1
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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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2
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Pavlou A, Styring S, Mamedov F. The S 1 to S 2 and S 2 to S 3 state transitions in plant photosystem II: relevance to the functional and structural heterogeneity of the water oxidizing complex. PHOTOSYNTHESIS RESEARCH 2024:10.1007/s11120-024-01096-4. [PMID: 38662327 DOI: 10.1007/s11120-024-01096-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 03/18/2024] [Indexed: 04/26/2024]
Abstract
In Photosystem II, light-induced water splitting occurs via the S state cycle of the CaMn4O5-cluster. To understand the role of various possible conformations of the CaMn4O5-cluster in this process, the temperature dependence of the S1 → S2 and S2 → S3 state transitions, induced by saturating laser flashes, was studied in spinach photosystem II membrane preparations under different conditions. The S1 → S2 transition temperature dependence was shown to be much dependent on the type of the cryoprotectant and presence of 3.5% methanol, resulting in the variation of transition half-inhibition temperature by 50 K. No similar effect was observed for the S2 → S3 state transition, for which we also show that both the low spin g = 2.0 multiline and high spin g = 4.1 EPR configurations of the S2 state advance with similar efficiency to the S3 state, both showing a transition half-inhibition temperature of 240 K. This was further confirmed by following the appearance of the Split S3 EPR signal. The results are discussed in relevance to the functional and structural heterogeneity of the water oxidizing complex intermediates in photosystem II.
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Affiliation(s)
- Andrea Pavlou
- Molecular Biomimetics, Department of Chemistry-Ångström, Uppsala University, P.O. Box 523, 751 20, Uppsala, Sweden
| | - Stenbjörn Styring
- Molecular Biomimetics, Department of Chemistry-Ångström, Uppsala University, P.O. Box 523, 751 20, Uppsala, Sweden
| | - Fikret Mamedov
- Molecular Biomimetics, Department of Chemistry-Ångström, Uppsala University, P.O. Box 523, 751 20, Uppsala, Sweden.
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3
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Chrysina M, Drosou M, Castillo RG, Reus M, Neese F, Krewald V, Pantazis DA, DeBeer S. Nature of S-States in the Oxygen-Evolving Complex Resolved by High-Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy. J Am Chem Soc 2023; 145:25579-25594. [PMID: 37970825 PMCID: PMC10690802 DOI: 10.1021/jacs.3c06046] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/13/2023] [Accepted: 10/13/2023] [Indexed: 11/19/2023]
Abstract
Photosystem II, the water splitting enzyme of photosynthesis, utilizes the energy of sunlight to drive the four-electron oxidation of water to dioxygen at the oxygen-evolving complex (OEC). The OEC harbors a Mn4CaO5 cluster that cycles through five oxidation states Si (i = 0-4). The S3 state is the last metastable state before the O2 evolution. Its electronic structure and nature of the S2 → S3 transition are key topics of persisting controversy. Most spectroscopic studies suggest that the S3 state consists of four Mn(IV) ions, compared to the Mn(III)Mn(IV)3 of the S2 state. However, recent crystallographic data have received conflicting interpretations, suggesting either metal- or ligand-based oxidation, the latter leading to an oxyl radical or a peroxo moiety in the S3 state. Herein, we utilize high-energy resolution fluorescence detected (HERFD) X-ray absorption spectroscopy to obtain a highly resolved description of the Mn K pre-edge region for all S-states, paying special attention to use chemically unperturbed S3 state samples. In combination with quantum chemical calculations, we achieve assignment of specific spectroscopic features to geometric and electronic structures for all S-states. These data are used to confidently discriminate between the various suggestions concerning the electronic structure and the nature of oxidation events in all observable catalytic intermediates of the OEC. Our results do not support the presence of either peroxo or oxyl in the active configuration of the S3 state. This establishes Mn-centered storage of oxidative equivalents in all observable catalytic transitions and constrains the onset of the O-O bond formation until after the final light-driven oxidation event.
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Affiliation(s)
- Maria Chrysina
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstr. 34-36, Mülheim
an der Ruhr 45470, Germany
- Institute
of Nanoscience & Nanotechnology, NCSR “Demokritos”, Athens 15310, Greece
| | - Maria Drosou
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Rebeca G. Castillo
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstr. 34-36, Mülheim
an der Ruhr 45470, Germany
- Laboratory
of Ultrafast Spectroscopy (LSU) and Lausanne Centre for Ultrafast
Science, École Polytechnique Fédérale
de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Michael Reus
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstr. 34-36, Mülheim
an der Ruhr 45470, Germany
| | - Frank Neese
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Vera Krewald
- Department
of Chemistry, Technical University of Darmstadt, Peter-Grünberg-Str. 4, Darmstadt 64287, Germany
| | - Dimitrios A. Pantazis
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
| | - Serena DeBeer
- Max-Planck-Institut
für Chemische Energiekonversion, Stiftstr. 34-36, Mülheim
an der Ruhr 45470, Germany
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4
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Pavlou A, Mokvist F, Styring S, Mamedov F. Far-red photosynthesis: Two charge separation pathways exist in plant Photosystem II reaction center. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148994. [PMID: 37355002 DOI: 10.1016/j.bbabio.2023.148994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/09/2023] [Accepted: 06/15/2023] [Indexed: 06/26/2023]
Abstract
An alternative charge separation pathway in Photosystem II under the far-red light was proposed by us on the basis of electron transfer properties at 295 K and 5 K. Here we extend these studies to the temperature range of 77-295 K with help of electron paramagnetic resonance spectroscopy. Induction of the S2 state multiline signal, oxidation of Cytochrome b559 and ChlorophyllZ was studied in Photosystem II membrane preparations from spinach after application of a laser flashes in visible (532 nm) or far-red (730-750 nm) spectral regions. Temperature dependence of the S2 state signal induction after single flash at 730-750 nm (Tinhibition ~ 240 K) was found to be different than that at 532 nm (Tinhibition ~ 157 K). No contaminant oxidation of the secondary electron donors cytochrome b559 or chlorophyllZ was observed. Photoaccumulation experiments with extensive flashing at 77 K showed similar results, with no or very little induction of the secondary electron donors. Thus, the partition ratio defined as (yield of YZ/CaMn4O5-cluster oxidation):(yield of Cytb559/ChlZ/CarD2 oxidation) was found to be 0.4 at under visible light and 1.7 at under far-red light at 77 K. Our data indicate that different products of charge separation after far-red light exists in the wide temperature range which further support the model of the different primary photochemistry in Photosystem II with localization of hole on the ChlD1 molecule.
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Affiliation(s)
- Andrea Pavlou
- Molecular Biomimetics, Department of Chemistry-Ångström, Uppsala University, P.O. Box 523, 751 20 Uppsala, Sweden
| | - Fredrik Mokvist
- Molecular Biomimetics, Department of Chemistry-Ångström, Uppsala University, P.O. Box 523, 751 20 Uppsala, Sweden
| | - Stenbjörn Styring
- Molecular Biomimetics, Department of Chemistry-Ångström, Uppsala University, P.O. Box 523, 751 20 Uppsala, Sweden
| | - Fikret Mamedov
- Molecular Biomimetics, Department of Chemistry-Ångström, Uppsala University, P.O. Box 523, 751 20 Uppsala, Sweden.
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5
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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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6
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Mattila H, Mishra S, Tyystjärvi T, Tyystjärvi E. Singlet oxygen production by photosystem II is caused by misses of the oxygen evolving complex. THE NEW PHYTOLOGIST 2023; 237:113-125. [PMID: 36161283 PMCID: PMC10092662 DOI: 10.1111/nph.18514] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 09/10/2022] [Indexed: 06/12/2023]
Abstract
Singlet oxygen (1 O2 ) is a harmful species that functions also as a signaling molecule. In chloroplasts, 1 O2 is produced via charge recombination reactions in photosystem II, but which recombination pathway(s) produce triplet Chl and 1 O2 remains open. Furthermore, the role of 1 O2 in photoinhibition is not clear. We compared temperature dependences of 1 O2 production, photoinhibition, and recombination pathways. 1 O2 production by pumpkin thylakoids increased from -2 to +35°C, ruling out recombination of the primary charge pair as a main contributor. S2 QA - or S2 QB - recombination pathways, in turn, had too steep temperature dependences. Instead, the temperature dependence of 1 O2 production matched that of misses (failures of the oxygen (O2 ) evolving complex to advance an S-state). Photoinhibition in vitro and in vivo (also in Synechocystis), and in the presence or absence of O2 , had the same temperature dependence, but ultraviolet (UV)-radiation-caused photoinhibition showed a weaker temperature response. We suggest that the miss-associated recombination of P680 + QA - is the main producer of 1 O2 . Our results indicate three parallel photoinhibition mechanisms. The manganese mechanism dominates in UV radiation but also functions in white light. Mechanisms that depend on light absorption by Chls, having 1 O2 or long-lived P680 + as damaging agents, dominate in red light.
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Affiliation(s)
- Heta Mattila
- Department of Life Technologies/Molecular Plant BiologyUniversity of TurkuFI‐20014TurkuFinland
| | - Sujata Mishra
- Department of Life Technologies/Molecular Plant BiologyUniversity of TurkuFI‐20014TurkuFinland
| | - Taina Tyystjärvi
- Department of Life Technologies/Molecular Plant BiologyUniversity of TurkuFI‐20014TurkuFinland
| | - Esa Tyystjärvi
- Department of Life Technologies/Molecular Plant BiologyUniversity of TurkuFI‐20014TurkuFinland
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7
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Han G, Chernev P, Styring S, Messinger J, Mamedov F. Molecular basis for turnover inefficiencies (misses) during water oxidation in photosystem II. Chem Sci 2022; 13:8667-8678. [PMID: 35974765 PMCID: PMC9337725 DOI: 10.1039/d2sc00854h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 07/04/2022] [Indexed: 11/24/2022] Open
Abstract
Photosynthesis stores solar light as chemical energy and efficiency of this process is highly important. The electrons required for CO2 reduction are extracted from water in a reaction driven by light-induced charge separations in the Photosystem II reaction center and catalyzed by the CaMn4O5-cluster. This cyclic process involves five redox intermediates known as the S0–S4 states. In this study, we quantify the flash-induced turnover efficiency of each S state by electron paramagnetic resonance spectroscopy. Measurements were performed in photosystem II membrane preparations from spinach in the presence of an exogenous electron acceptor at selected temperatures between −10 °C and +20 °C and at flash frequencies of 1.25, 5 and 10 Hz. The results show that at optimal conditions the turnover efficiencies are limited by reactions occurring in the water oxidizing complex, allowing the extraction of their S state dependence and correlating low efficiencies to structural changes and chemical events during the reaction cycle. At temperatures 10 °C and below, the highest efficiency (i.e. lowest miss parameter) was found for the S1 → S2 transition, while the S2 → S3 transition was least efficient (highest miss parameter) over the whole temperature range. These electron paramagnetic resonance results were confirmed by measurements of flash-induced oxygen release patterns in thylakoid membranes and are explained on the basis of S state dependent structural changes at the CaMn4O5-cluster that were determined recently by femtosecond X-ray crystallography. Thereby, possible “molecular errors” connected to the e− transfer, H+ transfer, H2O binding and O2 release are identified. Temperature dependence of the transition inefficiencies (misses) for the water oxidation process in photosystem II were studied by EPR spectroscopy and are explained on the basis of S state dependent structural changes at the CaMn4O5-cluster.![]()
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Affiliation(s)
- Guangye Han
- Molecular Biomimetics, Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 751 20 Uppsala, Sweden
| | - Petko Chernev
- Molecular Biomimetics, Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 751 20 Uppsala, Sweden
| | - Stenbjörn Styring
- Molecular Biomimetics, Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 751 20 Uppsala, Sweden
| | - Johannes Messinger
- Molecular Biomimetics, Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 751 20 Uppsala, Sweden
- Department of Chemistry, Umeå University, 901 87 Umeå, Sweden
| | - Fikret Mamedov
- Molecular Biomimetics, Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 751 20 Uppsala, Sweden
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8
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Cavaletto SM, Nascimento DR, Zhang Y, Govind N, Mukamel S. Resonant Stimulated X-ray Raman Spectroscopy of Mixed-Valence Manganese Complexes. J Phys Chem Lett 2021; 12:5925-5931. [PMID: 34156863 DOI: 10.1021/acs.jpclett.1c01190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Resonant stimulated X-ray Raman spectroscopy of the bimetallic [MnIIIMnIV(μ-O)2(μ-OAC)(tacn)2]2+ manganese complex is investigated in a simulation study. Essential biological processes, including water oxidation in photosynthesis, involve charge transfer between manganese sites of different oxidation states. We study a prototypical binuclear mixed-valence transition-metal complex with two Mn atoms in different oxidation states surrounded by ligand structures and employ a pump-probe sequence of resonant X-ray Raman excitations to follow the charge transfer occurring in the molecule. This allows us to generate and monitor valence-electron wave packets at selected regions in the molecule by exploiting element-specific core-excited states. A two-color protocol is presented, with pump and probe pulses tuned to the Mn and N K-edges. A natural orbital decomposition allows the visualization of the electron dynamics underlying the signal.
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Affiliation(s)
- Stefano M Cavaletto
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697, United States
| | - Daniel R Nascimento
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Yu Zhang
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Niranjan Govind
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Shaul Mukamel
- Department of Chemistry and Department of Physics and Astronomy, University of California, Irvine, California 92697, United States
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9
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Pham LV, Janna Olmos JD, Chernev P, Kargul J, Messinger J. Unequal misses during the flash-induced advancement of photosystem II: effects of the S state and acceptor side cycles. PHOTOSYNTHESIS RESEARCH 2019; 139:93-106. [PMID: 30191436 PMCID: PMC6373315 DOI: 10.1007/s11120-018-0574-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 08/03/2018] [Indexed: 05/17/2023]
Abstract
Photosynthetic water oxidation is catalyzed by the oxygen-evolving complex (OEC) in photosystem II (PSII). This process is energetically driven by light-induced charge separation in the reaction center of PSII, which leads to a stepwise accumulation of oxidizing equivalents in the OEC (Si states, i = 0-4) resulting in O2 evolution after each fourth flash, and to the reduction of plastoquinone to plastoquinol on the acceptor side of PSII. However, the Si-state advancement is not perfect, which according to the Kok model is described by miss-hits (misses). These may be caused by redox equilibria or kinetic limitations on the donor (OEC) or the acceptor side. In this study, we investigate the effects of individual S state transitions and of the quinone acceptor side on the miss parameter by analyzing the flash-induced oxygen evolution patterns and the S2, S3 and S0 state lifetimes in thylakoid samples of the extremophilic red alga Cyanidioschyzon merolae. The data are analyzed employing a global fit analysis and the results are compared to the data obtained previously for spinach thylakoids. These two organisms were selected, because the redox potential of QA/QA- in PSII is significantly less negative in C. merolae (Em = - 104 mV) than in spinach (Em = - 163 mV). This significant difference in redox potential was expected to allow the disentanglement of acceptor and donor side effects on the miss parameter. Our data indicate that, at slightly acidic and neutral pH values, the Em of QA-/QA plays only a minor role for the miss parameter. By contrast, the increased energy gap for the backward electron transfer from QA- to Pheo slows down the charge recombination reaction with the S3 and S2 states considerably. In addition, our data support the concept that the S2 → S3 transition is the least efficient step during the oxidation of water to molecular oxygen in the Kok cycle of PSII.
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Affiliation(s)
- Long Vo Pham
- Department of Chemistry - Ångström, Uppsala University, Lägerhyddsvägen 1, 75120, Uppsala, Sweden
| | - Julian David Janna Olmos
- Solar Fuels Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097, Warsaw, Poland
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Petko Chernev
- Department of Chemistry - Ångström, Uppsala University, Lägerhyddsvägen 1, 75120, Uppsala, Sweden
| | - Joanna Kargul
- Solar Fuels Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097, Warsaw, Poland.
| | - Johannes Messinger
- Department of Chemistry - Ångström, Uppsala University, Lägerhyddsvägen 1, 75120, Uppsala, Sweden.
- Department of Chemistry, Chemistry Biology Center (KBC), Umeå University, Linnaeus väg 6, 901 87, Umeå, Sweden.
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10
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Ananyev G, Roy-Chowdhury S, Gates C, Fromme P, Dismukes GC. The Catalytic Cycle of Water Oxidation in Crystallized Photosystem II Complexes: Performance and Requirements for Formation of Intermediates. ACS Catal 2019. [DOI: 10.1021/acscatal.8b04513] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
| | - Shatabdi Roy-Chowdhury
- Biodesign Center for Applied Structural Discovery, The Biodesign Institute and School of Molecular Sciences Arizona State University, Tempe, Arizona 85287, United States
| | | | - Petra Fromme
- Biodesign Center for Applied Structural Discovery, The Biodesign Institute and School of Molecular Sciences Arizona State University, Tempe, Arizona 85287, United States
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11
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Gates C, Ananyev G, Dismukes GC. The strontium inorganic mutant of the water oxidizing center (CaMn4O5) of PSII improves WOC efficiency but slows electron flux through the terminal acceptors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1550-1560. [DOI: 10.1016/j.bbabio.2016.06.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/26/2016] [Accepted: 06/10/2016] [Indexed: 01/26/2023]
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12
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Ananyev G, Gates C, Dismukes GC. The Oxygen quantum yield in diverse algae and cyanobacteria is controlled by partitioning of flux between linear and cyclic electron flow within photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1380-1391. [PMID: 27117512 DOI: 10.1016/j.bbabio.2016.04.056] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 04/20/2016] [Accepted: 04/21/2016] [Indexed: 01/07/2023]
Abstract
We have measured flash-induced oxygen quantum yields (O2-QYs) and primary charge separation (Chl variable fluorescence yield, Fv/Fm) in vivo among phylogenetically diverse microalgae and cyanobacteria. Higher O2-QYs can be attained in cells by releasing constraints on charge transfer at the Photosystem II (PSII) acceptor side by adding membrane-permeable benzoquinone (BQ) derivatives that oxidize plastosemiquinone QB(-) and QBH2. This method allows uncoupling PSII turnover from its natural regulation in living cells, without artifacts of isolating PSII complexes. This approach reveals different extents of regulation across species, controlled at the QB(-) acceptor site. Arthrospira maxima is confirmed as the most efficient PSII-WOC (water oxidizing complex) and exhibits the least regulation of flux. Thermosynechococcus elongatus exhibits an O2-QY of 30%, suggesting strong downregulation. WOC cycle simulations with the most accurate model (VZAD) show that a light-driven backward transition (net addition of an electron to the WOC, distinct from recombination) occurs in up to 25% of native PSIIs in the S2 and S3 states, while adding BQ prevents backward transitions and increases the lifetime of S2 and S3 by 10-fold. Backward transitions occur in PSIIs that have plastosemiquinone radicals in the QB site and are postulated to be physiologically regulated pathways for storing light energy as proton gradient through direct PSII-cyclic electron flow (PSII-CEF). PSII-CEF is independent of classical PSI/cyt-b6f-CEF and provides an alternative proton translocation pathway for energy conversion. PSII-CEF enables variable fluxes between linear and cyclic electron pathways, thus accommodating species-dependent needs for redox and ion-gradient energy sources powered by a single photosystem.
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Affiliation(s)
- Gennady Ananyev
- The Waksman Institute of Microbiology and the Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, United States
| | - Colin Gates
- The Waksman Institute of Microbiology and the Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, United States
| | - G Charles Dismukes
- The Waksman Institute of Microbiology and the Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854, United States.
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13
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Pham LV, Messinger J. Probing S-state advancements and recombination pathways in photosystem II with a global fit program for flash-induced oxygen evolution pattern. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:848-59. [PMID: 27033305 DOI: 10.1016/j.bbabio.2016.03.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/30/2016] [Accepted: 03/12/2016] [Indexed: 12/22/2022]
Abstract
The oxygen-evolving complex (OEC) in photosystem II catalyzes the oxidation of water to molecular oxygen. Four decades ago, measurements of flash-induced oxygen evolution have shown that the OEC steps through oxidation states S(0), S(1), S(2), S(3) and S(4) before O(2) is released and the S(0) state is reformed. The light-induced transitions between these states involve misses and double hits. While it is widely accepted that the miss parameter is S state dependent and may be further modulated by the oxidation state of the acceptor side, the traditional way of analyzing each flash-induced oxygen evolution pattern (FIOP) individually did not allow using enough free parameters to thoroughly test this proposal. Furthermore, this approach does not allow assessing whether the presently known recombination processes in photosystem II fully explain all measured oxygen yields during Si state lifetime measurements. Here we present a global fit program that simultaneously fits all flash-induced oxygen yields of a standard FIOP (2 Hz flash frequency) and of 11-18 FIOPs each obtained while probing the S(0), S(2) and S(3) state lifetimes in spinach thylakoids at neutral pH. This comprehensive data treatment demonstrates the presence of a very slow phase of S(2) decay, in addition to the commonly discussed fast and slow reduction of S(2) by YD and QB(-), respectively. Our data support previous suggestions that the S(0)→S(1) and S(1)→S(2) transitions involve low or no misses, while high misses occur in the S(2)→S(3) or S(3)→S(0) transitions.
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Affiliation(s)
- Long Vo Pham
- Department of Chemistry, Chemistry Biology Center (KBC), Umeå University, Linnaeus väg 6, SE-901 87 Umeå, Sweden
| | - Johannes Messinger
- Department of Chemistry, Chemistry Biology Center (KBC), Umeå University, Linnaeus väg 6, SE-901 87 Umeå, Sweden.
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14
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Serial time-resolved crystallography of photosystem II using a femtosecond X-ray laser. Nature 2014; 513:261-5. [PMID: 25043005 DOI: 10.1038/nature13453] [Citation(s) in RCA: 315] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 05/04/2014] [Indexed: 01/17/2023]
Abstract
Photosynthesis, a process catalysed by plants, algae and cyanobacteria converts sunlight to energy thus sustaining all higher life on Earth. Two large membrane protein complexes, photosystem I and II (PSI and PSII), act in series to catalyse the light-driven reactions in photosynthesis. PSII catalyses the light-driven water splitting process, which maintains the Earth's oxygenic atmosphere. In this process, the oxygen-evolving complex (OEC) of PSII cycles through five states, S0 to S4, in which four electrons are sequentially extracted from the OEC in four light-driven charge-separation events. Here we describe time resolved experiments on PSII nano/microcrystals from Thermosynechococcus elongatus performed with the recently developed technique of serial femtosecond crystallography. Structures have been determined from PSII in the dark S1 state and after double laser excitation (putative S3 state) at 5 and 5.5 Å resolution, respectively. The results provide evidence that PSII undergoes significant conformational changes at the electron acceptor side and at the Mn4CaO5 core of the OEC. These include an elongation of the metal cluster, accompanied by changes in the protein environment, which could allow for binding of the second substrate water molecule between the more distant protruding Mn (referred to as the 'dangler' Mn) and the Mn3CaOx cubane in the S2 to S3 transition, as predicted by spectroscopic and computational studies. This work shows the great potential for time-resolved serial femtosecond crystallography for investigation of catalytic processes in biomolecules.
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15
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Noguchi T. Fourier transform infrared difference and time-resolved infrared detection of the electron and proton transfer dynamics in photosynthetic water oxidation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1847:35-45. [PMID: 24998309 DOI: 10.1016/j.bbabio.2014.06.009] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 06/25/2014] [Accepted: 06/26/2014] [Indexed: 01/15/2023]
Abstract
Photosynthetic water oxidation, which provides the electrons necessary for CO₂ reduction and releases O₂ and protons, is performed at the Mn₄CaO₅ cluster in photosystem II (PSII). In this review, studies that assessed the mechanism of water oxidation using infrared spectroscopy are summarized focusing on electron and proton transfer dynamics. Structural changes in proteins and water molecules between intermediates known as Si states (i=0-3) were detected using flash-induced Fourier transform infrared (FTIR) difference spectroscopy. Electron flow in PSII and proton release from substrate water were monitored using the infrared changes in ferricyanide as an exogenous electron acceptor and Mes buffer as a proton acceptor. Time-resolved infrared (TRIR) spectroscopy provided information on the dynamics of proton-coupled electron transfer during the S-state transitions. In particular, a drastic proton movement during the lag phase (~200μs) before electron transfer in the S3→S0 transition was detected directly by monitoring the infrared absorption of a polarizable proton in a hydrogen bond network. Furthermore, the proton release pathways in the PSII proteins were analyzed by FTIR difference measurements in combination with site-directed mutagenesis, isotopic substitutions, and quantum chemical calculations. Therefore, infrared spectroscopy is a powerful tool for understanding the molecular mechanism of photosynthetic water oxidation. This article is part of a Special Issue entitled: Vibrational spectroscopies and bioenergetic systems.
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Affiliation(s)
- Takumi Noguchi
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan.
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16
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Mokvist F, Sjöholm J, Mamedov F, Styring S. The Photochemistry in Photosystem II at 5 K Is Different in Visible and Far-Red Light. Biochemistry 2014; 53:4228-38. [DOI: 10.1021/bi5006392] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fredrik Mokvist
- Molecular Biomimetics, Department
of Chemistry-Ångström, Uppsala University, Ångström Laboratory, P.O. Box 523, S-751 20 Uppsala, Sweden
| | - Johannes Sjöholm
- Molecular Biomimetics, Department
of Chemistry-Ångström, Uppsala University, Ångström Laboratory, P.O. Box 523, S-751 20 Uppsala, Sweden
| | - Fikret Mamedov
- Molecular Biomimetics, Department
of Chemistry-Ångström, Uppsala University, Ångström Laboratory, P.O. Box 523, S-751 20 Uppsala, Sweden
| | - Stenbjörn Styring
- Molecular Biomimetics, Department
of Chemistry-Ångström, Uppsala University, Ångström Laboratory, P.O. Box 523, S-751 20 Uppsala, Sweden
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17
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Yang L, Zhou H, Fan T, Zhang D. Semiconductor photocatalysts for water oxidation: current status and challenges. Phys Chem Chem Phys 2014; 16:6810-26. [PMID: 24599528 DOI: 10.1039/c4cp00246f] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Artificial photosynthesis is a highly-promising strategy to convert solar energy into hydrogen energy for the relief of the global energy crisis. Water oxidation is the bottleneck for its kinetic and energetic complexity in the further enhancement of the overall efficiency of the artificial photosystem. Developing efficient and cost-effective photocatalysts for water oxidation is a growing desire, and semiconductor photocatalysts have recently attracted more attention due to their stability and simplicity. This article reviews the recent advancement of semiconductor photocatalysts with a focus on the relationship between material optimization and water oxidation efficiency. A brief introduction to artificial photosynthesis and water oxidation is given first, followed by an explanation of the basic rules and mechanisms of semiconductor particulate photocatalysts for water oxidation as theoretical references for discussions of componential, surface structure, and crystal structure modification. O2-evolving photocatalysts in Z-scheme systems are also introduced to demonstrate practical applications of water oxidation photocatalysts in artificial photosystems. The final part proposes some challenges based on the dynamics and energetics of photoholes which are fundamental to the enhancement of water oxidation efficiency, as well as on the simulation of natural water oxidation that will be a trend in future research.
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Affiliation(s)
- Lingling Yang
- State Key Lab of Metal Matrix Composites, Shanghai Jiaotong University, Shanghai 200240, P.R. China.
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18
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Pham LV, Messinger J. Electrochemically produced hydrogen peroxide affects Joliot-type oxygen-evolution measurements of photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1411-6. [PMID: 24486444 DOI: 10.1016/j.bbabio.2014.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 01/18/2014] [Accepted: 01/22/2014] [Indexed: 11/19/2022]
Abstract
The main technique employed to characterize the efficiency of water-splitting in photosynthetic preparations in terms of miss and double hit parameters and for the determination of Si (i=2,3,0) state lifetimes is the measurement of flash-induced oxygen oscillation pattern on bare platinum (Joliot-type) electrodes. We demonstrate here that this technique is not innocent. Polarization of the electrode against an Ag/AgCl electrode leads to a time-dependent formation of hydrogen peroxide by two-electron reduction of dissolved oxygen continuously supplied by the flow buffer. While the miss and double hit parameters are almost unaffected by H₂O₂, a time dependent reduction of S1 to S₋₁ occurs over a time period of 20 min. The S1 reduction can be largely prevented by adding catalase or by removing O₂ from the flow buffer with N₂. Importantly, we demonstrate that even at the shortest possible polarization times (40s in our set up) the S₂ and S₀ decays are significantly accelerated by the side reaction with H₂O₂. The removal of hydrogen peroxide leads to unperturbed S₂ state data that reveal three instead of the traditionally reported two phases of decay. In addition, even under the best conditions (catalase+N₂; 40s polarization) about 4% of S₋₁ state is observed in well dark-adapted samples, likely indicating limitations of the equal fit approach. This article is part of a special issue entitled: photosynthesis research for sustainability: keys to produce clean energy.
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Affiliation(s)
- Long Vo Pham
- Department of Chemistry, Chemistry Biology Center (KBC), Umeå University, Linnaeus väg 6, SE-901 87 Umeå, Sweden
| | - Johannes Messinger
- Department of Chemistry, Chemistry Biology Center (KBC), Umeå University, Linnaeus väg 6, SE-901 87 Umeå, Sweden.
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19
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Laisk A, Oja V. Thermal phase and excitonic connectivity in fluorescence induction. PHOTOSYNTHESIS RESEARCH 2013; 117:431-448. [PMID: 24005848 DOI: 10.1007/s11120-013-9915-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 08/19/2013] [Indexed: 05/28/2023]
Abstract
Chl fluorescence induction (FI) was recorded in sunflower leaves pre-adapted to darkness or low preferentially PSI light, or inhibited by DCMU. For analysis the FI curves were plotted against the cumulative number of excitations quenched by PSII, n q, calculated as the cumulative complementary area above the FI curve. In the +DCMU leaves n q was <1 per PSII, suggesting pre-reduction of Q A during the dark pre-exposure. A strongly sigmoidal FI curve was constructed by complementing (shifting) the recorded FI curves to n q = 1 excitation per PSII. The full FI curve in +DCMU leaves was well fitted by a model assuming PSII antennae are excitonically connected in domains of four PSII. This result, obtained by gradually reducing Q A in PSII with pre-blocked Q B (by DCMU or PQH2), differs from that obtained by gradually blocking the Q B site (by increasing DCMU or PQH2 level) in leaves during (quasi)steady-state e(-) transport (Oja and Laisk, Photosynth Res 114, 15-28, 2012). Explanations are discussed. Donor side quenching was characterized by comparison of the total n q in one and the same dark-adapted leaf, which apparently increased with increasing PFD during FI. An explanation for the donor side quenching is proposed, based on electron transfer from excited P680* to oxidized tyrosine Z (TyrZ(ox)). At high PFDs the donor side quenching at the J inflection of FI is due mainly to photochemical quenching by TyrZ(ox). This quenching remains active for subsequent photons while TyrZ remains oxidized, following charge transfer to Q A. During further induction this quenching disappears as soon as PQ and Q A become reduced, charge separation becomes impossible and TyrZ is reduced by the water oxidizing complex.
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Affiliation(s)
- Agu Laisk
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia,
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20
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Shevela D, Nöring B, Koroidov S, Shutova T, Samuelsson G, Messinger J. Efficiency of photosynthetic water oxidation at ambient and depleted levels of inorganic carbon. PHOTOSYNTHESIS RESEARCH 2013; 117:401-12. [PMID: 23828399 DOI: 10.1007/s11120-013-9875-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Accepted: 06/20/2013] [Indexed: 05/09/2023]
Abstract
Over 40 years ago, Joliot et al. (Photochem Photobiol 10:309-329, 1969) designed and employed an elegant and highly sensitive electrochemical technique capable of measuring O2 evolved by photosystem II (PSII) in response to trains of single turn-over light flashes. The measurement and analysis of flash-induced oxygen evolution patterns (FIOPs) has since proven to be a powerful method for probing the turnover efficiency of PSII. Stemler et al. (Proc Natl Acad Sci USA 71(12):4679-4683, 1974), in Govindjee's lab, were the first to study the effect of "bicarbonate" on FIOPs by adding the competitive inhibitor acetate. Here, we extend this earlier work by performing FIOPs experiments at various, strictly controlled inorganic carbon (Ci) levels without addition of any inhibitors. For this, we placed a Joliot-type bare platinum electrode inside a N2-filled glove-box (containing 10-20 ppm CO2) and reduced the Ci concentration simply by washing the samples in Ci-depleted media. FIOPs of spinach thylakoids were recorded either at 20-times reduced levels of Ci or at ambient Ci conditions (390 ppm CO2). Numerical analysis of the FIOPs within an extended Kok model reveals that under Ci-depleted conditions the miss probability is discernibly larger (by 2-3 %) than at ambient conditions, and that the addition of 5 mM HCO3 (-) to the Ci-depleted thylakoids largely restores the original miss parameter. Since a "mild" Ci-depletion procedure was employed, we discuss our data with respect to a possible function of free or weakly bound HCO3 (-) at the water-splitting side of PSII.
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Affiliation(s)
- Dmitriy Shevela
- Department of Chemistry, Chemical Biological Centre, University of Umeå, 90187, Umeå, Sweden,
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21
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Cox N, Messinger J. Reflections on substrate water and dioxygen formation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:1020-30. [PMID: 23380392 DOI: 10.1016/j.bbabio.2013.01.013] [Citation(s) in RCA: 204] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 01/23/2013] [Accepted: 01/25/2013] [Indexed: 11/30/2022]
Abstract
This brief article aims at presenting a concise summary of all experimental findings regarding substrate water-binding to the Mn4CaO5 cluster in photosystem II. Mass spectrometric and spectroscopic results are interpreted in light of recent structural information of the water oxidizing complex obtained by X-ray crystallography, spectroscopy and theoretical modeling. Within this framework current proposals for the mechanism of photosynthetic water-oxidation are evaluated. This article is part of a Special Issue entitled: Metals in Bioenergetics and Biomimetics Systems.
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Affiliation(s)
- Nicholas Cox
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, Mülheim an der Ruhr, Germany
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22
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Keough JM, Zuniga AN, Jenson DL, Barry BA. Redox control and hydrogen bonding networks: proton-coupled electron transfer reactions and tyrosine Z in the photosynthetic oxygen-evolving complex. J Phys Chem B 2013; 117:1296-307. [PMID: 23346921 DOI: 10.1021/jp3118314] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In photosynthetic oxygen evolution, redox active tyrosine Z (YZ) plays an essential role in proton-coupled electron transfer (PCET) reactions. Four sequential photooxidation reactions are necessary to produce oxygen at a Mn(4)CaO(5) cluster. The sequentially oxidized states of this oxygen-evolving cluster (OEC) are called the S(n) states, where n refers to the number of oxidizing equivalents stored. The neutral radical, YZ•, is generated and then acts as an electron transfer intermediate during each S state transition. In the X-ray structure, YZ, Tyr161 of the D1 subunit, is involved in an extensive hydrogen bonding network, which includes calcium-bound water. In electron paramagnetic resonance experiments, we measured the YZ• recombination rate, in the presence of an intact Mn(4)CaO(5) cluster. We compared the S(0) and S(2) states, which differ in Mn oxidation state, and found a significant difference in the YZ• decay rate (t(1/2) = 3.3 ± 0.3 s in S(0); t(1/2) = 2.1 ± 0.3 s in S(2)) and in the solvent isotope effect (SIE) on the reaction (1.3 ± 0.3 in S(0); 2.1 ± 0.3 in S(2)). Although the YZ site is known to be solvent accessible, the recombination rate and SIE were pH independent in both S states. To define the origin of these effects, we measured the YZ• recombination rate in the presence of ammonia, which inhibits oxygen evolution and disrupts the hydrogen bond network. We report that ammonia dramatically slowed the YZ• recombination rate in the S(2) state but had a smaller effect in the S(0) state. In contrast, ammonia had no significant effect on YD•, the stable tyrosyl radical. Therefore, the alterations in YZ• decay, observed with S state advancement, are attributed to alterations in OEC hydrogen bonding and consequent differences in the YZ midpoint potential/pK(a). These changes may be caused by activation of metal-bound water molecules, which hydrogen bond to YZ. These observations document the importance of redox control in proton-coupled electron transfer reactions.
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Affiliation(s)
- James M Keough
- School of Chemistry and Biochemistry and the Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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23
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Siegbahn PEM. Water oxidation mechanism in photosystem II, including oxidations, proton release pathways, O-O bond formation and O2 release. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1827:1003-19. [PMID: 23103385 DOI: 10.1016/j.bbabio.2012.10.006] [Citation(s) in RCA: 286] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 10/15/2012] [Accepted: 10/18/2012] [Indexed: 11/17/2022]
Abstract
The present status of DFT studies on water oxidation in photosystem II is described. It is argued that a full understanding of all steps is close. In each S-transition, the manganese that is oxidized and the proton released are strongly implicated, and structures of all intermediates have been determined. For the S2-state, recent important experimental findings support key elements of the structure and the mechanism. In this mechanism, the O-O bond is formed between an oxyl radical in the center of the cluster and an Mn-bridging μ-oxo ligand, which was suggested already in 2006. The DFT structure of the oxygen evolving complex, suggested in 2008, is very similar to the recent high-resolution X-ray structure. Some new aspects of the interaction between P680 and the OEC are suggested. This article is part of a Special Issue entitled: Metals in Bioenergetics and Biomimetics Systems.
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24
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Suzuki H, Sugiura M, Noguchi T. Determination of the Miss Probabilities of Individual S-State Transitions during Photosynthetic Water Oxidation by Monitoring Electron Flow in Photosystem II Using FTIR Spectroscopy. Biochemistry 2012; 51:6776-85. [DOI: 10.1021/bi300708a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hiroyuki Suzuki
- Division of Material Science,
Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Miwa Sugiura
- Cell-Free Science and Technology
Research Center, Ehime University, Matsuyama,
Ehime 790-8577, Japan
- PRESTO, Japan Science and Technology Agency (JST), 4-1-8, Honcho, Kawagchi,
Saitama 332-0012, 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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