussieu, 75005 Paris, France (A.C.); (C.J.)
| | - Alberto Mezzetti
- Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 Place Jussieu, 75005 Paris, France (A.C.); (C.J.)
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9
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Du DX, Simjanoska M, Fitzpatrick AWP. Four-dimensional microED of conformational dynamics in protein microcrystals on the femto-to-microsecond timescales. J Struct Biol 2023; 215:107941. [PMID: 36773734 DOI: 10.1016/j.jsb.2023.107941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023]
Abstract
As structural determination of protein complexes approaches atomic resolution, there is an increasing focus on conformational dynamics. Here we conceptualize the combination of two techniques which have become established in recent years: microcrystal electron diffraction and ultrafast electron microscopy. We show that the extremely low dose of pulsed photoemission still enables microED due to the strength of the electron bunching from diffraction of the protein crystals. Indeed, ultrafast electron diffraction experiments on protein crystals have already been demonstrated to be effective in measuring intermolecular forces in protein microcrystals. We discuss difficulties that may arise in the acquisition and processing of data and the overall feasibility of the experiment, paying specific attention to dose and signal-to-noise ratio. In doing so, we outline a detailed workflow that may be effective in minimizing the dose on the specimen. A series of model systems that would be good candidates for initial experiments is provided.
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Affiliation(s)
- Daniel X Du
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th Street, New York, NY 10032, USA
| | - Marija Simjanoska
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th Street, New York, NY 10032, USA
| | - Anthony W P Fitzpatrick
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, 630 West 168th Street, New York, NY 10032, USA.
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10
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Leccese S, Wilson A, Kirilovsky D, Spezia R, Jolivalt C, Mezzetti A. Light-induced infrared difference spectroscopy on three different forms of orange carotenoid protein: focus on carotenoid vibrations. Photochem Photobiol Sci 2023:10.1007/s43630-023-00384-7. [PMID: 36853495 DOI: 10.1007/s43630-023-00384-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 01/27/2023] [Indexed: 03/01/2023]
Abstract
Orange carotenoid protein (OCP) is a photoactive carotenoprotein involved in photoprotection of cyanobacteria, which uses a keto-catorenoid as a chromophore. When it absorbs blue-green light, it converts from an inactive OCPO orange form to an activated OCPR red form, the latter being able to bind the light-harvesting complexes facilitating thermal dissipation of the excess of absorbed light energy. Several research groups have focused their attention on the photoactivation mechanism, characterized by several steps, involving both carotenoid photophysics and protein conformational changes. Among the used techniques, time-resolved IR spectroscopy have the advantage of providing simultaneously information on both the chromophore and the protein, giving thereby the possibility to explore links between carotenoid dynamics and protein dynamics, leading to a better understanding of the mechanism. However, an appropriate interpretation of data requires previous assignment of marker IR bands, for both the carotenoid and the protein. To date, some assignments have concerned specific α-helices of the OCP backbone, but no specific marker band for the carotenoid was identified on solid ground. This paper provides evidence for the assignment of putative marker bands for three carotenoids bound in three different OCPs: 3'-hydroxyechineone (3'-hECN), echinenone (ECN), canthaxanthin (CAN). Light-induced FTIR difference spectra were recorded in H2O and D2O and compared with spectra of isolated carotenoids. The use of DFT calculations allowed to propose a description for the vibrations responsible of several IR bands. Interestingly, most bands are located at the same wavenumber for the three kinds of OCPs suggesting that the conformation of the three carotenoids is the same in the red and in the orange form. These results are discussed in the framework of recent time-resolved IR studies on OCP.
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Affiliation(s)
- Silvia Leccese
- Laboratoire de Réactivité de Surface, LRS, Sorbonne Université, CNRS, 4 Place Jussieu, 75005, Paris, France
| | - Adjélé Wilson
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198, Gif Sur Yvette, France
| | - Diana Kirilovsky
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198, Gif Sur Yvette, France
| | - Riccardo Spezia
- Laboratoire de Chimie Théorique, Sorbonne Université, UMR 7616 CNRS, 4, Place Jussieu, 75005, Paris, France
| | - Claude Jolivalt
- Laboratoire de Réactivité de Surface, LRS, Sorbonne Université, CNRS, 4 Place Jussieu, 75005, Paris, France
| | - Alberto Mezzetti
- Laboratoire de Réactivité de Surface, LRS, Sorbonne Université, CNRS, 4 Place Jussieu, 75005, Paris, France.
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