1
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Cao G, Liu Y, Hu J, Qu J, Zhang Z, Xiong X, Sun W, Yang X, Li CM. Alternating 3 rd- to 2 nd-Order Charge Reaction Kinetics on Bismuth Vanadate Photoanodes with Ultrathin Bismuth Metal-Organic-Frameworks. Chemphyschem 2024; 25:e202400141. [PMID: 38462507 DOI: 10.1002/cphc.202400141] [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: 02/07/2024] [Revised: 03/09/2024] [Accepted: 03/10/2024] [Indexed: 03/12/2024]
Abstract
The most challenging obstacle for photocatalysts to efficiently harvest solar energy is the sluggish surface redox reaction (e. g., oxygen evolution reaction, OER) kinetics, which is believed to originate from interface catalysis rather than the semiconductor photophysics. In this work, we developed a light-modulated transient photocurrent (LMTPC) method for investigating surface charge accumulation and reaction on the W-doped bismuth vanadate (W : BiVO4) photoanodes during photoelectrochemical water oxidation. Under illuminating conditions, the steady photocurrent corresponds to the charge transfer rate/kinetics, while the integration of photocurrent (I~t) spikes during the dark period is regarded as the charge density under illumination. Quantitative analysis of the surface hole densities and photocurrents at 0.6 V vs. reversible hydrogen electrode results in an interesting rate-law kinetics switch: a 3rd-order charge reaction behavior appeared on W : BiVO4, but a 2nd-order charge reaction occurred on W : BiVO4 surface modified with ultrathin Bi metal-organic-framework (Bi-MOF). Consequently, the photocurrent for water oxidation on W : BiVO4/Bi-MOF displayed a 50 % increment. The reaction kinetics alternation with new interface reconstruction is proposed for new mechanism understanding and/or high-performance photocatalytic applications.
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Affiliation(s)
- Guangming Cao
- Institute of Materials Science and Devices, School of Material Science and Engineering, Suzhou University of Science and Technology, No. 99 Xuefu Rd., Suzhou, Jiangsu Province, 215009, P.R. China
- Key Laboratory of Laser Technology and Optoelectronic Functional Materials of Hainan Province, Key Laboratory of Functional Materials and Photoelectrochemistry of Haikou, College of Chemistry and Chemical Engineering, Hainan Normal University, No. 99 Longkun South Rd., Haikou, Hainan Province, 571158, P.R. China
| | - Yanjie Liu
- Institute of Materials Science and Devices, School of Material Science and Engineering, Suzhou University of Science and Technology, No. 99 Xuefu Rd., Suzhou, Jiangsu Province, 215009, P.R. China
| | - Jundie Hu
- Institute of Materials Science and Devices, School of Material Science and Engineering, Suzhou University of Science and Technology, No. 99 Xuefu Rd., Suzhou, Jiangsu Province, 215009, P.R. China
| | - Jiafu Qu
- Institute of Materials Science and Devices, School of Material Science and Engineering, Suzhou University of Science and Technology, No. 99 Xuefu Rd., Suzhou, Jiangsu Province, 215009, P.R. China
| | - Zhichao Zhang
- Institute of Materials Science and Devices, School of Material Science and Engineering, Suzhou University of Science and Technology, No. 99 Xuefu Rd., Suzhou, Jiangsu Province, 215009, P.R. China
| | - Xianqiang Xiong
- School of Pharmaceutical and Materials Engineering, Taizhou University No.1139, Shifu Blvd, Jiao Jiang, Taizhou, Zhejiang Province, 318000, P.R. China
| | - Wei Sun
- Key Laboratory of Laser Technology and Optoelectronic Functional Materials of Hainan Province, Key Laboratory of Functional Materials and Photoelectrochemistry of Haikou, College of Chemistry and Chemical Engineering, Hainan Normal University, No. 99 Longkun South Rd., Haikou, Hainan Province, 571158, P.R. China
| | - Xiaogang Yang
- Institute of Materials Science and Devices, School of Material Science and Engineering, Suzhou University of Science and Technology, No. 99 Xuefu Rd., Suzhou, Jiangsu Province, 215009, P.R. China
| | - Chang Ming Li
- Institute of Materials Science and Devices, School of Material Science and Engineering, Suzhou University of Science and Technology, No. 99 Xuefu Rd., Suzhou, Jiangsu Province, 215009, P.R. China
- Key Laboratory of Laser Technology and Optoelectronic Functional Materials of Hainan Province, Key Laboratory of Functional Materials and Photoelectrochemistry of Haikou, College of Chemistry and Chemical Engineering, Hainan Normal University, No. 99 Longkun South Rd., Haikou, Hainan Province, 571158, P.R. China
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2
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Dekmak MY, Mäusle SM, Brandhorst J, Simon PS, Dau H. Tracking the first electron transfer step at the donor side of oxygen-evolving photosystem II by time-resolved infrared spectroscopy. PHOTOSYNTHESIS RESEARCH 2023:10.1007/s11120-023-01057-3. [PMID: 37995064 DOI: 10.1007/s11120-023-01057-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/24/2023] [Indexed: 11/24/2023]
Abstract
In oxygen-evolving photosystem II (PSII), the multi-phasic electron transfer from a redox-active tyrosine residue (TyrZ) to a chlorophyll cation radical (P680+) precedes the water-oxidation chemistry of the S-state cycle of the Mn4Ca cluster. Here we investigate these early events, observable within about 10 ns to 10 ms after laser-flash excitation, by time-resolved single-frequency infrared (IR) spectroscopy in the spectral range of 1310-1890 cm-1 for oxygen-evolving PSII membrane particles from spinach. Comparing the IR difference spectra at 80 ns, 500 ns, and 10 µs allowed for the identification of quinone, P680 and TyrZ contributions. A broad electronic absorption band assignable P680+ was used to trace largely specifically the P680+ reduction kinetics. The experimental time resolution was taken into account in least-square fits of P680+ transients with a sum of four exponentials, revealing two nanosecond phases (30-46 ns and 690-1110 ns) and two microsecond phases (4.5-8.3 µs and 42 µs), which mostly exhibit a clear S-state dependence, in agreement with results obtained by other methods. Our investigation paves the road for further insight in the early events associated with TyrZ oxidation and their role in the preparing the PSII donor side for the subsequent water oxidation chemistry.
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Affiliation(s)
| | - Sarah M Mäusle
- Department of Physics, Freie Universität Berlin, Berlin, Germany.
| | | | - Philipp S Simon
- Department of Physics, Freie Universität Berlin, Berlin, Germany
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Holger Dau
- Department of Physics, Freie Universität Berlin, Berlin, Germany.
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3
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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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4
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Wilson S, Johnson MP, Ruban AV. Proton motive force in plant photosynthesis dominated by ΔpH in both low and high light. PLANT PHYSIOLOGY 2021; 187:263-275. [PMID: 34618143 PMCID: PMC8418402 DOI: 10.1093/plphys/kiab270] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/23/2021] [Indexed: 05/08/2023]
Abstract
The proton motive force (pmf) across the thylakoid membrane couples photosynthetic electron transport and ATP synthesis. In recent years, the electrochromic carotenoid and chlorophyll absorption band shift (ECS), peaking ∼515 nm, has become a widely used probe to measure pmf in leaves. However, the use of this technique to calculate the parsing of the pmf between the proton gradient (ΔpH) and electric potential (Δψ) components remains controversial. Interpretation of the ECS signal is complicated by overlapping absorption changes associated with violaxanthin de-epoxidation to zeaxanthin (ΔA505) and energy-dependent nonphotochemical quenching (qE; ΔA535). In this study, we used Arabidopsis (Arabidopsis thaliana) plants with altered xanthophyll cycle activity and photosystem II subunit S (PsbS) content to disentangle these overlapping contributions. In plants where overlap among ΔA505, ΔA535, and ECS is diminished, such as npq4 (lacking ΔA535) and npq1npq4 (also lacking ΔA505), the parsing method implies the Δψ contribution is virtually absent and pmf is solely composed of ΔpH. Conversely, in plants where ΔA535 and ECS overlap is enhanced, such as L17 (a PsbS overexpressor) and npq1 (where ΔA535 is blue-shifted to 525 nm) the parsing method implies a dominant contribution of Δψ to the total pmf. These results demonstrate the vast majority of the pmf attributed by the ECS parsing method to Δψ is caused by ΔA505 and ΔA535 overlap, confirming pmf is dominated by ΔpH following the first 60 s of continuous illumination under both low and high light conditions. Further implications of these findings for the regulation of photosynthesis are discussed.
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Affiliation(s)
- Sam Wilson
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Matthew P. Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Alexander V. Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
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5
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Yang KR, Lakshmi KV, Brudvig GW, Batista VS. Is Deprotonation of the Oxygen-Evolving Complex of Photosystem II during the S1 → S2 Transition Suppressed by Proton Quantum Delocalization? J Am Chem Soc 2021; 143:8324-8332. [DOI: 10.1021/jacs.1c00633] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Ke R. Yang
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - K. V. Lakshmi
- Department of Chemistry and Chemical Biology and The Baruch ’60 Center for Biochemical Solar Energy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Gary W. Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Victor S. Batista
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
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6
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Water-oxidizing complex in Photosystem II: Its structure and relation to manganese-oxide based catalysts. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2020.213183] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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7
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Gerland L, Friedrich D, Hopf L, Donovan EJ, Wallmann A, Erdmann N, Diehl A, Bommer M, Buzar K, Ibrahim M, Schmieder P, Dobbek H, Zouni A, Bondar AN, Dau H, Oschkinat H. pH-Dependent Protonation of Surface Carboxylate Groups in PsbO Enables Local Buffering and Triggers Structural Changes. Chembiochem 2020; 21:1597-1604. [PMID: 31930693 PMCID: PMC7318136 DOI: 10.1002/cbic.201900739] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Indexed: 11/11/2022]
Abstract
Photosystem II (PSII) catalyzes the splitting of water, releasing protons and dioxygen. Its highly conserved subunit PsbO extends from the oxygen‐evolving center (OEC) into the thylakoid lumen and stabilizes the catalytic Mn4CaO5 cluster. The high degree of conservation of accessible negatively charged surface residues in PsbO suggests additional functions, as local pH buffer or by affecting the flow of protons. For this discussion, we provide an experimental basis, through the determination of pKa values of water‐accessible aspartate and glutamate side‐chain carboxylate groups by means of NMR. Their distribution is strikingly uneven, with high pKa values around 4.9 clustered on the luminal PsbO side and values below 3.5 on the side facing PSII. pH‐dependent changes in backbone chemical shifts in the area of the lumen‐exposed loops are observed, indicating conformational changes. In conclusion, we present a site‐specific analysis of carboxylate group proton affinities in PsbO, providing a basis for further understanding of proton transport in photosynthesis.
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Affiliation(s)
- Lisa Gerland
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Department of NMR-Supported Structural Biology, Robert-Rössle-Strasse 10, 13125, Berlin, Germany.,Freie Universität Berlin, Department of Biology, Chemistry and Pharmacy, Thielallee 63, 14195, Berlin, Germany
| | - Daniel Friedrich
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Department of NMR-Supported Structural Biology, Robert-Rössle-Strasse 10, 13125, Berlin, Germany.,Freie Universität Berlin, Department of Biology, Chemistry and Pharmacy, Thielallee 63, 14195, Berlin, Germany
| | - Linus Hopf
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Department of NMR-Supported Structural Biology, Robert-Rössle-Strasse 10, 13125, Berlin, Germany.,Freie Universität Berlin, Department of Biology, Chemistry and Pharmacy, Thielallee 63, 14195, Berlin, Germany
| | - Eavan J Donovan
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Department of NMR-Supported Structural Biology, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Arndt Wallmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Department of NMR-Supported Structural Biology, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Natalja Erdmann
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Department of NMR-Supported Structural Biology, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Anne Diehl
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Department of NMR-Supported Structural Biology, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Martin Bommer
- Max-Delbrück-Centrum für Molekulare Medizin, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Krzysztof Buzar
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, 14195, Berlin, Germany
| | - Mohamed Ibrahim
- Humboldt-Universität zu Berlin, Institute of Biology, Philippstrasse 13, 10099, Berlin, Germany
| | - Peter Schmieder
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Department of NMR-Supported Structural Biology, Robert-Rössle-Strasse 10, 13125, Berlin, Germany
| | - Holger Dobbek
- Humboldt-Universität zu Berlin, Institute of Biology, Philippstrasse 13, 10099, Berlin, Germany
| | - Athina Zouni
- Humboldt-Universität zu Berlin, Institute of Biology, Philippstrasse 13, 10099, Berlin, Germany
| | - Ana-Nicoleta Bondar
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, 14195, Berlin, Germany
| | - Holger Dau
- Freie Universität Berlin, Department of Physics, Biophysics and Photosynthesis, Arnimallee 14, 14195, Berlin, Germany
| | - Hartmut Oschkinat
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Department of NMR-Supported Structural Biology, Robert-Rössle-Strasse 10, 13125, Berlin, Germany.,Freie Universität Berlin, Department of Biology, Chemistry and Pharmacy, Thielallee 63, 14195, Berlin, Germany
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8
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Selecting between two transition states by which water oxidation intermediates decay on an oxide surface. Nat Catal 2019. [DOI: 10.1038/s41929-019-0332-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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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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Davis GA, Kramer DM. Optimization of ATP Synthase c-Rings for Oxygenic Photosynthesis. FRONTIERS IN PLANT SCIENCE 2019; 10:1778. [PMID: 32082344 PMCID: PMC7003800 DOI: 10.3389/fpls.2019.01778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 12/20/2019] [Indexed: 05/10/2023]
Abstract
The conversion of sunlight into useable cellular energy occurs via the proton-coupled electron transfer reactions of photosynthesis. Light is absorbed by photosynthetic pigments and transferred to photochemical reaction centers to initiate electron and proton transfer reactions to store energy in a redox gradient and an electrochemical proton gradient (proton motive force, pmf), composed of a concentration gradient (ΔpH) and an electric field (Δψ), which drives the synthesis of ATP through the thylakoid FoF1-ATP synthase. Although ATP synthase structure and function are conserved across biological kingdoms, the number of membrane-embedded ion-binding c subunits varies between organisms, ranging from 8 to 17, theoretically altering the H+/ATP ratio for different ATP synthase complexes, with profound implications for the bioenergetic processes of cellular metabolism. Of the known c-ring stoichiometries, photosynthetic c-rings are among the largest identified stoichiometries, and it has been proposed that decreasing the c-stoichiometry could increase the energy conversion efficiency of photosynthesis. Indeed, there is strong evidence that the high H+/ATP of the chloroplast ATP synthase results in a low ATP/nicotinamide adenine dinucleotide phosphate (NADPH) ratio produced by photosynthetic linear electron flow, requiring secondary processes such as cyclic electron flow to support downstream metabolism. We hypothesize that the larger c subunit stoichiometry observed in photosynthetic ATP synthases was selected for because it allows the thylakoid to maintain pmf in a range where ATP synthesis is supported, but avoids excess Δψ and ΔpH, both of which can lead to production of reactive oxygen species and subsequent photodamage. Numerical kinetic simulations of the energetics of chloroplast photosynthetic reactions with altered c-ring size predicts the energy storage of pmf and its effects on the photochemical reaction centers strongly support this hypothesis, suggesting that, despite the low efficiency and suboptimal ATP/NADPH ratio, a high H+/ATP is favored to avoid photodamage. This has important implications for the evolution and regulation of photosynthesis as well as for synthetic biology efforts to alter photosynthetic efficiency by engineering the ATP synthase.
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Affiliation(s)
- Geoffry A. Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
| | - David M. Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
- *Correspondence: David M. Kramer,
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11
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Zaharieva I, Dau H. Energetics and Kinetics of S-State Transitions Monitored by Delayed Chlorophyll Fluorescence. FRONTIERS IN PLANT SCIENCE 2019; 10:386. [PMID: 30984228 PMCID: PMC6450259 DOI: 10.3389/fpls.2019.00386] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 03/13/2019] [Indexed: 05/21/2023]
Abstract
Understanding energetic and kinetic parameters of intermediates formed in the course of the reaction cycle (S-state cycle) of photosynthetic water oxidation is of high interest and could support the rationale designs of artificial systems for solar fuels. We use time-resolved measurements of the delayed chlorophyll fluorescence to estimate rate constants, activation energies, free energy differences, and to discriminate between the enthalpic and the entropic contributions to the decrease of the Gibbs free energy of the individual transitions. Using a joint-fit simulation approach, kinetic parameters are determined for the reaction intermediates in the S-state transitions in buffers with different pH in H2O and in D2O.
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Affiliation(s)
| | - Holger Dau
- *Correspondence: Ivelina Zaharieva, Holger Dau,
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12
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Shamsipur M, Pashabadi A. Latest advances in PSII features and mechanism of water oxidation. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.07.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Davis GA, Rutherford AW, Kramer DM. Hacking the thylakoid proton motive force for improved photosynthesis: modulating ion flux rates that control proton motive force partitioning into Δ ψ and ΔpH. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0381. [PMID: 28808100 DOI: 10.1098/rstb.2016.0381] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2017] [Indexed: 11/12/2022] Open
Abstract
There is considerable interest in improving plant productivity by altering the dynamic responses of photosynthesis in tune with natural conditions. This is exemplified by the 'energy-dependent' form of non-photochemical quenching (qE), the formation and decay of which can be considerably slower than natural light fluctuations, limiting photochemical yield. In addition, we recently reported that rapidly fluctuating light can produce field recombination-induced photodamage (FRIP), where large spikes in electric field across the thylakoid membrane (Δψ) induce photosystem II recombination reactions that produce damaging singlet oxygen (1O2). Both qE and FRIP are directly linked to the thylakoid proton motive force (pmf), and in particular, the slow kinetics of partitioning pmf into its ΔpH and Δψ components. Using a series of computational simulations, we explored the possibility of 'hacking' pmf partitioning as a target for improving photosynthesis. Under a range of illumination conditions, increasing the rate of counter-ion fluxes across the thylakoid membrane should lead to more rapid dissipation of Δψ and formation of ΔpH. This would result in increased rates for the formation and decay of qE while resulting in a more rapid decline in the amplitudes of Δψ-spikes and decreasing 1O2 production. These results suggest that ion fluxes may be a viable target for plant breeding or engineering. However, these changes also induce transient, but substantial mismatches in the ATP : NADPH output ratio as well as in the osmotic balance between the lumen and stroma, either of which may explain why evolution has not already accelerated thylakoid ion fluxes. Overall, though the model is simplified, it recapitulates many of the responses seen in vivo, while spotlighting critical aspects of the complex interactions between pmf components and photosynthetic processes. By making the programme available, we hope to enable the community of photosynthesis researchers to further explore and test specific hypotheses.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'.
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Affiliation(s)
- Geoffry A Davis
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.,Cell and Molecular Biology Graduate Program, Michigan State University, East Lansing, MI 48824, USA
| | | | - David M Kramer
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA .,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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14
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Sequential and Coupled Proton and Electron Transfer Events in the S2 → S3 Transition of Photosynthetic Water Oxidation Revealed by Time-Resolved X-ray Absorption Spectroscopy. Biochemistry 2016; 55:6996-7004. [DOI: 10.1021/acs.biochem.6b01078] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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15
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Jeon H, Jeong J, Baek K, McKie-Krisberg Z, Polle JE, Jin E. Identification of the carbonic anhydrases from the unicellular green alga Dunaliella salina strain CCAP 19/18. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.07.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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Zaharieva I, Chernev P, Berggren G, Anderlund M, Styring S, Dau H, Haumann M. Room-Temperature Energy-Sampling Kβ X-ray Emission Spectroscopy of the Mn4Ca Complex of Photosynthesis Reveals Three Manganese-Centered Oxidation Steps and Suggests a Coordination Change Prior to O2 Formation. Biochemistry 2016; 55:4197-211. [PMID: 27377097 DOI: 10.1021/acs.biochem.6b00491] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In oxygenic photosynthesis, water is oxidized and dioxygen is produced at a Mn4Ca complex bound to the proteins of photosystem II (PSII). Valence and coordination changes in its catalytic S-state cycle are of great interest. In room-temperature (in situ) experiments, time-resolved energy-sampling X-ray emission spectroscopy of the Mn Kβ1,3 line after laser-flash excitation of PSII membrane particles was applied to characterize the redox transitions in the S-state cycle. The Kβ1,3 line energies suggest a high-valence configuration of the Mn4Ca complex with Mn(III)3Mn(IV) in S0, Mn(III)2Mn(IV)2 in S1, Mn(III)Mn(IV)3 in S2, and Mn(IV)4 in S3 and, thus, manganese oxidation in each of the three accessible oxidizing transitions of the water-oxidizing complex. There are no indications of formation of a ligand radical, thus rendering partial water oxidation before reaching the S4 state unlikely. The difference spectra of both manganese Kβ1,3 emission and K-edge X-ray absorption display different shapes for Mn(III) oxidation in the S2 → S3 transition when compared to Mn(III) oxidation in the S1 → S2 transition. Comparison to spectra of manganese compounds with known structures and oxidation states and varying metal coordination environments suggests a change in the manganese ligand environment in the S2 → S3 transition, which could be oxidation of five-coordinated Mn(III) to six-coordinated Mn(IV). Conceivable options for the rearrangement of (substrate) water species and metal-ligand bonding patterns at the Mn4Ca complex in the S2 → S3 transition are discussed.
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Affiliation(s)
- Ivelina Zaharieva
- Freie Universität Berlin , Department of Physics, 14195 Berlin, Germany
| | - Petko Chernev
- Freie Universität Berlin , Department of Physics, 14195 Berlin, Germany
| | - Gustav Berggren
- Uppsala University , Department of Chemistry, Ångström Laboratory, 75120 Uppsala, Sweden
| | - Magnus Anderlund
- Uppsala University , Department of Chemistry, Ångström Laboratory, 75120 Uppsala, Sweden
| | - Stenbjörn Styring
- Uppsala University , Department of Chemistry, Ångström Laboratory, 75120 Uppsala, Sweden
| | - Holger Dau
- Freie Universität Berlin , Department of Physics, 14195 Berlin, Germany
| | - Michael Haumann
- Freie Universität Berlin , Department of Physics, 14195 Berlin, Germany
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17
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Estimation of the driving force for dioxygen formation in photosynthesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:23-33. [DOI: 10.1016/j.bbabio.2015.09.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 09/10/2015] [Accepted: 09/30/2015] [Indexed: 11/22/2022]
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18
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Benlloch R, Shevela D, Hainzl T, Grundström C, Shutova T, Messinger J, Samuelsson G, Sauer-Eriksson AE. Crystal structure and functional characterization of photosystem II-associated carbonic anhydrase CAH3 in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2015; 167:950-62. [PMID: 25617045 PMCID: PMC4348767 DOI: 10.1104/pp.114.253591] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 01/16/2015] [Indexed: 05/22/2023]
Abstract
In oxygenic photosynthesis, light energy is stored in the form of chemical energy by converting CO2 and water into carbohydrates. The light-driven oxidation of water that provides the electrons and protons for the subsequent CO2 fixation takes place in photosystem II (PSII). Recent studies show that in higher plants, HCO3 (-) increases PSII activity by acting as a mobile acceptor of the protons produced by PSII. In the green alga Chlamydomonas reinhardtii, a luminal carbonic anhydrase, CrCAH3, was suggested to improve proton removal from PSII, possibly by rapid reformation of HCO3 (-) from CO2. In this study, we investigated the interplay between PSII and CrCAH3 by membrane inlet mass spectrometry and x-ray crystallography. Membrane inlet mass spectrometry measurements showed that CrCAH3 was most active at the slightly acidic pH values prevalent in the thylakoid lumen under illumination. Two crystal structures of CrCAH3 in complex with either acetazolamide or phosphate ions were determined at 2.6- and 2.7-Å resolution, respectively. CrCAH3 is a dimer at pH 4.1 that is stabilized by swapping of the N-terminal arms, a feature not previously observed in α-type carbonic anhydrases. The structure contains a disulfide bond, and redox titration of CrCAH3 function with dithiothreitol suggested a possible redox regulation of the enzyme. The stimulating effect of CrCAH3 and CO2/HCO3 (-) on PSII activity was demonstrated by comparing the flash-induced oxygen evolution pattern of wild-type and CrCAH3-less PSII preparations. We showed that CrCAH3 has unique structural features that allow this enzyme to maximize PSII activity at low pH and CO2 concentration.
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Affiliation(s)
- Reyes Benlloch
- Department of Forest Genetics and Plant Physiology (R.B) and Department of Plant Physiology (T.S., G.S.), Umeå Plant Science Centre, and Department of Chemistry, Chemistry Biology Centre (D.S., T.H., C.G., J.M., A.E.S.-E.), Umeå University, SE-90187 Umea, Sweden
| | - Dmitriy Shevela
- Department of Forest Genetics and Plant Physiology (R.B) and Department of Plant Physiology (T.S., G.S.), Umeå Plant Science Centre, and Department of Chemistry, Chemistry Biology Centre (D.S., T.H., C.G., J.M., A.E.S.-E.), Umeå University, SE-90187 Umea, Sweden
| | - Tobias Hainzl
- Department of Forest Genetics and Plant Physiology (R.B) and Department of Plant Physiology (T.S., G.S.), Umeå Plant Science Centre, and Department of Chemistry, Chemistry Biology Centre (D.S., T.H., C.G., J.M., A.E.S.-E.), Umeå University, SE-90187 Umea, Sweden
| | - Christin Grundström
- Department of Forest Genetics and Plant Physiology (R.B) and Department of Plant Physiology (T.S., G.S.), Umeå Plant Science Centre, and Department of Chemistry, Chemistry Biology Centre (D.S., T.H., C.G., J.M., A.E.S.-E.), Umeå University, SE-90187 Umea, Sweden
| | - Tatyana Shutova
- Department of Forest Genetics and Plant Physiology (R.B) and Department of Plant Physiology (T.S., G.S.), Umeå Plant Science Centre, and Department of Chemistry, Chemistry Biology Centre (D.S., T.H., C.G., J.M., A.E.S.-E.), Umeå University, SE-90187 Umea, Sweden
| | - Johannes Messinger
- Department of Forest Genetics and Plant Physiology (R.B) and Department of Plant Physiology (T.S., G.S.), Umeå Plant Science Centre, and Department of Chemistry, Chemistry Biology Centre (D.S., T.H., C.G., J.M., A.E.S.-E.), Umeå University, SE-90187 Umea, Sweden
| | - Göran Samuelsson
- Department of Forest Genetics and Plant Physiology (R.B) and Department of Plant Physiology (T.S., G.S.), Umeå Plant Science Centre, and Department of Chemistry, Chemistry Biology Centre (D.S., T.H., C.G., J.M., A.E.S.-E.), Umeå University, SE-90187 Umea, Sweden
| | - A Elisabeth Sauer-Eriksson
- Department of Forest Genetics and Plant Physiology (R.B) and Department of Plant Physiology (T.S., G.S.), Umeå Plant Science Centre, and Department of Chemistry, Chemistry Biology Centre (D.S., T.H., C.G., J.M., A.E.S.-E.), Umeå University, SE-90187 Umea, Sweden
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19
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Klauss A, Haumann M, Dau H. Seven Steps of Alternating Electron and Proton Transfer in Photosystem II Water Oxidation Traced by Time-Resolved Photothermal Beam Deflection at Improved Sensitivity. J Phys Chem B 2014; 119:2677-89. [DOI: 10.1021/jp509069p] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- André Klauss
- Freie Universität Berlin, Institut für Experimentalphysik, 14195 Berlin, Germany
| | - Michael Haumann
- Freie Universität Berlin, Institut für Experimentalphysik, 14195 Berlin, Germany
| | - Holger Dau
- Freie Universität Berlin, Institut für Experimentalphysik, 14195 Berlin, Germany
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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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Nilo-Poyanco R, Olivares D, Orellana A, Hinrichsen P, Pinto M. Proteomic analysis of grapevine (Vitis vinifera L.) leaf changes induced by transition to autotrophy and exposure to high light irradiance. J Proteomics 2013; 91:309-30. [PMID: 23933133 DOI: 10.1016/j.jprot.2013.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 06/25/2013] [Accepted: 07/02/2013] [Indexed: 01/08/2023]
Abstract
UNLABELLED Using a proteomics approach, we evaluated the response of heterotrophic and autotrophic leaves of grapevine when exposed to high light irradiation. From a total of 572 protein spots detected on two-dimensional gels, 143 spots showed significant variation caused by changes in the trophic state. High light treatment caused variation in 90 spots, and 51 spots showed variation caused by the interaction between both factors. Regarding the trophic state of the leaf, most of the proteins detected in the heterotrophic stage decreased in abundance when the leaf reached the autotrophic stage. Major differences induced by high light were detected in autotrophic leaves. In the high-light-treated autotrophic leaves several proteins involved in the oxidative stress response were up-regulated. This pattern was not observed in the high-light-treated heterotrophic leaves. This indicates that in these types of leaves other mechanisms different to the protein antioxidant system are acting to protect young leaves against the excess of light. This also suggests that these protective mechanisms rely on other sets of proteins or non-enzymatic molecules, or that differences in protein dynamics between the heterotrophic and autotrophic stages makes the autotrophic leaves more prone to the accumulation of oxidative stress response proteins. BIOLOGICAL SIGNIFICANCE Transition from a heterotrophic to an autotrophic state is a key period during which the anatomical, physiological and molecular characteristics of a leaf are defined. In many aspects the right functioning of a leaf at its mature stage depends on the conditions under what this transition occurs. This because apart of the genetic control, environmental factors like mineral nutrition, temperature, water supply, light etc. are also important in its control. Many anatomical and physiological changes have been described in several plant species, however in grapevine molecular data regarding changes triggered by this transition or by light stress are still scarce. In this study, we identify that the transition from heterotrophic to autotrophic state in grapevine triggers major changes in the leaf proteome, which are mainly related to processes such as protein synthesis, protein folding and degradation, photosynthesis and chloroplast development. With the exception of proteins involved in carbon fixation, that increased in abundance, most of the proteins detected during the heterotrophic stage decreased in abundance when the leaf reached its autotrophic stage. This is most likely because leaves have reached their full size and from now they have to work as a carbon source for sink organs located in other parts of the plant. Despite the potential control of this transition by light, to date, no studies using a proteomics approach have been conducted to gain a broader view of the effects of short-term high light stress. Our results indicate that short-term high light exposure has a major impact on the proteome of the autotrophic leaves, and trigger a differential accumulation of several proteins involved in the oxidative stress response. Surprisingly, heterotrophic leaves do not display this pattern which can be attributed to a lower sensitivity of these leaves to high light stimulus. In fact we discovered that heterotrophic leaves are more tolerant to light stress than autotrophic leaves. This finding is of high biological significance because it helps to understand how young leaves are able to evolve to autotrophy in areas where high light intensities are predominant. This also reveals in this type of leaves the existence of alternative mechanisms to address this stressful condition. These observations provide new insights into the molecular changes occurring during transition of leaves to autotrophy particularly when this transition occurs under high light intensities. This for example occurs during the springtime when the grapevine buds burst and the young leaves are suddenly exposed to high light intensities.
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Affiliation(s)
- R Nilo-Poyanco
- FONDAP Centre for Genome Regulation, Núcleo Milenio en Biotecnología Celular Vegetal, Universidad Andrés Bello, Santiago, Chile
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22
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Bao H, Dilbeck PL, Burnap RL. Proton transport facilitating water-oxidation: the role of second sphere ligands surrounding the catalytic metal cluster. PHOTOSYNTHESIS RESEARCH 2013; 116:215-229. [PMID: 23975203 DOI: 10.1007/s11120-013-9907-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 08/03/2013] [Indexed: 06/02/2023]
Abstract
The ability of PSII to extract electrons from water, with molecular oxygen as a by-product, is a remarkable biochemical and evolutionary innovation. From an evolutionary perspective, the invention of PSII approximately 2.7 Ga led to the accelerated accumulation of biomass in the biosphere and the accumulation of oxygen in the atmosphere, a combination that allowed for the evolution of a much more complex and extensive biosphere than would otherwise have been possible. From the biochemical and enzymatic perspective, PSII is remarkable because of the thermodynamic and kinetic obstacles that needed to have been overcome to oxidize water as the ultimate photosynthetic electron donor. This article focuses on how proton release is an integral part of how these kinetic and thermodynamic obstacles have been overcome: the sequential removal of protons from the active site of H2O-oxidation facilitates the multistep oxidation of the substrate water at the Mn4CaOx, the catalytic heart of the H2O-oxidation reaction. As noted previously, the facilitated deprotonation of the Mn4CaOx cluster exerts a redox-leveling function preventing the accumulation of excess positive charge on the cluster, which might otherwise hinder the already energetically difficult oxidation of water. Using recent results, including the characteristics of site-directed mutants, the role of the second sphere of amino acid ligands and the associated network of water molecules surrounding the Mn4CaOx is discussed in relation to proton transport in other systems. In addition to the redox-leveling function, a trapping function is assigned to the proton release step occurring immediately prior to the dioxygen chemistry. This trapping appears to involve a yet-to-be clarified gating mechanism that facilitates to coordinated release of a proton from the neighborhood of the active site thereby insuring that the backward charge-recombination reaction does not out-compete the forward reaction of dioxygen chemistry during this final step of H2O-oxidation.
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Affiliation(s)
- Han Bao
- Department of Microbiology and Molecular Genetics, Oklahoma State University, 307 Life Sciences East, Stillwater, OK, 74078, USA
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23
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Oukarroum A, Goltsev V, Strasser RJ. Temperature effects on pea plants probed by simultaneous measurements of the kinetics of prompt fluorescence, delayed fluorescence and modulated 820 nm reflection. PLoS One 2013; 8:e59433. [PMID: 23527194 PMCID: PMC3602342 DOI: 10.1371/journal.pone.0059433] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 02/14/2013] [Indexed: 11/22/2022] Open
Abstract
Simultaneous in vivo measurements of prompt fluorescence (PF), delayed fluorescence (DF) and 820-nm reflection (MR) were made to probe response of pea leaves to 40 s incubation at high temperatures (25-50°C). We interpret our observation to suggest that heat treatment provokes an inhibition of electron donation by the oxygen evolving complex. DF, in a time range from several microseconds to milliseconds, has been thought to reflect recombination, in the dark, between the reduced primary electron acceptor QA(-) and the oxidized donor (P680(+)) of photosystem II (PSII). The lower electron transport rate through PSII after 45 and 50°C incubation also changed DF induction. We observed a decrease in the amplitude of the DF curve and a change in its shape and in its decay. Acceleration of P700(+) and PC(+) re-reduction was induced by 45°C treatment but after 50°C its reduction was slower, indicating inhibition of photosystem I. We suggest that simultaneous PF, MR and DF might provide useful information on assessing the degree of plant tolerance to different environmental stresses.
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24
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Kalaji HM, Goltsev V, Bosa K, Allakhverdiev SI, Strasser RJ. Experimental in vivo measurements of light emission in plants: a perspective dedicated to David Walker. PHOTOSYNTHESIS RESEARCH 2012; 114:69-96. [PMID: 23065335 DOI: 10.1007/s11120-012-9780-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 09/03/2012] [Indexed: 05/08/2023]
Abstract
This review is dedicated to David Walker (1928-2012), a pioneer in the field of photosynthesis and chlorophyll fluorescence. We begin this review by presenting the history of light emission studies, from the ancient times. Light emission from plants is of several kinds: prompt fluorescence (PF), delayed fluorescence (DF), thermoluminescence, and phosphorescence. In this article, we focus on PF and DF. Chlorophyll a fluorescence measurements have been used for more than 80 years to study photosynthesis, particularly photosystem II (PSII) since 1961. This technique has become a regular trusted probe in agricultural and biological research. Many measured and calculated parameters are good biomarkers or indicators of plant tolerance to different abiotic and biotic stressors. This would never have been possible without the rapid development of new fluorometers. To date, most of these instruments are based mainly on two different operational principles for measuring variable chlorophyll a fluorescence: (1) a PF signal produced following a pulse-amplitude-modulated excitation and (2) a PF signal emitted during a strong continuous actinic excitation. In addition to fluorometers, other instruments have been developed to measure additional signals, such as DF, originating from PSII, and light-induced absorbance changes due to the photooxidation of P700, from PSI, measured as the absorption decrease (photobleaching) at about 705 nm, or increase at 820 nm. In this review, the technical and theoretical basis of newly developed instruments, allowing for simultaneous measurement of the PF and the DF as well as other parameters is discussed. Special emphasis has been given to a description of comparative measurements on PF and DF. However, DF has been discussed in greater details, since it is much less used and less known than PF, but has a great potential to provide useful qualitative new information on the back reactions of PSII electron transfer. A review concerning the history of fluorometers is also presented.
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Affiliation(s)
- Hazem M Kalaji
- Department of Plant Physiology, Faculty of Agriculture and Biology, Warsaw University of Life Sciences SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland.
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25
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Feyziyev Y, Deák Z, Styring S, Bernát G. Electron transfer from Cyt b(559) and tyrosine-D to the S2 and S3 states of the water oxidizing complex in photosystem II at cryogenic temperatures. J Bioenerg Biomembr 2012; 45:111-20. [PMID: 23104119 DOI: 10.1007/s10863-012-9482-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 08/06/2012] [Indexed: 11/30/2022]
Abstract
The Mn(4)CaO(5) cluster of photosystem II (PSII) catalyzes the oxidation of water to molecular oxygen through the light-driven redox S-cycle. The water oxidizing complex (WOC) forms a triad with Tyrosine(Z) and P(680), which mediates electrons from water towards the acceptor side of PSII. Under certain conditions two other redox-active components, Tyrosine(D) (Y(D)) and Cytochrome b(559) (Cyt b(559)) can also interact with the S-states. In the present work we investigate the electron transfer from Cyt b(559) and Y(D) to the S(2) and S(3) states at 195 K. First, Y(D)(•) and Cyt b(559) were chemically reduced. The S(2) and S(3) states were then achieved by application of one or two laser flashes, respectively, on samples stabilized in the S(1) state. EPR signals of the WOC (the S(2)-state multiline signal, ML-S(2)), Y(D)(•) and oxidized Cyt b(559) were simultaneously detected during a prolonged dark incubation at 195 K. During 163 days of incubation a large fraction of the S(2) population decayed to S(1) in the S(2) samples by following a single exponential decay. Differently, S(3) samples showed an initial increase in the ML-S(2) intensity (due to S(3) to S(2) conversion) and a subsequent slow decay due to S(2) to S(1) conversion. In both cases, only a minor oxidation of Y(D) was observed. In contrast, the signal intensity of the oxidized Cyt b(559) showed a two-fold increase in both the S(2) and S(3) samples. The electron donation from Cyt b(559) was much more efficient to the S(2) state than to the S(3) state.
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Affiliation(s)
- Yashar Feyziyev
- Institute of Botany, 40 Patamdar Shosse, AZ-1073 Baku, Azerbaijan
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26
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Alternating electron and proton transfer steps in photosynthetic water oxidation. Proc Natl Acad Sci U S A 2012; 109:16035-40. [PMID: 22988080 DOI: 10.1073/pnas.1206266109] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Water oxidation by cyanobacteria, algae, and plants is pivotal in oxygenic photosynthesis, the process that powers life on Earth, and is the paradigm for engineering solar fuel-production systems. Each complete reaction cycle of photosynthetic water oxidation requires the removal of four electrons and four protons from the catalytic site, a manganese-calcium complex and its protein environment in photosystem II. In time-resolved photothermal beam deflection experiments, we monitored apparent volume changes of the photosystem II protein associated with charge creation by light-induced electron transfer (contraction) and charge-compensating proton relocation (expansion). Two previously invisible proton removal steps were detected, thereby filling two gaps in the basic reaction-cycle model of photosynthetic water oxidation. In the S(2) → S(3) transition of the classical S-state cycle, an intermediate is formed by deprotonation clearly before electron transfer to the oxidant (Y Z OX). The rate-determining elementary step (τ, approximately 30 µs at 20 °C) in the long-distance proton relocation toward the protein-water interface is characterized by a high activation energy (E(a) = 0.46 ± 0.05 eV) and strong H/D kinetic isotope effect (approximately 6). The characteristics of a proton transfer step during the S(0) → S(1) transition are similar (τ, approximately 100 µs; E(a) = 0.34 ± 0.08 eV; kinetic isotope effect, approximately 3); however, the proton removal from the Mn complex proceeds after electron transfer to . By discovery of the transient formation of two further intermediate states in the reaction cycle of photosynthetic water oxidation, a temporal sequence of strictly alternating removal of electrons and protons from the catalytic site is established.
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27
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Weinberg DR, Gagliardi CJ, Hull JF, Murphy CF, Kent CA, Westlake BC, Paul A, Ess DH, McCafferty DG, Meyer TJ. Proton-Coupled Electron Transfer. Chem Rev 2012; 112:4016-93. [DOI: 10.1021/cr200177j] [Citation(s) in RCA: 1125] [Impact Index Per Article: 93.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- David R. Weinberg
- Department
of Chemistry, University
of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290,
United States
- Department of Physical and Environmental
Sciences, Colorado Mesa University, 1100 North Avenue, Grand Junction,
Colorado 81501-3122, United States
| | - Christopher J. Gagliardi
- Department
of Chemistry, University
of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290,
United States
| | - Jonathan F. Hull
- Department
of Chemistry, University
of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290,
United States
| | - Christine Fecenko Murphy
- Department
of Chemistry, B219
Levine Science Research Center, Box 90354, Duke University, Durham,
North Carolina 27708-0354, United States
| | - Caleb A. Kent
- Department
of Chemistry, University
of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290,
United States
| | - Brittany C. Westlake
- The American Chemical Society,
1155 Sixteenth Street NW, Washington, District of Columbia 20036,
United States
| | - Amit Paul
- Department
of Chemistry, University
of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290,
United States
| | - Daniel H. Ess
- Department
of Chemistry, University
of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290,
United States
| | - Dewey Granville McCafferty
- Department
of Chemistry, B219
Levine Science Research Center, Box 90354, Duke University, Durham,
North Carolina 27708-0354, United States
| | - Thomas J. Meyer
- Department
of Chemistry, University
of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290,
United States
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28
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Fast structural changes (200-900ns) may prepare the photosynthetic manganese complex for oxidation by the adjacent tyrosine radical. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1196-207. [PMID: 22579714 DOI: 10.1016/j.bbabio.2012.04.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 04/25/2012] [Accepted: 04/30/2012] [Indexed: 11/20/2022]
Abstract
The Mn complex of photosystem II (PSII) cycles through 4 semi-stable states (S(0) to S(3)). Laser-flash excitation of PSII in the S(2) or S(3) state induces processes with time constants around 350ns, which have been assigned previously to energetic relaxation of the oxidized tyrosine (Y(Z)(ox)). Herein we report monitoring of these processes in the time domain of hundreds of nanoseconds by photoacoustic (or 'optoacoustic') experiments involving pressure-wave detection after excitation of PSII membrane particles by ns-laser flashes. We find that specifically for excitation of PSII in the S(2) state, nuclear rearrangements are induced which amount to a contraction of PSII by at least 30Å(3) (time constant of 350ns at 25°C; activation energy of 285+/-50meV). In the S(3) state, the 350-ns-contraction is about 5 times smaller whereas in S(0) and S(1), no volume changes are detectable in this time domain. It is proposed that the classical S(2)=>S(3) transition of the Mn complex is a multi-step process. The first step after Y(Z)(ox) formation involves a fast nuclear rearrangement of the Mn complex and its protein-water environment (~350ns), which may serve a dual role: (1) The Mn- complex entity is prepared for the subsequent proton removal and electron transfer by formation of an intermediate state of specific (but still unknown) atomic structure. (2) Formation of the structural intermediate is associated (necessarily) with energetic relaxation and thus stabilization of Y(Z)(ox) so that energy losses by charge recombination with the Q(A)(-) anion radical are minimized. The intermediate formed within about 350ns after Y(Z)(ox) formation in the S(2)-state is discussed in the context of two recent models of the S(2)=>S(3) transition of the water oxidation cycle. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: From Natural to Artificial.
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Extended protein/water H-bond networks in photosynthetic water oxidation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1177-90. [PMID: 22503827 DOI: 10.1016/j.bbabio.2012.03.031] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 03/19/2012] [Accepted: 03/28/2012] [Indexed: 11/23/2022]
Abstract
Oxidation of water molecules in the photosystem II (PSII) protein complex proceeds at the manganese-calcium complex, which is buried deeply in the lumenal part of PSII. Understanding the PSII function requires knowledge of the intricate coupling between the water-oxidation chemistry and the dynamic proton management by the PSII protein matrix. Here we assess the structural basis for long-distance proton transfer in the interior of PSII and for proton management at its surface. Using the recent high-resolution crystal structure of PSII, we investigate prominent hydrogen-bonded networks of the lumenal side of PSII. This analysis leads to the identification of clusters of polar groups and hydrogen-bonded networks consisting of amino acid residues and water molecules. We suggest that long-distance proton transfer and conformational coupling is facilitated by hydrogen-bonded networks that often involve more than one protein subunit. Proton-storing Asp/Glu dyads, such as the D1-E65/D2-E312 dyad connected to a complex water-wire network, may be particularly important for coupling protonation states to the protein conformation. Clusters of carboxylic amino acids could participate in proton management at the lumenal surface of PSII. We propose that rather than having a classical hydrophobic protein interior, the lumenal side of PSII resembles a complex polyelectrolyte with evolutionary optimized hydrogen-bonding networks. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.
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Dau H, Zaharieva I, Haumann M. Recent developments in research on water oxidation by photosystem II. Curr Opin Chem Biol 2012; 16:3-10. [DOI: 10.1016/j.cbpa.2012.02.011] [Citation(s) in RCA: 177] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 02/08/2012] [Accepted: 02/10/2012] [Indexed: 11/27/2022]
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Grundmeier A, Dau H. Structural models of the manganese complex of photosystem II and mechanistic implications. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:88-105. [PMID: 21787743 DOI: 10.1016/j.bbabio.2011.07.004] [Citation(s) in RCA: 191] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 07/06/2011] [Accepted: 07/08/2011] [Indexed: 11/29/2022]
Abstract
Photosynthetic water oxidation and O₂ formation are catalyzed by a Mn₄Ca complex bound to the proteins of photosystem II (PSII). The catalytic site, including the inorganic Mn₄CaO(n)H(x) core and its protein environment, is denoted as oxygen-evolving complex (OEC). Earlier and recent progress in the endeavor to elucidate the structure of the OEC is reviewed, with focus on recent results obtained by (i) X−ray spectroscopy (specifically by EXAFS analyses), and (ii) X-ray diffraction (XRD, protein crystallography). Very recently, an impressive resolution of 1.9Å has been achieved by XRD. Most likely however, all XRD data on the Mn₄CaO(n)H(x) core of the OEC are affected by X-ray induced modifications (radiation damage). Therefore and to address (important) details of the geometric and electronic structure of the OEC, a combined analysis of XRD and XAS data has been approached by several research groups. These efforts are reviewed and extended using an especially comprehensive approach. Taking into account XRD results on the protein environment of the inorganic core of the Mn complex, 12 alternative OEC models are considered and evaluated by quantitative comparison to (i) extended-range EXAFS data, (ii) polarized EXAFS of partially oriented PSII membrane particles, and (iii) polarized EXAFS of PSII crystals. We conclude that there is a class of OEC models that is in good agreement with both the recent crystallographic models and the XAS data. On these grounds, mechanistic implications for the O−O bond formation chemistry are discussed. This article is part of a Special Issue entitled: Photosystem II.
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Affiliation(s)
- My Hang V Huynh
- DE-1: High Explosive Science and Technology Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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