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Guo Y, He L, Ding Y, Kloo L, Pantazis DA, Messinger J, Sun L. Closing Kok's cycle of nature's water oxidation catalysis. Nat Commun 2024; 15:5982. [PMID: 39013902 PMCID: PMC11252165 DOI: 10.1038/s41467-024-50210-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 07/03/2024] [Indexed: 07/18/2024] Open
Abstract
The Mn4CaO5(6) cluster in photosystem II catalyzes water splitting through the Si state cycle (i = 0-4). Molecular O2 is formed and the natural catalyst is reset during the final S3 → (S4) → S0 transition. Only recently experimental breakthroughs have emerged for this transition but without explicit information on the S0-state reconstitution, thus the progression after O2 release remains elusive. In this report, our molecular dynamics simulations combined with density functional calculations suggest a likely missing link for closing the cycle, i.e., restoring the first catalytic state. Specifically, the formation of closed-cubane intermediates with all hexa-coordinate Mn is observed, which would undergo proton release, water dissociation, and ligand transfer to produce the open-cubane structure of the S0 state. Thereby, we theoretically identify the previously unknown structural isomerism in the S0 state that acts as the origin of the proposed structural flexibility prevailing in the cycle, which may be functionally important for nature's water oxidation catalysis.
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Affiliation(s)
- Yu Guo
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, China
| | - Lanlan He
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, China
| | - Yunxuan Ding
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, China
| | - Lars Kloo
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-10044, Stockholm, Sweden
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
| | - Johannes Messinger
- Department of Plant Physiology, Umeå University, Linnaeus väg 6 (KBC huset), SE-90187, Umeå, Sweden
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University, SE-75120, Uppsala, Sweden
| | - Licheng Sun
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China.
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, China.
- Division of Solar Energy Conversion and Catalysis at Westlake University, Zhejiang Baima Lake Laboratory Co., Ltd., Hangzhou, 310000, Zhejiang, China.
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2
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Krysiak S, Burda K. The Effect of Removal of External Proteins PsbO, PsbP and PsbQ on Flash-Induced Molecular Oxygen Evolution and Its Biphasicity in Tobacco PSII. Curr Issues Mol Biol 2024; 46:7187-7218. [PMID: 39057069 PMCID: PMC11276211 DOI: 10.3390/cimb46070428] [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: 06/02/2024] [Revised: 06/30/2024] [Accepted: 07/02/2024] [Indexed: 07/28/2024] Open
Abstract
The oxygen evolution within photosystem II (PSII) is one of the most enigmatic processes occurring in nature. It is suggested that external proteins surrounding the oxygen-evolving complex (OEC) not only stabilize it and provide an appropriate ionic environment but also create water channels, which could be involved in triggering the ingress of water and the removal of O2 and protons outside the system. To investigate the influence of these proteins on the rate of oxygen release and the efficiency of OEC function, we developed a measurement protocol for the direct measurement of the kinetics of oxygen release from PSII using a Joliot-type electrode. PSII-enriched tobacco thylakoids were used in the experiments. The results revealed the existence of slow and fast modes of oxygen evolution. This observation is model-independent and requires no specific assumptions about the initial distribution of the OEC states. The gradual removal of exogenous proteins resulted in a slowdown of the rapid phase (~ms) of O2 release and its gradual disappearance while the slow phase (~tens of ms) accelerated. The role of external proteins in regulating the biphasicity and efficiency of oxygen release is discussed based on observed phenomena and current knowledge.
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Affiliation(s)
| | - Kvetoslava Burda
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, al. Mickiewicza 30, 30-059 Krakow, Poland;
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3
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Yano J, Kern J, Yachandra VK. Structure Function Studies of Photosystem II Using X-Ray Free Electron Lasers. Annu Rev Biophys 2024; 53:343-365. [PMID: 39013027 DOI: 10.1146/annurev-biophys-071723-102519] [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] [Indexed: 07/18/2024]
Abstract
The structure and mechanism of the water-oxidation chemistry that occurs in photosystem II have been subjects of great interest. The advent of X-ray free electron lasers allowed the determination of structures of the stable intermediate states and of steps in the transitions between these intermediate states, bringing a new perspective to this field. The room-temperature structures collected as the photosynthetic water oxidation reaction proceeds in real time have provided important novel insights into the structural changes and the mechanism of the water oxidation reaction. The time-resolved measurements have also given us a view of how this reaction-which involves multielectron, multiproton processes-is facilitated by the interaction of the ligands and the protein residues in the oxygen-evolving complex. These structures have also provided a picture of the dynamics occurring in the channels within photosystem II that are involved in the transport of the substrate water to the catalytic center and protons to the bulk.
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Affiliation(s)
- Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA; , ,
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA; , ,
| | - Vittal K Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA; , ,
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4
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Liu J, Yang KR, Long Z, Armstrong WH, Brudvig GW, Batista VS. Water Ligands Regulate the Redox Leveling Mechanism of the Oxygen-Evolving Complex of the Photosystem II. J Am Chem Soc 2024; 146:15986-15999. [PMID: 38833517 DOI: 10.1021/jacs.4c02926] [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: 06/06/2024]
Abstract
Understanding how water ligands regulate the conformational changes and functionality of the oxygen-evolving complex (OEC) in photosystem II (PSII) throughout the catalytic cycle of oxygen evolution remains a highly intriguing and unresolved challenge. In this study, we investigate the effect of water insertion (WI) on the redox state of the OEC by using the molecular dynamics (MD) and quantum mechanics/molecular mechanics (QM/MM) hybrid methods. We find that water binding significantly reduces the free energy change for proton-coupled electron transfer (PCET) from Mn to YZ•, underscoring the important regulatory role of water binding, which is essential for enabling the OEC redox-leveling mechanism along the catalytic cycle. We propose a water binding mechanism in which WI is thermodynamically favored by the closed-cubane form of the OEC, with water delivery mediated by Ca2+ ligand exchange. Isomerization from the closed- to open-cubane conformation at three post-WI states highlights the importance of the location of the MnIII center in the OEC and the orientation of its Jahn-Teller axis to conformational changes of the OEC, which might be critical for the formation of the O-O bond. These findings reveal a complex interplay between conformational changes in the OEC and the ligand environment during the activation of the OEC by YZ•. Analogous regulatory effects due to water ligand binding are expected to be important for a wide range of catalysts activated by redox state transitions in aqueous environments.
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Affiliation(s)
- Jinchan Liu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Ke R Yang
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin 300071, China
| | - Zhuoran Long
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - William H Armstrong
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Gary W Brudvig
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, United States
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
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5
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Chernev P, Aydin AO, Messinger J. On the simulation and interpretation of substrate-water exchange experiments in photosynthetic water oxidation. PHOTOSYNTHESIS RESEARCH 2024:10.1007/s11120-024-01084-8. [PMID: 38512410 DOI: 10.1007/s11120-024-01084-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/01/2024] [Indexed: 03/23/2024]
Abstract
Water oxidation by photosystem II (PSII) sustains most life on Earth, but the molecular mechanism of this unique process remains controversial. The ongoing identification of the binding sites and modes of the two water-derived substrate oxygens ('substrate waters') in the various intermediates (Si states, i = 0, 1, 2, 3, 4) that the water-splitting tetra-manganese calcium penta-oxygen (Mn4CaO5) cluster attains during the reaction cycle provides central information towards resolving the unique chemistry of biological water oxidation. Mass spectrometric measurements of single- and double-labeled dioxygen species after various incubation times of PSII with H218O provide insight into the substrate binding modes and sites via determination of exchange rates. Such experiments have revealed that the two substrate waters exchange with different rates that vary independently with the Si state and are hence referred to as the fast (Wf) and the slow (WS) substrate waters. New insight for the molecular interpretation of these rates arises from our recent finding that in the S2 state, under special experimental conditions, two different rates of WS exchange are observed that appear to correlate with the high spin and low spin conformations of the Mn4CaO5 cluster. Here, we reexamine and unite various proposed methods for extracting and assigning rate constants from this recent data set. The analysis results in a molecular model for substrate-water binding and exchange that reconciles the expected non-exchangeability of the central oxo bridge O5 when located between two Mn(IV) ions with the experimental and theoretical assignment of O5 as WS in all S states. The analysis also excludes other published proposals for explaining the water exchange kinetics.
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Affiliation(s)
- Petko Chernev
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, 75120, Uppsala, Sweden
| | - A Orkun Aydin
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, 75120, Uppsala, Sweden
| | - Johannes Messinger
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, 75120, Uppsala, Sweden.
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6
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de Lichtenberg C, Rapatskiy L, Reus M, Heyno E, Schnegg A, Nowaczyk MM, Lubitz W, Messinger J, Cox N. Assignment of the slowly exchanging substrate water of nature's water-splitting cofactor. Proc Natl Acad Sci U S A 2024; 121:e2319374121. [PMID: 38437550 PMCID: PMC10945779 DOI: 10.1073/pnas.2319374121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/12/2024] [Indexed: 03/06/2024] Open
Abstract
Identifying the two substrate water sites of nature's water-splitting cofactor (Mn4CaO5 cluster) provides important information toward resolving the mechanism of O-O bond formation in Photosystem II (PSII). To this end, we have performed parallel substrate water exchange experiments in the S1 state of native Ca-PSII and biosynthetically substituted Sr-PSII employing Time-Resolved Membrane Inlet Mass Spectrometry (TR-MIMS) and a Time-Resolved 17O-Electron-electron Double resonance detected NMR (TR-17O-EDNMR) approach. TR-MIMS resolves the kinetics for incorporation of the oxygen-isotope label into the substrate sites after addition of H218O to the medium, while the magnetic resonance technique allows, in principle, the characterization of all exchangeable oxygen ligands of the Mn4CaO5 cofactor after mixing with H217O. This unique combination shows i) that the central oxygen bridge (O5) of Ca-PSII core complexes isolated from Thermosynechococcus vestitus has, within experimental conditions, the same rate of exchange as the slowly exchanging substrate water (WS) in the TR-MIMS experiments and ii) that the exchange rates of O5 and WS are both enhanced by Ca2+→Sr2+ substitution in a similar manner. In the context of previous TR-MIMS results, this shows that only O5 fulfills all criteria for being WS. This strongly restricts options for the mechanism of water oxidation.
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Affiliation(s)
- Casper de Lichtenberg
- Department of Chemistry- Ångström Laboratorium, Uppsala University, UppsalaS-75120, Sweden
- Department of Chemistry, Chemical Biological Centre, Umeå University, UmeåS-90187, Sweden
| | - Leonid Rapatskiy
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
| | - Michael Reus
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
| | - Eiri Heyno
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
| | - Alexander Schnegg
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
| | - Marc M. Nowaczyk
- Department of Plant Biochemistry, Ruhr-Universität Bochum, BochumD-44780, Germany
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
| | - Johannes Messinger
- Department of Chemistry- Ångström Laboratorium, Uppsala University, UppsalaS-75120, Sweden
- Department of Chemistry, Chemical Biological Centre, Umeå University, UmeåS-90187, Sweden
| | - Nicholas Cox
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
- Research School of Chemistry, Australian National University, Acton ACT2601, Australia
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7
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Drosou M, Pantazis DA. Comprehensive Evaluation of Models for Ammonia Binding to the Oxygen Evolving Complex of Photosystem II. J Phys Chem B 2024; 128:1333-1349. [PMID: 38299511 PMCID: PMC10875651 DOI: 10.1021/acs.jpcb.3c06304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 01/08/2024] [Accepted: 01/17/2024] [Indexed: 02/02/2024]
Abstract
The identity and insertion pathway of the substrate oxygen atoms that are coupled to dioxygen by the oxygen-evolving complex (OEC) remains a central question toward understanding Nature's water oxidation mechanism. In several studies, ammonia has been used as a small "water analogue" to elucidate the pathway of substrate access to the OEC and to aid in determining which of the oxygen ligands of the tetramanganese cluster are substrates for O-O bond formation. On the basis of structural and spectroscopic investigations, five first-sphere binding modes of ammonia have been suggested, involving either substitution of an existing H2O/OH-/O2- group or addition as an extra ligand to a metal ion of the Mn4CaO5 cluster. Some of these modes, specifically the ones involving substitution, have already been subject to spectroscopy-oriented quantum chemical investigations, whereas more recent suggestions that postulate the addition of ammonia have not been examined so far with quantum chemistry for their agreement with spectroscopic data. Herein, we use a common structural framework and theoretical methodology to evaluate structural models of the OEC that represent all proposed modes of first-sphere ammonia interaction with the OEC in its S2 state. Criteria include energetic, magnetic, kinetic, and spectroscopic properties compared against available experimental EPR, ENDOR, ESEEM, and EDNMR data. Our results show that models featuring ammonia replacing one of the two terminal water ligands on Mn4 align best with experimental data, while they definitively exclude substitution of a bridging μ-oxo ligand as well as incorporation of ammonia as a sixth ligand on Mn1 or Mn4.
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Affiliation(s)
- Maria Drosou
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
- Inorganic
Chemistry Laboratory, National and Kapodistrian
University of Athens, Panepistimiopolis, Zografou 15771, Greece
| | - Dimitrios A. Pantazis
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
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8
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Hussein R, Ibrahim M, Bhowmick A, Simon PS, Bogacz I, Doyle MD, Dobbek H, Zouni A, Messinger J, Yachandra VK, Kern JF, Yano J. Evolutionary diversity of proton and water channels on the oxidizing side of photosystem II and their relevance to function. PHOTOSYNTHESIS RESEARCH 2023; 158:91-107. [PMID: 37266800 PMCID: PMC10684718 DOI: 10.1007/s11120-023-01018-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/29/2023] [Indexed: 06/03/2023]
Abstract
One of the reasons for the high efficiency and selectivity of biological catalysts arise from their ability to control the pathways of substrates and products using protein channels, and by modulating the transport in the channels using the interaction with the protein residues and the water/hydrogen-bonding network. This process is clearly demonstrated in Photosystem II (PS II), where its light-driven water oxidation reaction catalyzed by the Mn4CaO5 cluster occurs deep inside the protein complex and thus requires the transport of two water molecules to and four protons from the metal center to the bulk water. Based on the recent advances in structural studies of PS II from X-ray crystallography and cryo-electron microscopy, in this review we compare the channels that have been proposed to facilitate this mass transport in cyanobacteria, red and green algae, diatoms, and higher plants. The three major channels (O1, O4, and Cl1 channels) are present in all species investigated; however, some differences exist in the reported structures that arise from the different composition and arrangement of membrane extrinsic subunits between the species. Among the three channels, the Cl1 channel, including the proton gate, is the most conserved among all photosynthetic species. We also found at least one branch for the O1 channel in all organisms, extending all the way from Ca/O1 via the 'water wheel' to the lumen. However, the extending path after the water wheel varies between most species. The O4 channel is, like the Cl1 channel, highly conserved among all species while having different orientations at the end of the path near the bulk. The comparison suggests that the previously proposed functionality of the channels in T. vestitus (Ibrahim et al., Proc Natl Acad Sci USA 117:12624-12635, 2020; Hussein et al., Nat Commun 12:6531, 2021) is conserved through the species, i.e. the O1-like channel is used for substrate water intake, and the tighter Cl1 and O4 channels for proton release. The comparison does not eliminate the potential role of O4 channel as a water intake channel. However, the highly ordered hydrogen-bonded water wire connected to the Mn4CaO5 cluster via the O4 may strongly suggest that it functions in proton release, especially during the S0 → S1 transition (Saito et al., Nat Commun 6:8488, 2015; Kern et al., Nature 563:421-425, 2018; Ibrahim et al., Proc Natl Acad Sci USA 117:12624-12635, 2020; Sakashita et al., Phys Chem Chem Phys 22:15831-15841, 2020; Hussein et al., Nat Commun 12:6531, 2021).
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Affiliation(s)
- Rana Hussein
- Department of Biology, Humboldt-Universität Zu Berlin, 10099, Berlin, Germany.
| | - Mohamed Ibrahim
- Department of Biology, Humboldt-Universität Zu Berlin, 10099, Berlin, Germany
| | - Asmit Bhowmick
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Philipp S Simon
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Isabel Bogacz
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Margaret D Doyle
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Holger Dobbek
- Department of Biology, Humboldt-Universität Zu Berlin, 10099, Berlin, Germany
| | - Athina Zouni
- Department of Biology, Humboldt-Universität Zu Berlin, 10099, Berlin, Germany
| | - Johannes Messinger
- Molecular Biomimetics, Department of Chemistry-Ångström, Uppsala University, SE 75120, Uppsala, Sweden
- Department of Chemistry, Umeå University, SE 90187, Umeå, Sweden
| | - Vittal K Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jan F Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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9
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Shevela D, Kern JF, Govindjee G, Messinger J. Solar energy conversion by photosystem II: principles and structures. PHOTOSYNTHESIS RESEARCH 2023; 156:279-307. [PMID: 36826741 PMCID: PMC10203033 DOI: 10.1007/s11120-022-00991-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 12/01/2022] [Indexed: 05/23/2023]
Abstract
Photosynthetic water oxidation by Photosystem II (PSII) is a fascinating process because it sustains life on Earth and serves as a blue print for scalable synthetic catalysts required for renewable energy applications. The biophysical, computational, and structural description of this process, which started more than 50 years ago, has made tremendous progress over the past two decades, with its high-resolution crystal structures being available not only of the dark-stable state of PSII, but of all the semi-stable reaction intermediates and even some transient states. Here, we summarize the current knowledge on PSII with emphasis on the basic principles that govern the conversion of light energy to chemical energy in PSII, as well as on the illustration of the molecular structures that enable these reactions. The important remaining questions regarding the mechanism of biological water oxidation are highlighted, and one possible pathway for this fundamental reaction is described at a molecular level.
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Affiliation(s)
- Dmitry Shevela
- Department of Chemistry, Chemical Biological Centre, Umeå University, 90187, Umeå, Sweden.
| | - Jan F Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Govindjee Govindjee
- Department of Plant Biology, Department of Biochemistry and Center of Biophysics & Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Johannes Messinger
- Department of Chemistry, Chemical Biological Centre, Umeå University, 90187, Umeå, Sweden.
- Molecular Biomimetics, Department of Chemistry - Ångström, Uppsala University, 75120, Uppsala, Sweden.
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10
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Greife P, Schönborn M, Capone M, Assunção R, Narzi D, Guidoni L, Dau H. The electron-proton bottleneck of photosynthetic oxygen evolution. Nature 2023; 617:623-628. [PMID: 37138082 DOI: 10.1038/s41586-023-06008-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/23/2023] [Indexed: 05/05/2023]
Abstract
Photosynthesis fuels life on Earth by storing solar energy in chemical form. Today's oxygen-rich atmosphere has resulted from the splitting of water at the protein-bound manganese cluster of photosystem II during photosynthesis. Formation of molecular oxygen starts from a state with four accumulated electron holes, the S4 state-which was postulated half a century ago1 and remains largely uncharacterized. Here we resolve this key stage of photosynthetic O2 formation and its crucial mechanistic role. We tracked 230,000 excitation cycles of dark-adapted photosystems with microsecond infrared spectroscopy. Combining these results with computational chemistry reveals that a crucial proton vacancy is initally created through gated sidechain deprotonation. Subsequently, a reactive oxygen radical is formed in a single-electron, multi-proton transfer event. This is the slowest step in photosynthetic O2 formation, with a moderate energetic barrier and marked entropic slowdown. We identify the S4 state as the oxygen-radical state; its formation is followed by fast O-O bonding and O2 release. In conjunction with previous breakthroughs in experimental and computational investigations, a compelling atomistic picture of photosynthetic O2 formation emerges. Our results provide insights into a biological process that is likely to have occurred unchanged for the past three billion years, which we expect to support the knowledge-based design of artificial water-splitting systems.
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Affiliation(s)
- Paul Greife
- Department of Physics, Freie Universität, Berlin, Germany
| | | | - Matteo Capone
- Department of Information Engineering, Computer Science and Mathematics, University of L'Aquila, L'Aquila, Italy
- Department of Physical and Chemical Sciences, University of L'Aquila, L'Aquila, Italy
| | | | - Daniele Narzi
- Department of Physical and Chemical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Leonardo Guidoni
- Department of Physical and Chemical Sciences, University of L'Aquila, L'Aquila, Italy.
| | - Holger Dau
- Department of Physics, Freie Universität, Berlin, Germany.
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11
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Amin M. Predicting the oxidation states of Mn ions in the oxygen-evolving complex of photosystem II using supervised and unsupervised machine learning. PHOTOSYNTHESIS RESEARCH 2023; 156:89-100. [PMID: 35896927 PMCID: PMC10070209 DOI: 10.1007/s11120-022-00941-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/13/2022] [Indexed: 05/21/2023]
Abstract
Serial Femtosecond Crystallography at the X-ray Free Electron Laser (XFEL) sources enabled the imaging of the catalytic intermediates of the oxygen evolution reaction of Photosystem II (PSII). However, due to the incoherent transition of the S-states, the resolved structures are a convolution from different catalytic states. Here, we train Decision Tree Classifier and K-means clustering models on Mn compounds obtained from the Cambridge Crystallographic Database to predict the S-state of the X-ray, XFEL, and CryoEM structures by predicting the Mn's oxidation states in the oxygen-evolving complex. The model agrees mostly with the XFEL structures in the dark S1 state. However, significant discrepancies are observed for the excited XFEL states (S2, S3, and S0) and the dark states of the X-ray and CryoEM structures. Furthermore, there is a mismatch between the predicted S-states within the two monomers of the same dimer, mainly in the excited states. We validated our model against other metalloenzymes, the valence bond model and the Mn spin densities calculated using density functional theory for two of the mismatched predictions of PSII. The model suggests designing a more optimized sample delivery and illumiation systems are crucial to precisely resolve the geometry of the advanced S-states to overcome the noncoherent S-state transition. In addition, significant radiation damage is observed in X-ray and CryoEM structures, particularly at the dangler Mn center (Mn4). Our model represents a valuable tool for investigating the electronic structure of the catalytic metal cluster of PSII to understand the water splitting mechanism.
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Affiliation(s)
- Muhamed Amin
- Department of Sciences, University College Groningen, University of Groningen, Hoendiepskade 23/24, 9718 BG, Groningen, The Netherlands.
- Rijksuniversiteit Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, Netherlands.
- Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607, Hamburg, Germany.
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12
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Guo Y, Messinger J, Kloo L, Sun L. Alternative Mechanism for O 2 Formation in Natural Photosynthesis via Nucleophilic Oxo-Oxo Coupling. J Am Chem Soc 2023; 145:4129-4141. [PMID: 36763485 DOI: 10.1021/jacs.2c12174] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
O2 formation in photosystem II (PSII) is a vital event on Earth, but the exact mechanism remains unclear. The presently prevailing theoretical model is "radical coupling" (RC) involving a Mn(IV)-oxyl unit in an "open-cubane" Mn4CaO6 cluster, which is supported experimentally by the S3 state of cyanobacterial PSII featuring an additional Mn-bound oxygenic ligand. However, it was recently proposed that the major structural form of the S3 state of higher plants lacks this extra ligand, and that the resulting S4 state would feature instead a penta-coordinate dangler Mn(V)=oxo, covalently linked to a "closed-cubane" Mn3CaO4 cluster. For this proposal, we explore here a large number of possible pathways of O-O bond formation and demonstrate that the "nucleophilic oxo-oxo coupling" (NOOC) between Mn(V)=oxo and μ3-oxo is the only eligible mechanism in such a system. The reaction is facilitated by a specific conformation of the cluster and concomitant water binding, which is delayed compared to the RC mechanism. An energetically feasible process is described starting from the valid S4 state through the sequential formation of peroxide and superoxide, followed by O2 release and a second water insertion. The newly found mechanism is consistent with available experimental thermodynamic and kinetic data and thus a viable alternative pathway for O2 formation in natural photosynthesis, in particular for higher plants.
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Affiliation(s)
- Yu Guo
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou 310024, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
| | - Johannes Messinger
- Department of Chemistry, Umeå University, Linnaeus väg 6 (KBC huset), Umeå SE-90187, Sweden
- Molecular Biomimetics, Department of Chemistry─Ångström Laboratory, Uppsala University, Uppsala SE-75120, Sweden
| | - Lars Kloo
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm SE-10044, Sweden
| | - Licheng Sun
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou 310024, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
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13
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Tamura H, Saito K, Nishio S, Ishikita H. Electron-Transfer Route in the Early Oxidation States of the Mn 4CaO 5 Cluster in Photosystem II. J Phys Chem B 2023; 127:205-211. [PMID: 36542840 PMCID: PMC9841979 DOI: 10.1021/acs.jpcb.2c08246] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/07/2022] [Indexed: 12/24/2022]
Abstract
The electron transfer from the oxygen-evolving Mn4CaO5 cluster to the electron acceptor D1-Tyr161 (TyrZ) is a prerequisite for water oxidation and O2 evolution. Here, we analyzed the electronic coupling in the rate-limiting electron-transfer transitions using a combined quantum mechanical/molecular mechanical/polarizable continuum model approach. In the S0 to S1 transition, the electronic coupling between the electron-donor Mn3(III) and TyrZ is small (2 meV). In contrast, the electronic coupling between the dangling Mn4(III) and TyrZ is significantly large (172 meV), which suggests that the electron transfer proceeds from Mn3(III) to TyrZ via Mn4(III). In the S1 to S2 transition, the electronic coupling between Mn4(III) and TyrZ is also larger (124 meV) than that between Mn1(III) and TyrZ (1 meV), which favors the formation of the open-cubane S2 conformation with Mn4(IV) over the formation of the closed-cubane S2 conformation with Mn1(IV). In the S0 to S1 and S1 to S2 transitions, the Mn4 d-orbital and the TyrZ π-orbital are hybridized via D1-Asp170, which suggests that D1-Asp170 commonly provides a dominant electron-transfer route.
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Affiliation(s)
- Hiroyuki Tamura
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo153-8904, Japan
| | - Keisuke Saito
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo153-8904, Japan
| | - Shunya Nishio
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo113-8654, Japan
| | - Hiroshi Ishikita
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo153-8904, Japan
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14
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Simon PS, Makita H, Bogacz I, Fuller F, Bhowmick A, Hussein R, Ibrahim M, Zhang M, Chatterjee R, Cheah MH, Chernev P, Doyle MD, Brewster AS, Alonso-Mori R, Sauter NK, Bergmann U, Dobbek H, Zouni A, Messinger J, Kern J, Yachandra VK, Yano J. Capturing the sequence of events during the water oxidation reaction in photosynthesis using XFELs. FEBS Lett 2023; 597:30-37. [PMID: 36310373 PMCID: PMC9839502 DOI: 10.1002/1873-3468.14527] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Revised: 10/13/2022] [Accepted: 10/17/2022] [Indexed: 01/17/2023]
Abstract
Ever since the discovery that Mn was required for oxygen evolution in plants by Pirson in 1937 and the period-four oscillation in flash-induced oxygen evolution by Joliot and Kok in the 1970s, understanding of this process has advanced enormously using state-of-the-art methods. The most recent in this series of innovative techniques was the introduction of X-ray free-electron lasers (XFELs) a decade ago, which led to another quantum leap in the understanding in this field, by enabling operando X-ray structural and X-ray spectroscopy studies at room temperature. This review summarizes the current understanding of the structure of Photosystem II (PS II) and its catalytic centre, the Mn4 CaO5 complex, in the intermediate Si (i = 0-4)-states of the Kok cycle, obtained using XFELs.
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Affiliation(s)
- Philipp S Simon
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Hiroki Makita
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Isabel Bogacz
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Franklin Fuller
- Pulse Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Asmit Bhowmick
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Rana Hussein
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Mohamed Ibrahim
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Miao Zhang
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Ruchira Chatterjee
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Mun Hon Cheah
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Petko Chernev
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Margaret D Doyle
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Aaron S Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Roberto Alonso-Mori
- LINAC Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Nicholas K Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Uwe Bergmann
- Department of Physics, University of Wisconsin-Madison, Madison, WI, USA
| | - Holger Dobbek
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Athina Zouni
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Johannes Messinger
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala, Sweden
- Department of Chemistry, Umeå University, Umeå, Sweden
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Vittal K Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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15
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Lubitz W, Pantazis DA, Cox N. Water oxidation in oxygenic photosynthesis studied by magnetic resonance techniques. FEBS Lett 2023; 597:6-29. [PMID: 36409002 DOI: 10.1002/1873-3468.14543] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 11/23/2022]
Abstract
The understanding of light-induced biological water oxidation in oxygenic photosynthesis is of great importance both for biology and (bio)technological applications. The chemically difficult multistep reaction takes place at a unique protein-bound tetra-manganese/calcium cluster in photosystem II whose structure has been elucidated by X-ray crystallography (Umena et al. Nature 2011, 473, 55). The cluster moves through several intermediate states in the catalytic cycle. A detailed understanding of these intermediates requires information about the spatial and electronic structure of the Mn4 Ca complex; the latter is only available from spectroscopic techniques. Here, the important role of Electron Paramagnetic Resonance (EPR) and related double resonance techniques (ENDOR, EDNMR), complemented by quantum chemical calculations, is described. This has led to the elucidation of the cluster's redox and protonation states, the valence and spin states of the manganese ions and the interactions between them, and contributed substantially to the understanding of the role of the protein surrounding, as well as the binding and processing of the substrate water molecules, the O-O bond formation and dioxygen release. Based on these data, models for the water oxidation cycle are developed.
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Affiliation(s)
- Wolfgang Lubitz
- Max-Planck-Institut für Chemische Energiekonversion, Mülheim/Ruhr, Germany
| | | | - Nicholas Cox
- Research School of Chemistry, Australian National University, Canberra, ACT, Australia
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16
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Isobe H, Shoji M, Suzuki T, Shen JR, Yamaguchi K. Roles of the Flexible Primary Coordination Sphere of the Mn 4CaO x Cluster: What Are the Immediate Decay Products of the S3 State? J Phys Chem B 2022; 126:7212-7228. [DOI: 10.1021/acs.jpcb.2c02596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hiroshi Isobe
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Mitsuo Shoji
- Center for Computational Science, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Takayoshi Suzuki
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Kizashi Yamaguchi
- Institute for NanoScience Design, Osaka University, Toyonaka, Osaka 560-0043, Japan
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17
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Guo Y, Messinger J, Kloo L, Sun L. Reversible Structural Isomerization of Nature's Water Oxidation Catalyst Prior to O-O Bond Formation. J Am Chem Soc 2022; 144:11736-11747. [PMID: 35748306 PMCID: PMC9264352 DOI: 10.1021/jacs.2c03528] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
![]()
Photosynthetic water
oxidation is catalyzed by a manganese–calcium
oxide cluster, which experiences five “S-states” during
a light-driven reaction cycle. The unique “distorted chair”-like
geometry of the Mn4CaO5(6) cluster shows structural
flexibility that has been frequently proposed to involve “open”
and “closed”-cubane forms from the S1 to
S3 states. The isomers are interconvertible in the S1 and S2 states, while in the S3 state,
the open-cubane structure is observed to dominate inThermosynechococcus elongatus (cyanobacteria) samples.
In this work, using density functional theory calculations, we go
beyond the S3+Yz state to the S3nYz• → S4+Yz step, and report for the first time
that the reversible isomerism, which is suppressed in the S3+Yz state, is fully recovered
in the ensuing S3nYz• state due to the proton release
from a manganese-bound water ligand. The altered coordination strength
of the manganese–ligand facilitates formation of the closed-cubane
form, in a dynamic equilibrium with the open-cubane form. This tautomerism
immediately preceding dioxygen formation may constitute the rate limiting
step for O2 formation, and exert a significant influence
on the water oxidation mechanism in photosystem II.
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Affiliation(s)
- Yu Guo
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou 310024, China.,Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
| | - Johannes Messinger
- Department of Chemistry, Umeå University, Linnaeus väg 6 (KBC huset), SE-90187 Umeå, Sweden.,Molecular Biomimetics, Department of Chemistry─Ångström Laboratory, Uppsala University, SE-75120 Uppsala, Sweden
| | - Lars Kloo
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden
| | - Licheng Sun
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou 310024, China.,Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
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18
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Gates C, Ananyev G, Roy-Chowdhury S, Cullinane B, Miller M, Fromme P, Dismukes GC. Why Did Nature Choose Manganese over Cobalt to Make Oxygen Photosynthetically on the Earth? J Phys Chem B 2022; 126:3257-3268. [PMID: 35446582 DOI: 10.1021/acs.jpcb.2c00749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
All contemporary oxygenic phototrophs─from primitive cyanobacteria to complex multicellular plants─split water using a single invariant cluster comprising Mn4CaO5 (the water oxidation catalyst) as the catalyst within photosystem II, the universal oxygenic reaction center of natural photosynthesis. This cluster is unstable outside of PSII and can be reconstituted, both in vivo and in vitro, using elemental aqueous ions and light, via photoassembly. Here, we demonstrate the first functional substitution of manganese in any oxygenic reaction center by in vitro photoassembly. Following complete removal of inorganic cofactors from cyanobacterial photosystem II microcrystal (PSIIX), photoassembly with free cobalt (Co2+), calcium (Ca2+), and water (OH-) restores O2 evolution activity. Photoassembly occurs at least threefold faster using Co2+ versus Mn2+ due to a higher quantum yield for PSIIX-mediated charge separation (P*): Co2+ → P* → Co3+QA-. However, this kinetic preference for Co2+ over native Mn2+ during photoassembly is offset by significantly poorer catalytic activity (∼25% of the activity with Mn2+) and ∼3- to 30-fold faster photoinactivation rate. The resulting reconstituted Co-PSIIX oxidizes water by the standard four-flash photocycle, although they produce 4-fold less O2 per PSII, suggested to arise from faster charge recombination (Co3+QA ← Co4+QA-) in the catalytic cycle. The faster photoinactivation of reconstituted Co-PSIIX occurs under anaerobic conditions during the catalytic cycle, suggesting direct photodamage without the involvement of O2. Manganese offers two advantages for oxygenic phototrophs, which may explain its exclusive retention throughout Darwinian evolution: significantly slower charge recombination (Mn3+QA ← Mn4+QA-) permits more water oxidation at low and fluctuating solar irradiation (greater net energy conversion) and much greater tolerance to photodamage at high light intensities (Mn4+ is less oxidizing than Co4+). Future work to identify the chemical nature of the intermediates will be needed for further interpretation.
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Affiliation(s)
- Colin Gates
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey 08854, United States.,Department of Chemistry & Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States.,Department of Computational Biology & Molecular Biophysics, Rutgers University, Piscataway, New Jersey 08854, United States.,Department of Chemistry & Biochemistry, Loyola University Chicago, Chicago, Illinois 60660, United States
| | - Gennady Ananyev
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey 08854, United States.,Department of Chemistry & Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Shatabdi Roy-Chowdhury
- Biodesign Center for Applied Structural Discovery and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85281, United States
| | - Brendan Cullinane
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey 08854, United States.,Department of Molecular Biology & Biochemistry, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Mathias Miller
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey 08854, United States.,Department of Molecular Biology & Biochemistry, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Petra Fromme
- Biodesign Center for Applied Structural Discovery and School of Molecular Sciences, Arizona State University, Tempe, Arizona 85281, United States
| | - G Charles Dismukes
- Waksman Institute of Microbiology, Rutgers University, Piscataway, New Jersey 08854, United States.,Department of Chemistry & Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States
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19
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Allgöwer F, Gamiz-Hernandez AP, Rutherford AW, Kaila VRI. Molecular Principles of Redox-Coupled Protonation Dynamics in Photosystem II. J Am Chem Soc 2022; 144:7171-7180. [PMID: 35421304 PMCID: PMC9052759 DOI: 10.1021/jacs.1c13041] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Photosystem II (PSII) catalyzes light-driven water oxidization, releasing O2 into the atmosphere and transferring the electrons for the synthesis of biomass. However, despite decades of structural and functional studies, the water oxidation mechanism of PSII has remained puzzling and a major challenge for modern chemical research. Here, we show that PSII catalyzes redox-triggered proton transfer between its oxygen-evolving Mn4O5Ca cluster and a nearby cluster of conserved buried ion-pairs, which are connected to the bulk solvent via a proton pathway. By using multi-scale quantum and classical simulations, we find that oxidation of a redox-active Tyrz (Tyr161) lowers the reaction barrier for the water-mediated proton transfer from a Ca2+-bound water molecule (W3) to Asp61 via conformational changes in a nearby ion-pair (Asp61/Lys317). Deprotonation of this W3 substrate water triggers its migration toward Mn1 to a position identified in recent X-ray free-electron laser (XFEL) experiments [Ibrahim et al. Proc. Natl. Acad. Sci. USA 2020, 117, 12,624-12,635]. Further oxidation of the Mn4O5Ca cluster lowers the proton transfer barrier through the water ligand sphere of the Mn4O5Ca cluster to Asp61 via a similar ion-pair dissociation process, while the resulting Mn-bound oxo/oxyl species leads to O2 formation by a radical coupling mechanism. The proposed redox-coupled protonation mechanism shows a striking resemblance to functional motifs in other enzymes involved in biological energy conversion, with an interplay between hydration changes, ion-pair dynamics, and electric fields that modulate the catalytic barriers.
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Affiliation(s)
- Friederike Allgöwer
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Ana P Gamiz-Hernandez
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - A William Rutherford
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Ville R I Kaila
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
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20
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Bigness A, Vaddypally S, Zdilla MJ, Mendoza-Cortes JL. Ubiquity of cubanes in bioinorganic relevant compounds. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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21
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Debus RJ. Alteration of the O 2-Producing Mn 4Ca Cluster in Photosystem II by the Mutation of a Metal Ligand. Biochemistry 2021; 60:3841-3855. [PMID: 34898175 DOI: 10.1021/acs.biochem.1c00504] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The O2-evolving Mn4Ca cluster in photosystem II (PSII) is arranged as a distorted Mn3Ca cube that is linked to a fourth Mn ion (denoted as Mn4) by two oxo bridges. The Mn4 and Ca ions are bridged by residue D1-D170. This is also the only residue known to participate in the high-affinity Mn(II) site that participates in the light-driven assembly of the Mn4Ca cluster. In this study, we use Fourier transform infrared difference spectroscopy to characterize the impact of the D1-D170E mutation. On the basis of analyses of carboxylate and carbonyl stretching modes and the O-H stretching modes of hydrogen-bonded water molecules, we show that this mutation alters the extensive network of hydrogen bonds that surrounds the Mn4Ca cluster in the same manner as that of many other mutations. It also alters the equilibrium between conformers of the Mn4Ca cluster in the dark-stable S1 state so that a high-spin form of the S2 state is produced during the S1-to-S2 transition instead of the low-spin form that gives rise to the S2 state multiline electron paramagnetic resonance signal. The mutation may also change the coordination mode of the carboxylate group at position 170 to unidentate ligation of Mn4. This is the first mutation of a metal ligand in PSII that substantially impacts the spectroscopic signatures of the Mn4Ca cluster without substantially eliminating O2 evolution. The results have significant implications for our understanding of the roles of alternate active/inactive conformers of the Mn4Ca cluster in the mechanism of O2 formation.
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Affiliation(s)
- Richard J Debus
- Department of Biochemistry, University of California, Riverside, California 92521, United States
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22
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Hussein R, Ibrahim M, Bhowmick A, Simon PS, Chatterjee R, Lassalle L, Doyle M, Bogacz I, Kim IS, Cheah MH, Gul S, de Lichtenberg C, Chernev P, Pham CC, Young ID, Carbajo S, Fuller FD, Alonso-Mori R, Batyuk A, Sutherlin KD, Brewster AS, Bolotovsky R, Mendez D, Holton JM, Moriarty NW, Adams PD, Bergmann U, Sauter NK, Dobbek H, Messinger J, Zouni A, Kern J, Yachandra VK, Yano J. Structural dynamics in the water and proton channels of photosystem II during the S 2 to S 3 transition. Nat Commun 2021; 12:6531. [PMID: 34764256 PMCID: PMC8585918 DOI: 10.1038/s41467-021-26781-z] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 10/21/2021] [Indexed: 11/30/2022] Open
Abstract
Light-driven oxidation of water to molecular oxygen is catalyzed by the oxygen-evolving complex (OEC) in Photosystem II (PS II). This multi-electron, multi-proton catalysis requires the transport of two water molecules to and four protons from the OEC. A high-resolution 1.89 Å structure obtained by averaging all the S states and refining the data of various time points during the S2 to S3 transition has provided better visualization of the potential pathways for substrate water insertion and proton release. Our results indicate that the O1 channel is the likely water intake pathway, and the Cl1 channel is the likely proton release pathway based on the structural rearrangements of water molecules and amino acid side chains along these channels. In particular in the Cl1 channel, we suggest that residue D1-E65 serves as a gate for proton transport by minimizing the back reaction. The results show that the water oxidation reaction at the OEC is well coordinated with the amino acid side chains and the H-bonding network over the entire length of the channels, which is essential in shuttling substrate waters and protons.
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Affiliation(s)
- Rana Hussein
- grid.7468.d0000 0001 2248 7639Institut für Biologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Mohamed Ibrahim
- grid.7468.d0000 0001 2248 7639Institut für Biologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Asmit Bhowmick
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Philipp S. Simon
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Ruchira Chatterjee
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Louise Lassalle
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Margaret Doyle
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Isabel Bogacz
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - In-Sik Kim
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Mun Hon Cheah
- grid.8993.b0000 0004 1936 9457Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University, SE 75120 Uppsala, Sweden
| | - Sheraz Gul
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Casper de Lichtenberg
- grid.8993.b0000 0004 1936 9457Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University, SE 75120 Uppsala, Sweden ,grid.12650.300000 0001 1034 3451Department of Chemistry, Umeå University, SE 90187 Umeå, Sweden
| | - Petko Chernev
- grid.8993.b0000 0004 1936 9457Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University, SE 75120 Uppsala, Sweden
| | - Cindy C. Pham
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Iris D. Young
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Sergio Carbajo
- grid.512023.70000 0004 6047 9447Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Franklin D. Fuller
- grid.512023.70000 0004 6047 9447Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Roberto Alonso-Mori
- grid.512023.70000 0004 6047 9447Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Alex Batyuk
- grid.512023.70000 0004 6047 9447Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Kyle D. Sutherlin
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Aaron S. Brewster
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Robert Bolotovsky
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Derek Mendez
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - James M. Holton
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Nigel W. Moriarty
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Paul D. Adams
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Department of Bioengineering, University of California, Berkeley, CA 94720 USA
| | - Uwe Bergmann
- grid.14003.360000 0001 2167 3675Department of Physics, University of Wisconsin–Madison, Madison, WI 53706 USA
| | - Nicholas K. Sauter
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Holger Dobbek
- grid.7468.d0000 0001 2248 7639Institut für Biologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany
| | - Johannes Messinger
- Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University, SE 75120, Uppsala, Sweden. .,Department of Chemistry, Umeå University, SE 90187, Umeå, Sweden.
| | - Athina Zouni
- Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany.
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
| | - Vittal K. Yachandra
- grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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23
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Fransson T, Alonso-Mori R, Chatterjee R, Cheah MH, Ibrahim M, Hussein R, Zhang M, Fuller F, Gul S, Kim IS, Simon PS, Bogacz I, Makita H, de Lichtenberg C, Song S, Batyuk A, Sokaras D, Massad R, Doyle M, Britz A, Weninger C, Zouni A, Messinger J, Yachandra VK, Yano J, Kern J, Bergmann U. Effects of x-ray free-electron laser pulse intensity on the Mn K β 1,3 x-ray emission spectrum in photosystem II-A case study for metalloprotein crystals and solutions. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:064302. [PMID: 34849380 PMCID: PMC8610604 DOI: 10.1063/4.0000130] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/24/2021] [Indexed: 05/21/2023]
Abstract
In the last ten years, x-ray free-electron lasers (XFELs) have been successfully employed to characterize metalloproteins at room temperature using various techniques including x-ray diffraction, scattering, and spectroscopy. The approach has been to outrun the radiation damage by using femtosecond (fs) x-ray pulses. An example of an important and damage sensitive active metal center is the Mn4CaO5 cluster in photosystem II (PS II), the catalytic site of photosynthetic water oxidation. The combination of serial femtosecond x-ray crystallography and Kβ x-ray emission spectroscopy (XES) has proven to be a powerful multimodal approach for simultaneously probing the overall protein structure and the electronic state of the Mn4CaO5 cluster throughout the catalytic (Kok) cycle. As the observed spectral changes in the Mn4CaO5 cluster are very subtle, it is critical to consider the potential effects of the intense XFEL pulses on the Kβ XES signal. We report here a systematic study of the effects of XFEL peak power, beam focus, and dose on the Mn Kβ1,3 XES spectra in PS II over a wide range of pulse parameters collected over seven different experimental runs using both microcrystal and solution PS II samples. Our findings show that for beam intensities ranging from ∼5 × 1015 to 5 × 1017 W/cm2 at a pulse length of ∼35 fs, the spectral effects are small compared to those observed between S-states in the Kok cycle. Our results provide a benchmark for other XFEL-based XES studies on metalloproteins, confirming the viability of this approach.
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Affiliation(s)
- Thomas Fransson
- Department of Theoretical Chemistry and Biology, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Roberto Alonso-Mori
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Ruchira Chatterjee
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Mun Hon Cheah
- Department of Chemistry – Ångström Laboratory, Molecular Biomimetics, Uppsala University, SE 75120 Uppsala, Sweden
| | - Mohamed Ibrahim
- Humboldt-Universität zu Berlin, Department of Biology, 10099 Berlin, Germany
| | - Rana Hussein
- Humboldt-Universität zu Berlin, Department of Biology, 10099 Berlin, Germany
| | - Miao Zhang
- Humboldt-Universität zu Berlin, Department of Biology, 10099 Berlin, Germany
| | - Franklin Fuller
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Sheraz Gul
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - In-Sik Kim
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Philipp S. Simon
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Isabel Bogacz
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Hiroki Makita
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | | | - Sanghoon Song
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Alexander Batyuk
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Ramzi Massad
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Margaret Doyle
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | | | | | - Athina Zouni
- Humboldt-Universität zu Berlin, Department of Biology, 10099 Berlin, Germany
| | | | - Vittal K. Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Uwe Bergmann
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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24
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Wang M, Zhang Y, Chen C, Zhang C, Jiang J, Weng Y. Structural Reorganization of a Synthetic Mimic of the Oxygen-Evolving Center in Multiple Redox Transitions Revealed by Electrochemical FTIR Spectra. J Phys Chem Lett 2021; 12:9830-9839. [PMID: 34605651 DOI: 10.1021/acs.jpclett.1c02689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In photosynthesis, the protein-bound natural oxygen-evolving center (OEC) undergoes multiple oxidation-state transitions in the light-driven water splitting reactions with a stepwise change in the oxidation potential. Because the protein is vulnerable to electrochemical oxidation, the multiple oxidation/reduction-state transitions can hardly be achieved by electrochemical oxidation with a continuous change in the oxidation potential. An OEC mimic that can undergo four redox transitions has been synthesized (Zhang, C., Science, 2015, 348, 690-693). Here we report an electrochemical FTIR spectroscopic study of this synthetic complex at its multiple oxidation states in the low-frequency region for Mn-O bonds. Compared with those of the native OEC induced by pulsed laser flashes, our results also show the existence of two structural isomers in the S2 state, with the closed cubane conformer being more stable than the open cubane conformer, in contrast to that of the native OEC in which the open form is more stable.
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Affiliation(s)
- Mohan Wang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying Zhang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Changhui Chen
- Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Chunxi Zhang
- Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Junguang Jiang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
| | - Yuxiang Weng
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523000, China
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25
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de Lichtenberg C, Kim CJ, Chernev P, Debus RJ, Messinger J. The exchange of the fast substrate water in the S 2 state of photosystem II is limited by diffusion of bulk water through channels - implications for the water oxidation mechanism. Chem Sci 2021; 12:12763-12775. [PMID: 34703563 PMCID: PMC8494045 DOI: 10.1039/d1sc02265b] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 08/31/2021] [Indexed: 12/02/2022] Open
Abstract
The molecular oxygen we breathe is produced from water-derived oxygen species bound to the Mn4CaO5 cluster in photosystem II (PSII). Present research points to the central oxo-bridge O5 as the 'slow exchanging substrate water (Ws)', while, in the S2 state, the terminal water ligands W2 and W3 are both discussed as the 'fast exchanging substrate water (Wf)'. A critical point for the assignment of Wf is whether or not its exchange with bulk water is limited by barriers in the channels leading to the Mn4CaO5 cluster. In this study, we measured the rates of H2 16O/H2 18O substrate water exchange in the S2 and S3 states of PSII core complexes from wild-type (WT) Synechocystis sp. PCC 6803, and from two mutants, D1-D61A and D1-E189Q, that are expected to alter water access via the Cl1/O4 channels and the O1 channel, respectively. We found that the exchange rates of Wf and Ws were unaffected by the E189Q mutation (O1 channel), but strongly perturbed by the D61A mutation (Cl1/O4 channel). It is concluded that all channels have restrictions limiting the isotopic equilibration of the inner water pool near the Mn4CaO5 cluster, and that D61 participates in one such barrier. In the D61A mutant this barrier is lowered so that Wf exchange occurs more rapidly. This finding removes the main argument against Ca-bound W3 as fast substrate water in the S2 state, namely the indifference of the rate of Wf exchange towards Ca/Sr substitution.
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Affiliation(s)
- Casper de Lichtenberg
- Department of Chemistry, Umeå University Linnaeus väg 6 (KBC huset), SE-901 87 Umeå Sweden
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University POB 523 SE-75120 Uppsala Sweden
| | - Christopher J Kim
- Department of Biochemistry, University of California Riverside California 92521 USA
| | - Petko Chernev
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University POB 523 SE-75120 Uppsala Sweden
| | - Richard J Debus
- Department of Biochemistry, University of California Riverside California 92521 USA
| | - Johannes Messinger
- Department of Chemistry, Umeå University Linnaeus väg 6 (KBC huset), SE-901 87 Umeå Sweden
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University POB 523 SE-75120 Uppsala Sweden
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26
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Drosou M, Pantazis DA. Redox Isomerism in the S 3 State of the Oxygen-Evolving Complex Resolved by Coupled Cluster Theory. Chemistry 2021; 27:12815-12825. [PMID: 34288176 PMCID: PMC8518824 DOI: 10.1002/chem.202101567] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Indexed: 01/19/2023]
Abstract
The electronic and geometric structures of the water-oxidizing complex of photosystem II in the steps of the catalytic cycle that precede dioxygen evolution remain hotly debated. Recent structural and spectroscopic investigations support contradictory redox formulations for the active-site Mn4 CaOx cofactor in the final metastable S3 state. These range from the widely accepted MnIV 4 oxo-hydroxo model, which presumes that O-O bond formation occurs in the ultimate transient intermediate (S4 ) of the catalytic cycle, to a MnIII 2 MnIV 2 peroxo model representative of the contrasting "early-onset" O-O bond formation hypothesis. Density functional theory energetics of suggested S3 redox isomers are inconclusive because of extreme functional dependence. Here, we use the power of the domain-based local pair natural orbital approach to coupled cluster theory, DLPNO-CCSD(T), to present the first correlated wave function theory calculations of relative stabilities for distinct redox-isomeric forms of the S3 state. Our results enabled us to evaluate conflicting models for the S3 state of the oxygen-evolving complex (OEC) and to quantify the accuracy of lower-level theoretical approaches. Our assessment of the relevance of distinct redox-isomeric forms for the mechanism of biological water oxidation strongly disfavors the scenario of early-onset O-O formation advanced by literal interpretations of certain crystallographic models. This work serves as a case study in the application of modern coupled cluster implementations to redox isomerism problems in oligonuclear transition metal systems.
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Affiliation(s)
- Maria Drosou
- Inorganic Chemistry LaboratoryNational and Kapodistrian University of AthensPanepistimiopolisZografou15771Greece
| | - Dimitrios A. Pantazis
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an derRuhrGermany
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27
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Lang SM, Zimmermann N, Bernhardt TM, Barnett RN, Yoon B, Landman U. Size, Stoichiometry, Dimensionality, and Ca Doping of Manganese Oxide-Based Water Oxidation Clusters: An Oxyl/Hydroxy Mechanism for Oxygen-Oxygen Coupling. J Phys Chem Lett 2021; 12:5248-5255. [PMID: 34048261 DOI: 10.1021/acs.jpclett.1c01299] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Gas-phase ion-trap reactivity experiments and density functional simulations reveal that water oxidation to H2O2 mediated by (calcium) manganese oxide clusters proceeds via formation of a terminal oxyl radical followed by oxyl/hydroxy O-O coupling. This mechanism is predicted to be energetically feasible for Mn2Oy+ (y = 2-4) and the binary CaMn3O4+, in agreement with the experimental observations. In contrast, the reaction does not proceed for the tetramanganese oxides Mn4Oy+ (y = 4-6) under these experimental conditions. This is attributed to the high fluxionality of the tetramanganese clusters, resulting in the instability of the terminal oxyl radical as well as an energetically unfavorable change of the spin state required for H2O2 formation. Ca doping, yielding a symmetry-broken lower-symmetry three-dimensional (3D) CaMn3O4+ cluster, results in structural stabilization of the oxyl radical configuration, accompanied by a favorable coupling between potential energy surfaces with different spin states, thus enabling the cluster-mediated water oxidation reaction and H2O2 formation.
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Affiliation(s)
- Sandra M Lang
- Institute of Surface Chemistry and Catalysis, University of Ulm, 89069 Ulm, Germany
| | - Nina Zimmermann
- Institute of Surface Chemistry and Catalysis, University of Ulm, 89069 Ulm, Germany
| | - Thorsten M Bernhardt
- Institute of Surface Chemistry and Catalysis, University of Ulm, 89069 Ulm, Germany
| | - Robert N Barnett
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, United States
| | - Bokwon Yoon
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, United States
| | - Uzi Landman
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, United States
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28
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Drosou M, Zahariou G, Pantazis DA. Orientational Jahn-Teller Isomerism in the Dark-Stable State of Nature's Water Oxidase. Angew Chem Int Ed Engl 2021; 60:13493-13499. [PMID: 33830630 PMCID: PMC8252073 DOI: 10.1002/anie.202103425] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Indexed: 01/31/2023]
Abstract
The tetramanganese–calcium cluster of the oxygen‐evolving complex of photosystem II adopts electronically and magnetically distinct but interconvertible valence isomeric forms in its first light‐driven oxidized catalytic state, S2. This bistability is implicated in gating the final catalytic states preceding O−O bond formation, but it is unknown how the biological system enables its emergence and controls its effect. Here we show that the Mn4CaO5 cluster in the resting (dark‐stable) S1 state adopts orientational Jahn–Teller isomeric forms arising from a directional change in electronic configuration of the “dangler” MnIII ion. The isomers are consistent with available structural data and explain previously unresolved electron paramagnetic resonance spectroscopic observations on the S1 state. This unique isomerism in the resting state is shown to be the electronic origin of valence isomerism in the S2 state, establishing a functional role of orientational Jahn–Teller isomerism unprecedented in biological or artificial catalysis.
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Affiliation(s)
- Maria Drosou
- Inorganic Chemistry Laboratory, National and Kapodistrian University of Athens, Panepistimiopolis, Zografou, 15771, Greece
| | - Georgia Zahariou
- Institute of Nanoscience & Nanotechnology, NCSR "Demokritos", Athens, 15310, Greece
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
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29
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Drosou M, Zahariou G, Pantazis DA. Orientational Jahn–Teller Isomerism in the Dark‐Stable State of Nature's Water Oxidase. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103425] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Maria Drosou
- Inorganic Chemistry Laboratory National and Kapodistrian University of Athens, Panepistimiopolis Zografou 15771 Greece
| | - Georgia Zahariou
- Institute of Nanoscience & Nanotechnology, NCSR “Demokritos” Athens 15310 Greece
| | - Dimitrios A. Pantazis
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
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30
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Kaur D, Zhang Y, Reiss KM, Mandal M, Brudvig GW, Batista VS, Gunner MR. Proton exit pathways surrounding the oxygen evolving complex of photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148446. [PMID: 33964279 DOI: 10.1016/j.bbabio.2021.148446] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 04/29/2021] [Accepted: 05/01/2021] [Indexed: 12/17/2022]
Abstract
Photosystem II allows water to be the primary electron source for the photosynthetic electron transfer chain. Water is oxidized to dioxygen at the Oxygen Evolving Complex (OEC), a Mn4CaO5 inorganic core embedded on the lumenal side of PSII. Water-filled channels surrounding the OEC must bring in substrate water molecules, remove the product protons to the lumen, and may transport the product oxygen. Three water-filled channels, denoted large, narrow, and broad, extend from the OEC towards the aqueous surface more than 15 Å away. However, the role of each pathway in the transport in and out of the OEC is yet to be established. Here, we combine Molecular Dynamics (MD), Multi Conformation Continuum Electrostatics (MCCE) and Network Analysis to compare and contrast the three potential proton transfer paths. Hydrogen bond network analysis shows that near the OEC the waters are highly interconnected with similar free energy for hydronium at all locations. The paths diverge as they move towards the lumen. The water chain in the broad channel is better connected than in the narrow and large channels, where disruptions in the network are observed approximately 10 Å from the OEC. In addition, the barrier for hydronium translocation is lower in the broad channel. Thus, a proton released from any location on the OEC can access all paths, but the likely exit to the lumen passes through PsbO via the broad channel.
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Affiliation(s)
- Divya Kaur
- Department of Chemistry, The Graduate Center, City University of New York, New York, NY 10016, United States; Department of Physics, City College of New York, NY 10031, United States
| | - Yingying Zhang
- Department of Physics, City College of New York, NY 10031, United States; Department of Physics, The Graduate Center of the City University of New York, New York, NY 10016, United States
| | - Krystle M Reiss
- Department of Chemistry, Yale University, New Haven, CT 06520, United States
| | - Manoj Mandal
- Department of Physics, City College of New York, NY 10031, United States
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, CT 06520, United States
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, CT 06520, United States
| | - M R Gunner
- Department of Chemistry, The Graduate Center, City University of New York, New York, NY 10016, United States; Department of Physics, City College of New York, NY 10031, United States; Department of Physics, The Graduate Center of the City University of New York, New York, NY 10016, United States.
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31
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Zahariou G, Ioannidis N, Sanakis Y, Pantazis DA. Arrested Substrate Binding Resolves Catalytic Intermediates in Higher-Plant Water Oxidation. Angew Chem Int Ed Engl 2021; 60:3156-3162. [PMID: 33030775 PMCID: PMC7898718 DOI: 10.1002/anie.202012304] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Indexed: 12/05/2022]
Abstract
Among the intermediate catalytic steps of the water-oxidizing Mn4 CaO5 cluster of photosystem II (PSII), the final metastable S3 state is critically important because it binds one substrate and precedes O2 evolution. Herein, we combine X- and Q-band EPR experiments on native and methanol-treated PSII of Spinacia oleracea and show that methanol-treated PSII preparations of the S3 state correspond to a previously uncharacterized high-spin (S=6) species. This is confirmed as a major component also in intact photosynthetic membranes, coexisting with the previously known intermediate-spin conformation (S=3). The high-spin intermediate is assigned to a water-unbound form, with a MnIV3 subunit interacting ferromagnetically via anisotropic exchange with a coordinatively unsaturated MnIV ion. These results resolve and define the structural heterogeneity of the S3 state, providing constraints on the S3 to S4 transition, on substrate identity and delivery pathways, and on the mechanism of O-O bond formation.
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Affiliation(s)
- Georgia Zahariou
- Institute of Nanoscience & Nanotechnology, NCSR “Demokritos”Athens15310Greece
| | - Nikolaos Ioannidis
- Institute of Nanoscience & Nanotechnology, NCSR “Demokritos”Athens15310Greece
| | - Yiannis Sanakis
- Institute of Nanoscience & Nanotechnology, NCSR “Demokritos”Athens15310Greece
| | - Dimitrios A. Pantazis
- Max-Planck-Institut für KohlenforschungKaiser-Wilhelm-Platz 145470Mülheim an der RuhrGermany
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32
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Exploring reaction pathways for the structural rearrangements of the Mn cluster induced by water binding in the S3 state of the oxygen evolving complex of photosystem II. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2020.112905] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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33
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Abstract
We derive a model that provides an exact solution to the substrate-water exchange kinetics in a double-conformation system and use this model to interpret recently published data for Ca2+- and Sr2+-containing PSII in the S2 state, in which the g = 2.0 and g = 4.1 conformations coexist. The component concentrations derived from the kinetic model provide an analytic description of the substrate-water exchange kinetics, allowing us to more accurately interpret the results. Based on this model and the previously reported data on the S2 state g = 2.0 conformation, we obtain the substrate-water exchange rates of the g = 4.1 conformation and the conformational change rates. Two conclusions are made from the analyses. First, contrary to previous reports, there is no significant effect of substituting Sr2+ for Ca2+ on any of the exchange rate constants. Second, the exchange rate of the slowly-exchanging water (Ws) in the S2 state g = 4.1 conformation is much faster than that in the S2 state g = 2.0 conformation. The second conclusion is consistent with the assignment of Ws to W1 or W2 bound as terminal ligands to Mn4; Mn4 has been proposed to undergo an oxidation state change from Mn(IV) in the g = 2.0 conformation to Mn(III) in the g = 4.1 conformation.
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34
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Yamaguchi K, Miyagawa K, Isobe H, Shoji M, Kawakami T, Yamanaka S. Isolobal and isospin analogy between organic and inorganic open-shell molecules—Application to oxygenation reactions by active oxygen and oxy-radicals and water oxidation in the native and artificial photosynthesis. ADVANCES IN QUANTUM CHEMISTRY 2021. [DOI: 10.1016/bs.aiq.2021.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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35
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Rodríguez I, Gautam R, Tinoco AD. Using X-ray Diffraction Techniques for Biomimetic Drug Development, Formulation, and Polymorphic Characterization. Biomimetics (Basel) 2020; 6:1. [PMID: 33396786 PMCID: PMC7838816 DOI: 10.3390/biomimetics6010001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/19/2020] [Accepted: 12/23/2020] [Indexed: 12/31/2022] Open
Abstract
Drug development is a decades-long, multibillion dollar investment that often limits itself. To decrease the time to drug approval, efforts are focused on drug targets and drug formulation for optimal biocompatibility and efficacy. X-ray structural characterization approaches have catalyzed the drug discovery and design process. Single crystal X-ray diffraction (SCXRD) reveals important structural details and molecular interactions for the manifestation of a disease or for therapeutic effect. Powder X-ray diffraction (PXRD) has provided a method to determine the different phases, purity, and stability of biological drug compounds that possess crystallinity. Recently, synchrotron sources have enabled wider access to the study of noncrystalline or amorphous solids. One valuable technique employed to determine atomic arrangements and local atom ordering of amorphous materials is the pair distribution function (PDF). PDF has been used in the study of amorphous solid dispersions (ASDs). ASDs are made up of an active pharmaceutical ingredient (API) within a drug dispersed at the molecular level in an amorphous polymeric carrier. This information is vital for appropriate formulation of a drug for stability, administration, and efficacy purposes. Natural or biomimetic products are often used as the API or the formulation agent. This review profiles the deep insights that X-ray structural techniques and associated analytical methods can offer in the development of a drug.
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Affiliation(s)
- Israel Rodríguez
- Department of Chemistry, University of Puerto Rico Río Piedras, San Juan, PR 00925, USA
| | - Ritika Gautam
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Arthur D. Tinoco
- Department of Chemistry, University of Puerto Rico Río Piedras, San Juan, PR 00925, USA
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Zahariou G, Ioannidis N, Sanakis Y, Pantazis DA. Arrested Substrate Binding Resolves Catalytic Intermediates in Higher‐Plant Water Oxidation. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202012304] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Georgia Zahariou
- Institute of Nanoscience & Nanotechnology, NCSR “Demokritos” Athens 15310 Greece
| | - Nikolaos Ioannidis
- Institute of Nanoscience & Nanotechnology, NCSR “Demokritos” Athens 15310 Greece
| | - Yiannis Sanakis
- Institute of Nanoscience & Nanotechnology, NCSR “Demokritos” Athens 15310 Greece
| | - Dimitrios A. Pantazis
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
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Mäusle SM, Abzaliyeva A, Greife P, Simon PS, Perez R, Zilliges Y, Dau H. Activation energies for two steps in the S 2→ S 3 transition of photosynthetic water oxidation from time-resolved single-frequency infrared spectroscopy. J Chem Phys 2020; 153:215101. [PMID: 33291916 DOI: 10.1063/5.0027995] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The mechanism of water oxidation by the Photosystem II (PSII) protein-cofactor complex is of high interest, but specifically, the crucial coupling of protonation dynamics to electron transfer (ET) and dioxygen chemistry remains insufficiently understood. We drove spinach-PSII membranes by nanosecond-laser flashes synchronously through the water-oxidation cycle and traced the PSII processes by time-resolved single-frequency infrared (IR) spectroscopy in the spectral range of symmetric carboxylate vibrations of protein side chains. After the collection of IR-transients from 100 ns to 1 s, we analyzed the proton-removal step in the S2 ⇒ S3 transition, which precedes the ET that oxidizes the Mn4CaOx-cluster. Around 1400 cm-1, pronounced changes in the IR-transients reflect this pre-ET process (∼40 µs at 20 °C) and the ET step (∼300 µs at 20 °C). For transients collected at various temperatures, unconstrained multi-exponential simulations did not provide a coherent set of time constants, but constraining the ET time constants to previously determined values solved the parameter correlation problem and resulted in an exceptionally high activation energy of 540 ± 30 meV for the pre-ET step. We assign the pre-ET step to deprotonation of a group that is re-protonated by accepting a proton from the substrate-water, which binds concurrently with the ET step. The analyzed IR-transients disfavor carboxylic-acid deprotonation in the pre-ET step. Temperature-dependent amplitudes suggest thermal equilibria that determine how strongly the proton-removal step is reflected in the IR-transients. Unexpectedly, the proton-removal step is only weakly reflected in the 1400 cm-1 transients of PSII core complexes of a thermophilic cyanobacterium (T. elongatus).
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Affiliation(s)
- Sarah M Mäusle
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Aiganym Abzaliyeva
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Paul Greife
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Philipp S Simon
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Rebeca Perez
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Yvonne Zilliges
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Holger Dau
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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38
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Light-driven formation of manganese oxide by today's photosystem II supports evolutionarily ancient manganese-oxidizing photosynthesis. Nat Commun 2020; 11:6110. [PMID: 33257675 PMCID: PMC7705724 DOI: 10.1038/s41467-020-19852-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 11/02/2020] [Indexed: 11/10/2022] Open
Abstract
Water oxidation and concomitant dioxygen formation by the manganese-calcium cluster of oxygenic photosynthesis has shaped the biosphere, atmosphere, and geosphere. It has been hypothesized that at an early stage of evolution, before photosynthetic water oxidation became prominent, light-driven formation of manganese oxides from dissolved Mn(2+) ions may have played a key role in bioenergetics and possibly facilitated early geological manganese deposits. Here we report the biochemical evidence for the ability of photosystems to form extended manganese oxide particles. The photochemical redox processes in spinach photosystem-II particles devoid of the manganese-calcium cluster are tracked by visible-light and X-ray spectroscopy. Oxidation of dissolved manganese ions results in high-valent Mn(III,IV)-oxide nanoparticles of the birnessite type bound to photosystem II, with 50-100 manganese ions per photosystem. Having shown that even today’s photosystem II can form birnessite-type oxide particles efficiently, we propose an evolutionary scenario, which involves manganese-oxide production by ancestral photosystems, later followed by down-sizing of protein-bound manganese-oxide nanoparticles to finally yield today’s catalyst of photosynthetic water oxidation. Photosynthetic formation of manganese (Mn) oxides from dissolved Mn ions was proposed to occur in ancestral photosystems before oxygenic photosynthesis evolved. Here, the authors provide evidence for this hypothesis by showing that photosystem II devoid of the Mn cluster oxidises Mn ions leading to formation of Mn-oxide nanoparticles.
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Bozal-Ginesta C, Mesa CA, Eisenschmidt A, Francàs L, Shankar RB, Antón-García D, Warnan J, Willkomm J, Reynal A, Reisner E, Durrant JR. Charge accumulation kinetics in multi-redox molecular catalysts immobilised on TiO 2. Chem Sci 2020; 12:946-959. [PMID: 34163861 PMCID: PMC8178996 DOI: 10.1039/d0sc04344c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/07/2020] [Indexed: 11/29/2022] Open
Abstract
Multi-redox catalysis requires the accumulation of more than one charge carrier and is crucial for solar energy conversion into fuels and valuable chemicals. In photo(electro)chemical systems, however, the necessary accumulation of multiple, long-lived charges is challenged by recombination with their counterparts. Herein, we investigate charge accumulation in two model multi-redox molecular catalysts for proton and CO2 reduction attached onto mesoporous TiO2 electrodes. Transient absorption spectroscopy and spectroelectrochemical techniques have been employed to study the kinetics of photoinduced electron transfer from the TiO2 to the molecular catalysts in acetonitrile, with triethanolamine as the hole scavenger. At high light intensities, we detect charge accumulation in the millisecond timescale in the form of multi-reduced species. The redox potentials of the catalysts and the capacity of TiO2 to accumulate electrons play an essential role in the charge accumulation process at the molecular catalyst. Recombination of reduced species with valence band holes in TiO2 is observed to be faster than microseconds, while electron transfer from multi-reduced species to the conduction band or the electrolyte occurs in the millisecond timescale. Finally, under light irradiation, we show how charge accumulation on the catalyst is regulated as a function of the applied bias and the excitation light intensity.
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Affiliation(s)
- Carlota Bozal-Ginesta
- Department of Chemistry, Centre for Processable Electronics, Imperial College London 80 Wood Lane London W12 0BZ UK
| | - Camilo A Mesa
- Department of Chemistry, Centre for Processable Electronics, Imperial College London 80 Wood Lane London W12 0BZ UK
| | - Annika Eisenschmidt
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Laia Francàs
- Department of Chemistry, Centre for Processable Electronics, Imperial College London 80 Wood Lane London W12 0BZ UK
| | - Ravi B Shankar
- Department of Chemical Engineering, Imperial College London Exhibition Road London SW7 2AZ UK
| | - Daniel Antón-García
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Julien Warnan
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Janina Willkomm
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Anna Reynal
- Department of Chemistry, Centre for Processable Electronics, Imperial College London 80 Wood Lane London W12 0BZ UK
| | - Erwin Reisner
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - James R Durrant
- Department of Chemistry, Centre for Processable Electronics, Imperial College London 80 Wood Lane London W12 0BZ UK
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de Lichtenberg C, Avramov AP, Zhang M, Mamedov F, Burnap RL, Messinger J. The D1-V185N mutation alters substrate water exchange by stabilizing alternative structures of the Mn 4Ca-cluster in photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148319. [PMID: 32979346 DOI: 10.1016/j.bbabio.2020.148319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 09/15/2020] [Accepted: 09/19/2020] [Indexed: 11/30/2022]
Abstract
In photosynthesis, the oxygen-evolving complex (OEC) of the pigment-protein complex photosystem II (PSII) orchestrates the oxidation of water. Introduction of the V185N mutation into the D1 protein was previously reported to drastically slow O2-release and strongly perturb the water network surrounding the Mn4Ca cluster. Employing time-resolved membrane inlet mass spectrometry, we measured here the H218O/H216O-exchange kinetics of the fast (Wf) and slow (Ws) exchanging substrate waters bound in the S1, S2 and S3 states to the Mn4Ca cluster of PSII core complexes isolated from wild type and D1-V185N strains of Synechocystis sp. PCC 6803. We found that the rate of exchange for Ws was increased in the S1 and S2 states, while both Wf and Ws exchange rates were decreased in the S3 state. Additionally, we used EPR spectroscopy to characterize the Mn4Ca cluster and its interaction with the redox active D1-Tyr161 (YZ). In the S2 state, we observed a greatly diminished multiline signal in the V185N-PSII that could be recovered by addition of ammonia. The split signal in the S1 state was not affected, while the split signal in the S3 state was absent in the D1-V185N mutant. These findings are rationalized by the proposal that the N185 residue stabilizes the binding of an additional water-derived ligand at the Mn1 site of the Mn4Ca cluster via hydrogen bonding. Implications for the sites of substrate water binding are discussed.
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Affiliation(s)
- Casper de Lichtenberg
- Department of Chemistry, Umeå University, Linnaeus väg 6 (KBC huset), SE-901 87 Umeå, Sweden; Molecular Biomimetics, Department of Chemistry - Ångström, Uppsala University, POB 523, SE-75120 Uppsala, Sweden
| | - Anton P Avramov
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, United States
| | - Minquan Zhang
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, United States
| | - Fikret Mamedov
- Molecular Biomimetics, Department of Chemistry - Ångström, Uppsala University, POB 523, SE-75120 Uppsala, Sweden
| | - Robert L Burnap
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK 74078, United States
| | - Johannes Messinger
- Department of Chemistry, Umeå University, Linnaeus väg 6 (KBC huset), SE-901 87 Umeå, Sweden; Molecular Biomimetics, Department of Chemistry - Ångström, Uppsala University, POB 523, SE-75120 Uppsala, Sweden.
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41
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Kim CJ, Debus RJ. Roles of D1-Glu189 and D1-Glu329 in O2 Formation by the Water-Splitting Mn4Ca Cluster in Photosystem II. Biochemistry 2020; 59:3902-3917. [DOI: 10.1021/acs.biochem.0c00541] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christopher J. Kim
- Department of Biochemistry, University of California, Riverside, California 92521, United States
| | - Richard J. Debus
- Department of Biochemistry, University of California, Riverside, California 92521, United States
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42
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Recent advances in heterogeneous Mn-based electrocatalysts toward biological photosynthetic Mn4Ca cluster. Catal Today 2020. [DOI: 10.1016/j.cattod.2016.12.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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43
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Cox N, Pantazis DA, Lubitz W. Current Understanding of the Mechanism of Water Oxidation in Photosystem II and Its Relation to XFEL Data. Annu Rev Biochem 2020; 89:795-820. [DOI: 10.1146/annurev-biochem-011520-104801] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The investigation of water oxidation in photosynthesis has remained a central topic in biochemical research for the last few decades due to the importance of this catalytic process for technological applications. Significant progress has been made following the 2011 report of a high-resolution X-ray crystallographic structure resolving the site of catalysis, a protein-bound Mn4CaOxcomplex, which passes through ≥5 intermediate states in the water-splitting cycle. Spectroscopic techniques complemented by quantum chemical calculations aided in understanding the electronic structure of the cofactor in all (detectable) states of the enzymatic process. Together with isotope labeling, these techniques also revealed the binding of the two substrate water molecules to the cluster. These results are described in the context of recent progress using X-ray crystallography with free-electron lasers on these intermediates. The data are instrumental for developing a model for the biological water oxidation cycle.
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Affiliation(s)
- Nicholas Cox
- Research School of Chemistry, The Australian National University, Canberra ACT 2601, Australia
| | | | - Wolfgang Lubitz
- Max-Planck-Institut für Chemische Energiekonversion, 45470 Mülheim an der Ruhr, Germany
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44
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Shimada Y, Kitajima-Ihara T, Nagao R, Noguchi T. Role of the O4 Channel in Photosynthetic Water Oxidation as Revealed by Fourier Transform Infrared Difference and Time-Resolved Infrared Analysis of the D1-S169A Mutant. J Phys Chem B 2020; 124:1470-1480. [DOI: 10.1021/acs.jpcb.9b11946] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Yuichiro Shimada
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Tomomi Kitajima-Ihara
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Ryo Nagao
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Takumi Noguchi
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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Melder J, Bogdanoff P, Zaharieva I, Fiechter S, Dau H, Kurz P. Water-Oxidation Electrocatalysis by Manganese Oxides: Syntheses, Electrode Preparations, Electrolytes and Two Fundamental Questions. Z PHYS CHEM 2020. [DOI: 10.1515/zpch-2019-1491] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Abstract
The efficient catalysis of the four-electron oxidation of water to molecular oxygen is a central challenge for the development of devices for the production of solar fuels. This is equally true for artificial leaf-type structures and electrolyzer systems. Inspired by the oxygen evolving complex of Photosystem II, the biological catalyst for this reaction, scientists around the globe have investigated the possibility to use manganese oxides (“MnOx”) for this task. This perspective article will look at selected examples from the last about 10 years of research in this field. At first, three aspects are addressed in detail which have emerged as crucial for the development of efficient electrocatalysts for the anodic oxygen evolution reaction (OER): (1) the structure and composition of the “MnOx” is of central importance for catalytic performance and it seems that amorphous, MnIII/IV oxides with layered or tunnelled structures are especially good choices; (2) the type of support material (e.g. conducting oxides or nanostructured carbon) as well as the methods used to immobilize the MnOx catalysts on them greatly influence OER overpotentials, current densities and long-term stabilities of the electrodes and (3) when operating MnOx-based water-oxidizing anodes in electrolyzers, it has often been observed that the electrocatalytic performance is also largely dependent on the electrolyte’s composition and pH and that a number of equilibria accompany the catalytic process, resulting in “adaptive changes” of the MnOx material over time. Overall, it thus has become clear over the last years that efficient and stable water-oxidation electrolysis by manganese oxides can only be achieved if at least four parameters are optimized in combination: the oxide catalyst itself, the immobilization method, the catalyst support and last but not least the composition of the electrolyte. Furthermore, these parameters are not only important for the electrode optimization process alone but must also be considered if different electrode types are to be compared with each other or with literature values from literature. Because, as without their consideration it is almost impossible to draw the right scientific conclusions. On the other hand, it currently seems unlikely that even carefully optimized MnOx anodes will ever reach the superb OER rates observed for iridium, ruthenium or nickel-iron oxide anodes in acidic or alkaline solutions, respectively. So at the end of the article, two fundamental questions will be addressed: (1) are there technical applications where MnOx materials could actually be the first choice as OER electrocatalysts? and (2) do the results from the last decade of intensive research in this field help to solve a puzzle already formulated in 2008: “Why did nature choose manganese to make oxygen?”.
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Affiliation(s)
- Jens Melder
- Institut für Anorganische und Analytische Chemie und Freiburger Materialforschungszentrum (FMF) , Albert-Ludwigs-Universität Freiburg , Albertstraße 21, 79104 Freiburg , Germany
| | - Peter Bogdanoff
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institute for Solar Fuels , 14109 Berlin , Germany
| | - Ivelina Zaharieva
- Freie Universität Berlin, Fachbereich Physik , Arnimallee 14, 14195 Berlin , Germany
| | - Sebastian Fiechter
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institute for Solar Fuels , 14109 Berlin , Germany
| | - Holger Dau
- Freie Universität Berlin, Fachbereich Physik , Arnimallee 14, 14195 Berlin , Germany
| | - Philipp Kurz
- Institut für Anorganische und Analytische Chemie und Freiburger Materialforschungszentrum (FMF) , Albert-Ludwigs-Universität Freiburg , Albertstraße 21, 79104 Freiburg , Germany
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46
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Zhang HT, Zhang MT. The Application of Pincer Ligand in Catalytic Water Splitting. TOP ORGANOMETAL CHEM 2020. [DOI: 10.1007/3418_2020_71] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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47
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de Lichtenberg C, Messinger J. Substrate water exchange in the S2 state of photosystem II is dependent on the conformation of the Mn4Ca cluster. Phys Chem Chem Phys 2020; 22:12894-12908. [DOI: 10.1039/d0cp01380c] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The structural flexibility of the Mn4Ca cluster in photosystem II supports the exchange of the central O5 bridge.
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49
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Samanta D, Saha P, Ghosh P. Proton-Coupled Oxidation of Aldimines and Stabilization of H-Bonded Phenoxyl Radical-Phenol Skeletons. Inorg Chem 2019; 58:15060-15077. [DOI: 10.1021/acs.inorgchem.9b01568] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Debasish Samanta
- Department of Chemistry, R. K. Mission Residential College, Narendrapur, Kolkata 700103, India
| | - Pinaki Saha
- Department of Chemistry, R. K. Mission Residential College, Narendrapur, Kolkata 700103, India
| | - Prasanta Ghosh
- Department of Chemistry, R. K. Mission Residential College, Narendrapur, Kolkata 700103, India
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50
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Lubitz W, Chrysina M, Cox N. Water oxidation in photosystem II. PHOTOSYNTHESIS RESEARCH 2019; 142:105-125. [PMID: 31187340 PMCID: PMC6763417 DOI: 10.1007/s11120-019-00648-3] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 05/20/2019] [Indexed: 05/18/2023]
Abstract
Biological water oxidation, performed by a single enzyme, photosystem II, is a central research topic not only in understanding the photosynthetic apparatus but also for the development of water splitting catalysts for technological applications. Great progress has been made in this endeavor following the report of a high-resolution X-ray crystallographic structure in 2011 resolving the cofactor site (Umena et al. in Nature 473:55-60, 2011), a tetra-manganese calcium complex. The electronic properties of the protein-bound water oxidizing Mn4OxCa complex are crucial to understand its catalytic activity. These properties include: its redox state(s) which are tuned by the protein matrix, the distribution of the manganese valence and spin states and the complex interactions that exist between the four manganese ions. In this short review we describe how magnetic resonance techniques, particularly EPR, complemented by quantum chemical calculations, have played an important role in understanding the electronic structure of the cofactor. Together with isotope labeling, these techniques have also been instrumental in deciphering the binding of the two substrate water molecules to the cluster. These results are briefly described in the context of the history of biological water oxidation with special emphasis on recent work using time resolved X-ray diffraction with free electron lasers. It is shown that these data are instrumental for developing a model of the biological water oxidation cycle.
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Affiliation(s)
- Wolfgang Lubitz
- Max-Planck-Institut für Chemische Energiekonversion, Mülheim/Ruhr, Germany
| | - Maria Chrysina
- Max-Planck-Institut für Chemische Energiekonversion, Mülheim/Ruhr, Germany
| | - Nicholas Cox
- Research School of Chemistry, The Australian National University, Canberra, Australia
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