1
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Malcomson T, Rummel F, Barchenko M, O'Malley P. Hey ho, where'd the proton go? Final deprotonation of O6 within the S 3 state of photosystem II. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2024; 257:112946. [PMID: 38843709 DOI: 10.1016/j.jphotobiol.2024.112946] [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: 02/22/2024] [Revised: 04/04/2024] [Accepted: 05/25/2024] [Indexed: 07/16/2024]
Abstract
The deprotonation of O6 within the S3 state marks the final deprotonation event before the formation of oxygen‑oxygen bond interactions and eventual production and release of dioxygen. Gaining a thorough understanding of this event, from the proton acceptors involved, to the exfiltration pathways available, is key in determining the nature of the resulting oxygen species, influencing the mechanism through which the first oxygen‑oxygen bond forms. Computational analysis, using BS-DFT methodologies, showed that proton abstraction by the local Glu189 residue provides consistent evidence against this being a viable mechanistic pathway due to the lack of a stable product structure. In contrast, abstraction via W3 shows an increasingly stable oxo-oxo product state between r[O5O6] = 2.1 Å & 1.9 Å. The resulting oxo-oxo state is stabilised through donation of β electron character from O6 to Mn1 and α electron character from O6 to O5. This donation from the O6 lone pair is shown to be a key factor in stabilising the oxo-oxo state, in addition to showing the initiation of first O5-O6 bond.
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Affiliation(s)
- Thomas Malcomson
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, UK.
| | - Felix Rummel
- Department of Chemistry, School of Natural Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Maxim Barchenko
- Department of Chemistry, School of Natural Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Patrick O'Malley
- Department of Chemistry, School of Natural Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
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2
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Subramanyam R, Tomo T, Eaton-Rye JJ, Yilmaz G, Allakhverdiev SI. International conference on "Photosynthesis and Hydrogen Energy Research for Sustainability-2023": in honor of Robert Blankenship, Győző Garab, Michael Grätzel, Norman Hüner and Gunnar Öquist. PHOTOSYNTHESIS RESEARCH 2024; 161:141-150. [PMID: 38502256 DOI: 10.1007/s11120-024-01087-5] [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: 11/29/2023] [Accepted: 02/06/2024] [Indexed: 03/21/2024]
Abstract
The 11th International Photosynthesis Conference on Hydrogen Energy Research and Sustainability 2023 was organized in honor of Robert Blankenship, Győző Garab, Michael Grätzel, Norman Hüner, and Gunnar Öquist, in Istanbul, Türkiye at Bahçeşehir University Future Campus from 03 to 09 July 2023. It was jointly supported by the International Society of Photosynthesis Research (ISPR) and the International Association for Hydrogen Energy (IAHE). In this article we provide brief details of the conference, its events, keynote speakers, and the scientific contribution of scientists honored at this conference. Further, we also describe the participation of young researchers, their talks, and their awards.
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Affiliation(s)
- Rajagopal Subramanyam
- Department of Plant Science, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India
| | - Tatsuya Tomo
- Department of Physics, Graduate School of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
| | - Julian J Eaton-Rye
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin, 9054, New Zealand
| | - Girayhan Yilmaz
- Faculty of Engineering and Natural Sciences, Bahcesehir University, Istanbul, Turkey
| | - Suleyman I Allakhverdiev
- Faculty of Engineering and Natural Sciences, Bahcesehir University, Istanbul, Turkey.
- К.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya St. 35, Moscow, Russia, 127276.
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3
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Henkel A, Oberthür D. A snapshot love story: what serial crystallography has done and will do for us. Acta Crystallogr D Struct Biol 2024; 80:563-579. [PMID: 38984902 PMCID: PMC11301758 DOI: 10.1107/s2059798324005588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 06/11/2024] [Indexed: 07/11/2024] Open
Abstract
Serial crystallography, born from groundbreaking experiments at the Linac Coherent Light Source in 2009, has evolved into a pivotal technique in structural biology. Initially pioneered at X-ray free-electron laser facilities, it has now expanded to synchrotron-radiation facilities globally, with dedicated experimental stations enhancing its accessibility. This review gives an overview of current developments in serial crystallography, emphasizing recent results in time-resolved crystallography, and discussing challenges and shortcomings.
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Affiliation(s)
- Alessandra Henkel
- Center for Free-Electron Laser Science CFELDeutsches Elektronen-Synchrotron DESYNotkestr. 8522607HamburgGermany
| | - Dominik Oberthür
- Center for Free-Electron Laser Science CFELDeutsches Elektronen-Synchrotron DESYNotkestr. 8522607HamburgGermany
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4
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Capone M, Parisse G, Narzi D, Guidoni L. Unravelling Mn 4Ca cluster vibrations in the S 1, S 2 and S 3 states of the Kok-Joliot cycle of photosystem II. Phys Chem Chem Phys 2024; 26:20598-20609. [PMID: 39037338 PMCID: PMC11290063 DOI: 10.1039/d4cp01307g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 07/15/2024] [Indexed: 07/23/2024]
Abstract
Vibrational spectroscopy serves as a powerful tool for characterizing intermediate states within the Kok-Joliot cycle. In this study, we employ a QM/MM molecular dynamics framework to calculate the room temperature infrared absorption spectra of the S1, S2, and S3 states via the Fourier transform of the dipole time auto-correlation function. To better analyze the computational data and assign spectral peaks, we introduce an approach based on dipole-dipole correlation function of cluster moieties of the reaction center. Our analysis reveals variation in the infrared signature of the Mn4Ca cluster along the Kok-Joliot cycle, attributed to its increasing symmetry and rigidity resulting from the rising oxidation state of the Mn ions. Furthermore, we successfully assign the debated contributions in the frequency range around 600 cm-1. This computational methodology provides valuable insights for deciphering experimental infrared spectra and understanding the water oxidation process in both biological and artificial systems.
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Affiliation(s)
- Matteo Capone
- Università degli studi dell'Aquila, Dipartimento di Scienze Fisiche e Chimiche, L'Aquila, Italy.
| | - Gianluca Parisse
- Università degli studi dell'Aquila, Dipartimento di Scienze Fisiche e Chimiche, L'Aquila, Italy.
| | - Daniele Narzi
- Università degli studi dell'Aquila, Dipartimento di Scienze Fisiche e Chimiche, L'Aquila, Italy.
| | - Leonardo Guidoni
- Università degli studi dell'Aquila, Dipartimento di Scienze Fisiche e Chimiche, L'Aquila, Italy.
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5
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Birch-Price Z, Hardy FJ, Lister TM, Kohn AR, Green AP. Noncanonical Amino Acids in Biocatalysis. Chem Rev 2024; 124:8740-8786. [PMID: 38959423 PMCID: PMC11273360 DOI: 10.1021/acs.chemrev.4c00120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 07/05/2024]
Abstract
In recent years, powerful genetic code reprogramming methods have emerged that allow new functional components to be embedded into proteins as noncanonical amino acid (ncAA) side chains. In this review, we will illustrate how the availability of an expanded set of amino acid building blocks has opened a wealth of new opportunities in enzymology and biocatalysis research. Genetic code reprogramming has provided new insights into enzyme mechanisms by allowing introduction of new spectroscopic probes and the targeted replacement of individual atoms or functional groups. NcAAs have also been used to develop engineered biocatalysts with improved activity, selectivity, and stability, as well as enzymes with artificial regulatory elements that are responsive to external stimuli. Perhaps most ambitiously, the combination of genetic code reprogramming and laboratory evolution has given rise to new classes of enzymes that use ncAAs as key catalytic elements. With the framework for developing ncAA-containing biocatalysts now firmly established, we are optimistic that genetic code reprogramming will become a progressively more powerful tool in the armory of enzyme designers and engineers in the coming years.
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Affiliation(s)
| | | | | | | | - Anthony P. Green
- Manchester Institute of Biotechnology,
School of Chemistry, University of Manchester, Manchester M1 7DN, U.K.
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6
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Wheeler TA, Tilley TD. Metal-Metal Redox Exchange to Produce Heterometallic Manganese-Cobalt Oxo Cubanes via a "Dangler" Intermediate. J Am Chem Soc 2024; 146:20279-20290. [PMID: 38978206 PMCID: PMC11273651 DOI: 10.1021/jacs.4c05367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/10/2024]
Abstract
Pendent metals bound to heterocubanes are components of well-known active sites in enzymes that mediate difficult chemical transformations. Investigations into the specific role of these metal ions, sometimes referred to as "danglers", have been hindered by a paucity of rational synthetic routes to appropriate model structures. To generate pendent metal ions bonded to an oxo cubane through a carboxylate bridge, the cubane Co4(μ3-O)4(OAc)4(t-Bupy)4 (OAc = acetate, t-Bupy = 4-tert-butylpyridine) was exposed to various metal acetate complexes. Reaction with Cu(OAc)2 gave the structurally characterized (by X-ray diffraction) dicopper dangler Cu2Co4(μ4-O)2(μ3-O)2(OAc)6(Cl)2(t-Bupy)4. In contrast, the analogous reaction with Mn(OAc)2 produced the MnIV-containing cubane cation [MnCo3(μ3-O)4(OAc)4(t-Bupy)4]+ by way of a metal-metal exchange that gives Co(OAc)2 and [CoIII(μ-OH)(OAc)]n oligomers as byproducts. Additionally, reaction of the formally CoIV cubane complex [Co4(μ3-O)4(OAc)4(t-Bupy)4][PF6] with Mn(OAc)2 gave the corresponding Mn-containing cubane in 80% yield. A mechanistic examination of the related metal-metal exchange reaction between Co4(μ3-O)4(OBz)4(py)4 (OBz = benzoate) and [Mn(acac)2(py)2][PF6] by ultraviolet-visible (UV-vis) spectroscopy provided support for a process involving rate-determining association of the reactants and electron transfer through a μ-oxo bridge in the adduct intermediate. The rates of exchange correlate with the donor strength of the cubane pyridine and benzoate ligand substituents; more electron-donating pyridine ligands accelerate metal-metal exchange, while both electron-donating and -withdrawing benzoate ligands can accelerate exchange. These experiments suggest that the basicity of the cubane oxo ligands promotes metal-metal exchange reactivity. The redox potentials of the Mn and cubane starting materials and isotopic labeling studies suggest an inner-sphere electron-transfer mechanism in a dangler intermediate.
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Affiliation(s)
- T. Alexander Wheeler
- Department
of Chemistry, University of California,
Berkeley, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - T. Don Tilley
- Department
of Chemistry, University of California,
Berkeley, Berkeley, California 94720, United States
- Chemical
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
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7
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Kornowicz A, Pietrzak T, Korona K, Terlecki M, Justyniak I, Kubas A, Lewiński J. Fresh Impetus in the Chemistry of Calcium Peroxides. J Am Chem Soc 2024; 146:18938-18947. [PMID: 38847558 PMCID: PMC11258691 DOI: 10.1021/jacs.4c00906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 05/22/2024] [Accepted: 05/22/2024] [Indexed: 07/18/2024]
Abstract
Redox-inactive metal ions are essential in modulating the reactivity of various oxygen-containing metal complexes and metalloenzymes, including photosystem II (PSII). The heart of this unique membrane-protein complex comprises the Mn4CaO5 cluster, in which the Ca2+ ion acts as a critical cofactor in the splitting of water in PSII. However, there is still a lack of studies involving Ca-based reactive oxygen species (ROS) systems, and the exact nature of the interaction between the Ca2+ center and ROS in PSII still generates intense debate. Here, harnessing a novel Ca-TEMPO complex supported by the β-diketiminate ligand to control the activation of O2, we report the isolation and structural characterization of hitherto elusive Ca peroxides, a homometallic Ca hydroperoxide and a heterometallic Ca/K peroxide. Our studies indicate that the presence of K+ cations is a key factor controlling the outcome of the oxygenation reaction of the model Ca-TEMPO complex. Combining experimental observations with computational investigations, we also propose a mechanistic rationalization for the reaction outcomes. The designed approach demonstrates metal-TEMPO complexes as a versatile platform for O2 activation and advances the understanding of Ca/ROS systems.
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Affiliation(s)
- Arkadiusz Kornowicz
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Tomasz Pietrzak
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Krzesimir Korona
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Michał Terlecki
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Iwona Justyniak
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Adam Kubas
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Janusz Lewiński
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
- Faculty
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
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8
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Guo Y, He L, Ding Y, Kloo L, Pantazis DA, Messinger J, Sun L. Closing Kok's cycle of nature's water oxidation catalysis. Nat Commun 2024; 15:5982. [PMID: 39013902 PMCID: PMC11252165 DOI: 10.1038/s41467-024-50210-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 07/03/2024] [Indexed: 07/18/2024] Open
Abstract
The Mn4CaO5(6) cluster in photosystem II catalyzes water splitting through the Si state cycle (i = 0-4). Molecular O2 is formed and the natural catalyst is reset during the final S3 → (S4) → S0 transition. Only recently experimental breakthroughs have emerged for this transition but without explicit information on the S0-state reconstitution, thus the progression after O2 release remains elusive. In this report, our molecular dynamics simulations combined with density functional calculations suggest a likely missing link for closing the cycle, i.e., restoring the first catalytic state. Specifically, the formation of closed-cubane intermediates with all hexa-coordinate Mn is observed, which would undergo proton release, water dissociation, and ligand transfer to produce the open-cubane structure of the S0 state. Thereby, we theoretically identify the previously unknown structural isomerism in the S0 state that acts as the origin of the proposed structural flexibility prevailing in the cycle, which may be functionally important for nature's water oxidation catalysis.
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Affiliation(s)
- Yu Guo
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, China
| | - Lanlan He
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, China
| | - Yunxuan Ding
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, China
| | - Lars Kloo
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-10044, Stockholm, Sweden
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
| | - Johannes Messinger
- Department of Plant Physiology, Umeå University, Linnaeus väg 6 (KBC huset), SE-90187, Umeå, Sweden
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University, SE-75120, Uppsala, Sweden
| | - Licheng Sun
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China.
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, China.
- Division of Solar Energy Conversion and Catalysis at Westlake University, Zhejiang Baima Lake Laboratory Co., Ltd., Hangzhou, 310000, Zhejiang, China.
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9
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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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10
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Konold PE, Monrroy L, Bellisario A, Filipe D, Adams P, Alvarez R, Bean R, Bielecki J, Bódizs S, Ducrocq G, Grubmueller H, Kirian RA, Kloos M, Koliyadu JCP, Koua FHM, Larkiala T, Letrun R, Lindsten F, Maihöfer M, Martin AV, Mészáros P, Mutisya J, Nimmrich A, Okamoto K, Round A, Sato T, Valerio J, Westphal D, Wollter A, Yenupuri TV, You T, Maia F, Westenhoff S. Microsecond time-resolved X-ray scattering by utilizing MHz repetition rate at second-generation XFELs. Nat Methods 2024:10.1038/s41592-024-02344-0. [PMID: 38969722 DOI: 10.1038/s41592-024-02344-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 06/10/2024] [Indexed: 07/07/2024]
Abstract
Detecting microsecond structural perturbations in biomolecules has wide relevance in biology, chemistry and medicine. Here we show how MHz repetition rates at X-ray free-electron lasers can be used to produce microsecond time-series of protein scattering with exceptionally low noise levels of 0.001%. We demonstrate the approach by examining Jɑ helix unfolding of a light-oxygen-voltage photosensory domain. This time-resolved acquisition strategy is easy to implement and widely applicable for direct observation of structural dynamics of many biochemical processes.
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Affiliation(s)
- Patrick E Konold
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Leonardo Monrroy
- Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden
| | - Alfredo Bellisario
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Diogo Filipe
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Patrick Adams
- School of Science, STEM College, RMIT University, Melbourne, Victoria, Australia
| | - Roberto Alvarez
- Department of Physics, Arizona State University, Tempe, AZ, USA
| | | | | | - Szabolcs Bódizs
- Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Gabriel Ducrocq
- Department of Computer and Information Science (IDA), Linköping University, Linköping, Sweden
- The Division of Statistics and Machine Learning (STIMA), Linköping University, Linköping, Sweden
| | - Helmut Grubmueller
- Department of Computer and Information Science (IDA), Linköping University, Linköping, Sweden
| | | | - Marco Kloos
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Jayanath C P Koliyadu
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | | | - Taru Larkiala
- Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | | | - Fredrik Lindsten
- Department of Computer and Information Science (IDA), Linköping University, Linköping, Sweden
- The Division of Statistics and Machine Learning (STIMA), Linköping University, Linköping, Sweden
| | - Michael Maihöfer
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Andrew V Martin
- School of Science, STEM College, RMIT University, Melbourne, Victoria, Australia
| | - Petra Mészáros
- Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden
| | - Jennifer Mutisya
- Department of Chemistry - BMC, Uppsala University, Uppsala, Sweden
| | - Amke Nimmrich
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Kenta Okamoto
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | | | | | | | - Daniel Westphal
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - August Wollter
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Tej Varma Yenupuri
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Tong You
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Filipe Maia
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
| | - Sebastian Westenhoff
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
- Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
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11
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Flesher DA, Liu J, Wang J, Gisriel CJ, Yang KR, Batista VS, Debus RJ, Brudvig GW. Mutation-induced shift of the photosystem II active site reveals insight into conserved water channels. J Biol Chem 2024; 300:107475. [PMID: 38879008 PMCID: PMC11294709 DOI: 10.1016/j.jbc.2024.107475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 06/02/2024] [Accepted: 06/09/2024] [Indexed: 07/11/2024] Open
Abstract
Photosystem II (PSII) is the water-plastoquinone photo-oxidoreductase central to oxygenic photosynthesis. PSII has been extensively studied for its ability to catalyze light-driven water oxidation at a Mn4CaO5 cluster called the oxygen-evolving complex (OEC). Despite these efforts, the complete reaction mechanism for water oxidation by PSII is still heavily debated. Previous mutagenesis studies have investigated the roles of conserved amino acids, but these studies have lacked a direct structural basis that would allow for a more meaningful interpretation. Here, we report a 2.14-Å resolution cryo-EM structure of a PSII complex containing the substitution Asp170Glu on the D1 subunit. This mutation directly perturbs a bridging carboxylate ligand of the OEC, which alters the spectroscopic properties of the OEC without fully abolishing water oxidation. The structure reveals that the mutation shifts the position of the OEC within the active site without markedly distorting the Mn4CaO5 cluster metal-metal geometry, instead shifting the OEC as a rigid body. This shift disturbs the hydrogen-bonding network of structured waters near the OEC, causing disorder in the conserved water channels. This mutation-induced disorder appears consistent with previous FTIR spectroscopic data. We further show using quantum mechanics/molecular mechanics methods that the mutation-induced structural changes can affect the magnetic properties of the OEC by altering the axes of the Jahn-Teller distortion of the Mn(III) ion coordinated to D1-170. These results offer new perspectives on the conserved water channels, the rigid body property of the OEC, and the role of D1-Asp170 in the enzymatic water oxidation mechanism.
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Affiliation(s)
- David A Flesher
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Jinchan Liu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | | | - Ke R Yang
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
| | - Richard J Debus
- Department of Biochemistry, University of California, Riverside, California, USA.
| | - Gary W Brudvig
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA; Department of Chemistry, Yale University, New Haven, Connecticut, USA.
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12
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Vallejos A, Katona G, Neutze R. Appraising protein conformational changes by resampling time-resolved serial x-ray crystallography data. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:044302. [PMID: 39056073 PMCID: PMC11272219 DOI: 10.1063/4.0000258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Accepted: 06/28/2024] [Indexed: 07/28/2024]
Abstract
With the development of serial crystallography at both x-ray free electron laser and synchrotron radiation sources, time-resolved x-ray crystallography is increasingly being applied to study conformational changes in macromolecules. A successful time-resolved serial crystallography study requires the growth of microcrystals, a mechanism for synchronized and homogeneous excitation of the reaction of interest within microcrystals, and tools for structural interpretation. Here, we utilize time-resolved serial femtosecond crystallography data collected from microcrystals of bacteriorhodopsin to compare results from partial occupancy structural refinement and refinement against extrapolated data. We illustrate the domain wherein the amplitude of refined conformational changes is inversely proportional to the activated state occupancy. We illustrate how resampling strategies allow coordinate uncertainty to be estimated and demonstrate that these two approaches to structural refinement agree within coordinate errors. We illustrate how singular value decomposition of a set of difference Fourier electron density maps calculated from resampled data can minimize phase bias in these maps, and we quantify residual densities for transient water molecules by analyzing difference Fourier and Polder omit maps from resampled data. We suggest that these tools may assist others in judging the confidence with which observed electron density differences may be interpreted as functionally important conformational changes.
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Affiliation(s)
- Adams Vallejos
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Gergely Katona
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Richard Neutze
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
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13
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Yano J, Kern J, Yachandra VK. Structure Function Studies of Photosystem II Using X-Ray Free Electron Lasers. Annu Rev Biophys 2024; 53:343-365. [PMID: 39013027 DOI: 10.1146/annurev-biophys-071723-102519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
The structure and mechanism of the water-oxidation chemistry that occurs in photosystem II have been subjects of great interest. The advent of X-ray free electron lasers allowed the determination of structures of the stable intermediate states and of steps in the transitions between these intermediate states, bringing a new perspective to this field. The room-temperature structures collected as the photosynthetic water oxidation reaction proceeds in real time have provided important novel insights into the structural changes and the mechanism of the water oxidation reaction. The time-resolved measurements have also given us a view of how this reaction-which involves multielectron, multiproton processes-is facilitated by the interaction of the ligands and the protein residues in the oxygen-evolving complex. These structures have also provided a picture of the dynamics occurring in the channels within photosystem II that are involved in the transport of the substrate water to the catalytic center and protons to the bulk.
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Affiliation(s)
- Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA; , ,
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA; , ,
| | - Vittal K Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA; , ,
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14
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Hussein R, Graça A, Forsman J, Aydin AO, Hall M, Gaetcke J, Chernev P, Wendler P, Dobbek H, Messinger J, Zouni A, Schröder WP. Cryo-electron microscopy reveals hydrogen positions and water networks in photosystem II. Science 2024; 384:1349-1355. [PMID: 38900892 DOI: 10.1126/science.adn6541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 05/16/2024] [Indexed: 06/22/2024]
Abstract
Photosystem II starts the photosynthetic electron transport chain that converts solar energy into chemical energy and thus sustains life on Earth. It catalyzes two chemical reactions: water oxidation to molecular oxygen and plastoquinone reduction. Coupling of electron and proton transfer is crucial for efficiency; however, the molecular basis of these processes remains speculative owing to uncertain water binding sites and the lack of experimentally determined hydrogen positions. We thus collected high-resolution cryo-electron microscopy data of fully hydrated photosystem II from the thermophilic cyanobacterium Thermosynechococcus vestitus to a final resolution of 1.71 angstroms. The structure reveals several previously undetected partially occupied water binding sites and more than half of the hydrogen and proton positions. This clarifies the pathways of substrate water binding and plastoquinone B protonation.
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Affiliation(s)
- Rana Hussein
- Humboldt-Universität zu Berlin, Department of Biology, D 10099 Berlin, Germany
| | - André Graça
- Department of Chemistry, Umeå University, SE 90187 Umeå, Sweden
- Molecular Biomimetics, Department of Chemistry- Ångström Laboratory, Uppsala University, SE 75120 Uppsala, Sweden
| | - Jack Forsman
- Department of Chemistry, Umeå University, SE 90187 Umeå, Sweden
| | - A Orkun Aydin
- Molecular Biomimetics, Department of Chemistry- Ångström Laboratory, Uppsala University, SE 75120 Uppsala, Sweden
| | - Michael Hall
- Department of Chemistry, Umeå University, SE 90187 Umeå, Sweden
| | - Julia Gaetcke
- Humboldt-Universität zu Berlin, Department of Biology, D 10099 Berlin, Germany
| | - Petko Chernev
- Molecular Biomimetics, Department of Chemistry- Ångström Laboratory, Uppsala University, SE 75120 Uppsala, Sweden
| | - Petra Wendler
- Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, Karl-Liebknecht Strasse 24-25, D 14476, Potsdam-Golm, Germany
| | - Holger Dobbek
- Humboldt-Universität zu Berlin, Department of Biology, D 10099 Berlin, Germany
| | - Johannes Messinger
- Molecular Biomimetics, Department of Chemistry- Ångström Laboratory, Uppsala University, SE 75120 Uppsala, Sweden
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Sweden
| | - Athina Zouni
- Humboldt-Universität zu Berlin, Department of Biology, D 10099 Berlin, Germany
| | - Wolfgang P Schröder
- Department of Chemistry, Umeå University, SE 90187 Umeå, Sweden
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Sweden
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15
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Yang S, Liu X, Li S, Yuan W, Yang L, Wang T, Zheng H, Cao R, Zhang W. The mechanism of water oxidation using transition metal-based heterogeneous electrocatalysts. Chem Soc Rev 2024; 53:5593-5625. [PMID: 38646825 DOI: 10.1039/d3cs01031g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
The water oxidation reaction, a crucial process for solar energy conversion, has garnered significant research attention. Achieving efficient energy conversion requires the development of cost-effective and durable water oxidation catalysts. To design effective catalysts, it is essential to have a fundamental understanding of the reaction mechanisms. This review presents a comprehensive overview of recent advancements in the understanding of the mechanisms of water oxidation using transition metal-based heterogeneous electrocatalysts, including Mn, Fe, Co, Ni, and Cu-based catalysts. It highlights the catalytic mechanisms of different transition metals and emphasizes the importance of monitoring of key intermediates to explore the reaction pathway. In addition, advanced techniques for physical characterization of water oxidation intermediates are also introduced, for the purpose of providing information for establishing reliable methodologies in water oxidation research. The study of transition metal-based water oxidation electrocatalysts is instrumental in providing novel insights into understanding both natural and artificial energy conversion processes.
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Affiliation(s)
- Shujiao Yang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
| | - Xiaohan Liu
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
| | - Sisi Li
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
| | - Wenjie Yuan
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
| | - Luna Yang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
| | - Ting Wang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
| | - Haoquan Zheng
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
| | - Rui Cao
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
| | - Wei Zhang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, P. R. China.
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16
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Chen Y, Su Y, Han J, Chen C, Fan H, Zhang C. Synthetic Mn 3Ce 2O 5-Cluster Mimicking the Oxygen-Evolving Center in Photosynthesis. CHEMSUSCHEM 2024:e202401031. [PMID: 38829180 DOI: 10.1002/cssc.202401031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Accepted: 05/28/2024] [Indexed: 06/05/2024]
Abstract
The photosynthetic oxygen-evolving center (OEC) is a unique Mn4CaO5-cluster that catalyses water splitting into electrons, protons, and dioxygen. Precisely structural and functional mimicking of the OEC is a long-standing challenge and pressingly needed for understanding the structure-function relationship and catalytic mechanism of O-O bond formation. Herein we report two simple and robust artificial Mn3Ce2O5-complexes that display a remarkable structural similarity to the OEC in regarding of the ten-atom core (five metal ions and five oxygen bridges) and the alkyl carboxylate peripheral ligands. This Mn3Ce2O5-cluster can catalyse the water-splitting reaction on the surface of ITO electrode. These results clearly show that cerium can structurally and functionally replace both calcium and manganese in the cluster. Mass spectroscopic measurements demonstrate that the oxide bridges in the cluster are exchangeable and can be rapidly replaced by the isotopic oxygen of H2 18O in acetonitrile solution, which supports that the oxide bridge(s) may serve as the active site for the formation of O-O bond during the water-splitting reaction. These results would contribute to our understanding of the structure-reactivity relationship of both natural and artificial clusters and shed new light on the development of efficient water-splitting catalysts in artificial photosynthesis.
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Affiliation(s)
- Yang Chen
- Beijing National Laboratory for Molecular Sciences and Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yao Su
- Beijing National Laboratory for Molecular Sciences and Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Juanjuan Han
- Center for Physicochemical Analysis and Measurement, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Changhui Chen
- Beijing National Laboratory for Molecular Sciences and Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Hongjun Fan
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Chunxi Zhang
- Beijing National Laboratory for Molecular Sciences and Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
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17
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Bjelčić M, Aurelius O, Nan J, Neutze R, Ursby T. Room-temperature serial synchrotron crystallography structure of Spinacia oleracea RuBisCO. Acta Crystallogr F Struct Biol Commun 2024; 80:117-124. [PMID: 38809540 PMCID: PMC11189101 DOI: 10.1107/s2053230x24004643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 05/18/2024] [Indexed: 05/30/2024] Open
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is the enzyme responsible for the first step of carbon dioxide (CO2) fixation in plants, which proceeds via the carboxylation of ribulose 1,5-biphosphate. Because of the enormous importance of this reaction in agriculture and the environment, there is considerable interest in the mechanism of fixation of CO2 by RuBisCO. Here, a serial synchrotron crystallography structure of spinach RuBisCO is reported at 2.3 Å resolution. This structure is consistent with earlier single-crystal X-ray structures of this enzyme and the results are a good starting point for a further push towards time-resolved serial synchrotron crystallography in order to better understand the mechanism of the reaction.
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Affiliation(s)
- Monika Bjelčić
- MAX IV Laboratory, Lund UniversityPO Box 118221 00LundSweden
| | - Oskar Aurelius
- MAX IV Laboratory, Lund UniversityPO Box 118221 00LundSweden
| | - Jie Nan
- MAX IV Laboratory, Lund UniversityPO Box 118221 00LundSweden
| | - Richard Neutze
- Department of Chemistry and Molecular BiologyUniversity of GothenburgMedicinaregatan 9C413 90GothenburgSweden
| | - Thomas Ursby
- MAX IV Laboratory, Lund UniversityPO Box 118221 00LundSweden
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18
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Arshad F, Eaton-Rye JJ. Indirect interactions involving the PsbM or PsbT subunits and the PsbO, PsbU and PsbV proteins stabilize assembly and activity of Photosystem II in Synechocystis sp. PCC 6803. PHOTOSYNTHESIS RESEARCH 2024; 160:61-75. [PMID: 38488942 PMCID: PMC11108944 DOI: 10.1007/s11120-024-01091-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 03/05/2024] [Indexed: 03/17/2024]
Abstract
The low-molecular-weight PsbM and PsbT proteins of Photosystem II (PS II) are both located at the monomer-monomer interface of the mature PS II dimer. Since the extrinsic proteins are associated with the final step of assembly of an active PS II monomer and, in the case of PsbO, are known to impact the stability of the PS II dimer, we have investigated the potential cooperativity between the PsbM and PsbT subunits and the PsbO, PsbU and PsbV extrinsic proteins. Blue-native polyacrylamide electrophoresis and western blotting detected stable PS II monomers in the ∆PsbM:∆PsbO and ∆PsbT:∆PsbO mutants that retained sufficient oxygen-evolving activity to support reduced photoautotrophic growth. In contrast, the ∆PsbM:∆PsbU and ∆PsbT:∆PsbU mutants assembled dimeric PS II at levels comparable to wild type and supported photoautotrophic growth at rates similar to those obtained with the corresponding ∆PsbM and ∆PsbT cells. Removal of PsbV was more detrimental than removal of PsbO. Only limited levels of dimeric PS II were observed in the ∆PsbM:∆PsbV mutant and the overall reduced level of assembled PS II in this mutant resulted in diminished rates of photoautotrophic growth and PS II activity below those obtained in the ∆PsbM:∆PsbO and ∆PsbT:∆PsbO strains. In addition, the ∆PsbT:∆PsbV mutant did not assemble active PS II centers although inactive monomers could be detected. The inability of the ∆PsbT:∆PsbV mutant to grow photoautotrophically, or to evolve oxygen, suggested a stable oxygen-evolving complex could not assemble in this mutant.
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Affiliation(s)
- Faiza Arshad
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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19
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Juda CE, Handford RC, Bartholomew AK, Powers TM, Gu NX, Meyer E, Roth N, Chen YS, Zheng SL, Betley TA. Cluster dynamics of heterometallic trinuclear clusters during ligand substitution, redox chemistry, and group transfer processes. Chem Sci 2024; 15:8242-8248. [PMID: 38817579 PMCID: PMC11134326 DOI: 10.1039/d3sc03606e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 02/04/2024] [Indexed: 06/01/2024] Open
Abstract
Stepwise metalation of the hexadentate ligand tbsLH6 (tbsLH6 = 1,3,5-C6H9(NHC6H4-o-NHSiMe2tBu)3) affords bimetallic trinuclear clusters (tbsL)Fe2Zn(thf) and (tbsL)Fe2Zn(py). Reactivity studies were pursued to understand metal atom lability as the clusters undergo ligand substitution, redox chemistry, and group transfer processes. Chloride addition to (tbsL)Fe2Zn(thf) resulted in a mixture of species including both all-zinc and all-iron products. Addition of ArN3 (Ar = Ph, 3,5-(CF3)2C6H3) to (tbsL)Fe2Zn(py) yielded a mixture of two trinuclear products: (tbsL)Fe3(μ3-NAr) and (tbsL)Fe2Zn(μ3-NAr)(py). The two imido species were separated via crystallization, and outer sphere reduction of (tbsL)Fe2Zn(μ3-NAr)(py) resulted in the formation of a single product, [2,2,2-crypt(K)][(tbsL)Fe2Zn(μ3-NAr)]. These results provide insight into the relationship between heterometallic cluster structure and substitutional lability and could help inform both future catalyst design and our understanding of metal atom lability in bioinorganic systems.
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Affiliation(s)
- Cristin E Juda
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Rex C Handford
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | | | - Tamara M Powers
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Nina X Gu
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Elisabeth Meyer
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Nikolaj Roth
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Yu-Sheng Chen
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Shao-Liang Zheng
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
| | - Theodore A Betley
- Department of Chemistry and Chemical Biology, Harvard University Cambridge MA 02139 USA
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20
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Li Y, Sun B, Liu C, Zhao Z, Ning H, Zhang P, Li F, Sun L, Li F. Promoting Water Oxidation by Proton Acceptable Groups Surrounding Catalyst on Electrode Surface. CHEMSUSCHEM 2024:e202400735. [PMID: 38771427 DOI: 10.1002/cssc.202400735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Revised: 05/10/2024] [Accepted: 05/21/2024] [Indexed: 05/22/2024]
Abstract
Large-scale hydrogen production through water splitting represents an optimal approach for storing sustainable but intermittent energy sources. However, water oxidation, a complex and sluggish reaction, poses a significant bottleneck for water splitting efficiency. The impact of outer chemical environments on the reaction kinetics of water oxidation catalytic centers remains unexplored. Herein, chemical environment impacts were integrated by featuring methylpyridinium cation group (Py+) around the classic Ru(bpy)(tpy) (bpy=2,2'-bipyridine, tpy=2,2' : 6',2''-terpyridine) water oxidation catalyst on the electrode surface via electrochemical co-polymerization. The presence of Py+ groups could significantly enhance the turnover frequencies of Ru(bpy)(tpy), surpassing the performance of typical proton acceptors such as pyridine and benzoic acid anchored around the catalyst. Mechanistic investigations reveal that the flexible internal proton acceptor anions induced by Py+ around Ru(bpy)(tpy) are more effective than conventionally anchored proton acceptors, which promoted the rate-determining proton transfer process and enhanced the rate of water nucleophilic attack during O-O bond formation. This study may provide a novel perspective on achieving efficient water oxidation systems by integrating cations into the outer chemical environments of catalytic centers.
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Affiliation(s)
- Yingzheng Li
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, 116024, Dalian, Liaoning, China
| | - Bin Sun
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, 116024, Dalian, Liaoning, China
| | - Chang Liu
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, 116024, Dalian, Liaoning, China
| | - Ziqi Zhao
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, 116024, Dalian, Liaoning, China
| | - Hongxia Ning
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, 116024, Dalian, Liaoning, China
| | - Peili Zhang
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, 116024, Dalian, Liaoning, China
| | - Fei Li
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, 116024, Dalian, Liaoning, China
| | - Licheng Sun
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, 116024, Dalian, Liaoning, China
- Center of Artificial Photosynthesis for Solar Fuels, School of Science, Westlake University, 310024, Hangzhou, Zhejiang, China
| | - Fusheng Li
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, 116024, Dalian, Liaoning, China
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21
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Saito K, Chen Y, Ishikita H. Exploring the Deprotonation Process during Incorporation of a Ligand Water Molecule at the Dangling Mn Site in Photosystem II. J Phys Chem B 2024; 128:4728-4734. [PMID: 38693711 PMCID: PMC11104351 DOI: 10.1021/acs.jpcb.4c01997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 04/18/2024] [Accepted: 04/22/2024] [Indexed: 05/03/2024]
Abstract
The Mn4CaO5 cluster, featuring four ligand water molecules (W1 to W4), serves as the water-splitting site in photosystem II (PSII). X-ray free electron laser (XFEL) structures exhibit an additional oxygen site (O6) adjacent to the O5 site in the fourth lowest oxidation state, S3, forming Mn4CaO6. Here, we investigate the mechanism of the second water ligand molecule at the dangling Mn (W2) as a potential incorporating species, using a quantum mechanical/molecular mechanical (QM/MM) approach. Previous QM/MM calculations demonstrated that W1 releases two protons through a low-barrier H-bond toward D1-Asp61 and subsequently releases an electron during the S2 to S3 transition, resulting in O•- at W1 and protonated D1-Asp61. During the process of Mn4CaO6 formation, O•-, rather than H2O or OH-, best reproduced the O5···O6 distance. Although the catalytic cluster with O•- at O6 is more stable than that with O•- at W1 in S3, it does not occur spontaneously due to the significantly uphill deprotonation process. Assuming O•- at W2 incorporates into the O6 site, an exergonic conversion from Mn1(III)Mn2(IV)Mn3(IV)Mn4(IV) (equivalent to the open-cubane S2 valence state) to Mn1(IV)Mn2(IV)Mn3(IV)Mn4(III) (equivalent to the closed-cubane S2 valence state) occurs. These findings provide energetic insights into the deprotonation and structural conversion events required for the Mn4CaO6 formation.
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Affiliation(s)
- Keisuke Saito
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Yang Chen
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Hiroshi Ishikita
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
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22
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Chen LX, Yano J. Deciphering Photoinduced Catalytic Reaction Mechanisms in Natural and Artificial Photosynthetic Systems on Multiple Temporal and Spatial Scales Using X-ray Probes. Chem Rev 2024; 124:5421-5469. [PMID: 38663009 DOI: 10.1021/acs.chemrev.3c00560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2024]
Abstract
Utilization of renewable energies for catalytically generating value-added chemicals is highly desirable in this era of rising energy demands and climate change impacts. Artificial photosynthetic systems or photocatalysts utilize light to convert abundant CO2, H2O, and O2 to fuels, such as carbohydrates and hydrogen, thus converting light energy to storable chemical resources. The emergence of intense X-ray pulses from synchrotrons, ultrafast X-ray pulses from X-ray free electron lasers, and table-top laser-driven sources over the past decades opens new frontiers in deciphering photoinduced catalytic reaction mechanisms on the multiple temporal and spatial scales. Operando X-ray spectroscopic methods offer a new set of electronic transitions in probing the oxidation states, coordinating geometry, and spin states of the metal catalytic center and photosensitizers with unprecedented energy and time resolution. Operando X-ray scattering methods enable previously elusive reaction steps to be characterized on different length scales and time scales. The methodological progress and their application examples collected in this review will offer a glimpse into the accomplishments and current state in deciphering reaction mechanisms for both natural and synthetic systems. Looking forward, there are still many challenges and opportunities at the frontier of catalytic research that will require further advancement of the characterization techniques.
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Affiliation(s)
- Lin X Chen
- Chemical Science and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Junko Yano
- Molecular Biophysics & Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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23
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Lee Y, Oang KY, Kim D, Ihee H. A comparative review of time-resolved x-ray and electron scattering to probe structural dynamics. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:031301. [PMID: 38706888 PMCID: PMC11065455 DOI: 10.1063/4.0000249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/10/2024] [Indexed: 05/07/2024]
Abstract
The structure of molecules, particularly the dynamic changes in structure, plays an essential role in understanding physical and chemical phenomena. Time-resolved (TR) scattering techniques serve as crucial experimental tools for studying structural dynamics, offering direct sensitivity to molecular structures through scattering signals. Over the past decade, the advent of x-ray free-electron lasers (XFELs) and mega-electron-volt ultrafast electron diffraction (MeV-UED) facilities has ushered TR scattering experiments into a new era, garnering significant attention. In this review, we delve into the basic principles of TR scattering experiments, especially focusing on those that employ x-rays and electrons. We highlight the variations in experimental conditions when employing x-rays vs electrons and discuss their complementarity. Additionally, cutting-edge XFELs and MeV-UED facilities for TR x-ray and electron scattering experiments and the experiments performed at those facilities are reviewed. As new facilities are constructed and existing ones undergo upgrades, the landscape for TR x-ray and electron scattering experiments is poised for further expansion. Through this review, we aim to facilitate the effective utilization of these emerging opportunities, assisting researchers in delving deeper into the intricate dynamics of molecular structures.
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Affiliation(s)
| | - Key Young Oang
- Radiation Center for Ultrafast Science, Korea Atomic Energy Research Institute (KAERI), Daejeon 34057, South Korea
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24
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Stewart J, Zayka P, Courter C, Cuk T. Formation of the oxyl's potential energy surface by the spectral kinetics of a vibrational mode. J Chem Phys 2024; 160:164202. [PMID: 38682740 DOI: 10.1063/5.0202441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Accepted: 04/07/2024] [Indexed: 05/01/2024] Open
Abstract
One of the most reactive intermediates for oxidative reactions is the oxyl radical, an electron-deficient oxygen atom. The discovery of a new vibration upon photoexcitation of the oxygen evolution catalysis detected the oxyl radical at the SrTiO3 surface. The vibration was assigned to a motion of the sub-surface oxygen underneath the titanium oxyl (Ti-O●-) created upon hole transfer to (or electron extraction from) a hydroxylated surface site. Evidence for such an interfacial mode is derived from its spectral shape, which exhibited a Fano resonance-a coupling of a sharp normal mode to continuum excitations. Here, this Fano resonance is utilized to derive precise formation kinetics of the oxyl radical and its associated potential energy surface (PES). From the Fano lineshape, the formation kinetics are obtained from the anti-resonance (the kinetics of the coupling factor), the resonance (the kinetics of the coupled continuum excitations), and the frequency integrated spectrum (the kinetics of the normal mode's cross-section). All three perspectives yield logistic function growth with a half-rise of 2.3 ± 0.3 ps and a time constant of 0.48 ± 0.09 ps. A non-equilibrium transient associated with photoexcitation is separated from the rise of the equilibrated PES. The logistic function characterizes the oxyl coverage at the very initial stages (t ∼ 0) to have an exponential growth rate that quickly decreases toward zero as a limiting coverage is reached. Such time-dependent reaction kinetics identify a dynamic activation barrier associated with the formation of a PES and quantify it for oxyl radical coverage.
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Affiliation(s)
- James Stewart
- Department of Chemistry, University of Colorado, Boulder, Colorado 80303, USA
| | - Paul Zayka
- Department of Chemistry, University of Colorado, Boulder, Colorado 80303, USA
| | - Christen Courter
- Department of Chemistry, University of Colorado, Boulder, Colorado 80303, USA
| | - Tanja Cuk
- Department of Chemistry, University of Colorado, Boulder, Colorado 80303, USA
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado, Boulder, Colorado 80303, USA
- Materials Science and Engineering Program (MSE), University of Colorado, Boulder, Colorado 80303, USA
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25
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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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26
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Debus RJ, Oyala PH. Independent Mutation of Two Bridging Carboxylate Ligands Stabilizes Alternate Conformers of the Photosynthetic O 2-Evolving Mn 4CaO 5 Cluster in Photosystem II. J Phys Chem B 2024; 128:3870-3884. [PMID: 38602496 DOI: 10.1021/acs.jpcb.4c00829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
The O2-evolving Mn4CaO5 cluster in photosystem II is ligated by six carboxylate residues. One of these is D170 of the D1 subunit. This carboxylate bridges between one Mn ion (Mn4) and the Ca ion. A second carboxylate ligand is D342 of the D1 subunit. This carboxylate bridges between two Mn ions (Mn1 and Mn2). D170 and D342 are located on opposite sides of the Mn4CaO5 cluster. Recently, it was shown that the D170E mutation perturbs both the intricate networks of H-bonds that surround the Mn4CaO5 cluster and the equilibrium between different conformers of the cluster in two of its lower oxidation states, S1 and S2, while still supporting O2 evolution at approximately 50% the rate of the wild type. In this study, we show that the D342E mutation produces much the same alterations to the cluster's FTIR and EPR spectra as D170E, while still supporting O2 evolution at approximately 20% the rate of the wild type. Furthermore, the double mutation, D170E + D342E, behaves similarly to the two single mutations. We conclude that D342E alters the equilibrium between different conformers of the cluster in its S1 and S2 states in the same manner as D170E and perturbs the H-bond networks in a similar fashion. This is the second identification of a Mn4CaO5 metal ligand whose mutation influences the equilibrium between the different conformers of the S1 and S2 states without eliminating O2 evolution. This finding has implications for our understanding of the mechanism of O2 formation in terms of catalytically active/inactive conformations of the Mn4CaO5 cluster in its lower oxidation states.
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Affiliation(s)
- Richard J Debus
- Department of Biochemistry, University of California at Riverside, Riverside, California 92521, United States
| | - Paul H Oyala
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91106, United States
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27
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Semin B, Loktyushkin A, Lovyagina E. Current analysis of cations substitution in the oxygen-evolving complex of photosystem II. Biophys Rev 2024; 16:237-247. [PMID: 38737202 PMCID: PMC11078907 DOI: 10.1007/s12551-024-01186-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 03/27/2024] [Indexed: 05/14/2024] Open
Abstract
Water oxidation in photosystem II (PSII) is performed by the oxygen-evolving complex Mn4CaO5 which can be extracted from PSII and then reconstructed using exogenous cations Mn(II) and Ca2+. The binding efficiency of other cations to the Mn-binding sites in Mn-depleted PSII was investigated without any positive results. At the same time, a study of the Fe cations interaction with Mn-binding sites showed that it binds at a level comparable with the binding of Mn cations. Binding of Fe(II) cations first requires its light-dependent oxidation. In general, the interaction of Fe(II) with Mn-depleted PSII has a number of features similar to the two-quantum model of photoactivation of the complex with the release of oxygen. Interestingly, incubation of Ca-depleted PSII with Fe(II) cations under certain conditions is accompanied by the formation of a chimeric cluster Mn/Fe in the oxygen-evolving complex. PSII with the cluster 2Mn2Fe was found to be capable of water oxidation, but only to the H2O2 intermediate. However, the cluster 3Mn1Fe can oxidize water to O2 with an efficiency about 25% of the original in the absence of extrinsic proteins PsbQ and PsbP. In the presence of these proteins, the efficiency of O2 evolution can reach 80% of the original when adding exogenous Ca2+. In this review, we summarized information on the formation of chimeric Mn-Fe clusters in the oxygen-evolving complex. The data cited may be useful for detailing the mechanism of water oxidation.
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Affiliation(s)
- Boris Semin
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia 119234
| | - Aleksey Loktyushkin
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia 119234
| | - Elena Lovyagina
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia 119234
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28
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Smith N, Dasgupta M, Wych DC, Dolamore C, Sierra RG, Lisova S, Marchany-Rivera D, Cohen AE, Boutet S, Hunter MS, Kupitz C, Poitevin F, Moss FR, Mittan-Moreau DW, Brewster AS, Sauter NK, Young ID, Wolff AM, Tiwari VK, Kumar N, Berkowitz DB, Hadt RG, Thompson MC, Follmer AH, Wall ME, Wilson MA. Changes in an enzyme ensemble during catalysis observed by high-resolution XFEL crystallography. SCIENCE ADVANCES 2024; 10:eadk7201. [PMID: 38536910 PMCID: PMC10971408 DOI: 10.1126/sciadv.adk7201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 02/21/2024] [Indexed: 04/01/2024]
Abstract
Enzymes populate ensembles of structures necessary for catalysis that are difficult to experimentally characterize. We use time-resolved mix-and-inject serial crystallography at an x-ray free electron laser to observe catalysis in a designed mutant isocyanide hydratase (ICH) enzyme that enhances sampling of important minor conformations. The active site exists in a mixture of conformations, and formation of the thioimidate intermediate selects for catalytically competent substates. The influence of cysteine ionization on the ICH ensemble is validated by determining structures of the enzyme at multiple pH values. Large molecular dynamics simulations in crystallo and time-resolved electron density maps show that Asp17 ionizes during catalysis and causes conformational changes that propagate across the dimer, permitting water to enter the active site for intermediate hydrolysis. ICH exhibits a tight coupling between ionization of active site residues and catalysis-activated protein motions, exemplifying a mechanism of electrostatic control of enzyme dynamics.
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Affiliation(s)
- Nathan Smith
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Medhanjali Dasgupta
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - David C. Wych
- Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 875405, USA
- Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Cole Dolamore
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Raymond G. Sierra
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Stella Lisova
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Darya Marchany-Rivera
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Aina E. Cohen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Mark S. Hunter
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Christopher Kupitz
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Frédéric Poitevin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Frank R. Moss
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - David W. Mittan-Moreau
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Aaron S. Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Nicholas K. Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Iris D. Young
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Alexander M. Wolff
- Department of Chemistry and Biochemistry, University of California, Merced, CA 95340, USA
| | - Virendra K. Tiwari
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Nivesh Kumar
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - David B. Berkowitz
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Ryan G. Hadt
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Michael C. Thompson
- Department of Chemistry and Biochemistry, University of California, Merced, CA 95340, USA
| | - Alec H. Follmer
- Department of Chemistry, University of California-Irvine, Irvine, CA 92697, USA
| | - Michael E. Wall
- Computer, Computational, and Statistical Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 875405, USA
| | - Mark A. Wilson
- Department of Biochemistry and Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
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29
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Yamasaki H, Itoh RD, Mizumoto KB, Yoshida YS, Otaki JM, Cohen MF. Spatiotemporal Characteristics Determining the Multifaceted Nature of Reactive Oxygen, Nitrogen, and Sulfur Species in Relation to Proton Homeostasis. Antioxid Redox Signal 2024. [PMID: 38407968 DOI: 10.1089/ars.2023.0544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Significance: Reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species (RSS) act as signaling molecules, regulating gene expression, enzyme activity, and physiological responses. However, excessive amounts of these molecular species can lead to deleterious effects, causing cellular damage and death. This dual nature of ROS, RNS, and RSS presents an intriguing conundrum that calls for a new paradigm. Recent Advances: Recent advancements in the study of photosynthesis have offered significant insights at the molecular level and with high temporal resolution into how the photosystem II oxygen-evolving complex manages to prevent harmful ROS production during the water-splitting process. These findings suggest that a dynamic spatiotemporal arrangement of redox reactions, coupled with strict regulation of proton transfer, is crucial for minimizing unnecessary ROS formation. Critical Issues: To better understand the multifaceted nature of these reactive molecular species in biology, it is worth considering a more holistic view that combines ecological and evolutionary perspectives on ROS, RNS, and RSS. By integrating spatiotemporal perspectives into global, cellular, and biochemical events, we discuss local pH or proton availability as a critical determinant associated with the generation and action of ROS, RNS, and RSS in biological systems. Future Directions: The concept of localized proton availability will not only help explain the multifaceted nature of these ubiquitous simple molecules in diverse systems but also provide a basis for new therapeutic strategies to manage and manipulate these reactive species in neural disorders, pathogenic diseases, and antiaging efforts.
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Affiliation(s)
- Hideo Yamasaki
- Faculty of Science, University of the Ryukyus, Okinawa, Japan
| | - Ryuuichi D Itoh
- Faculty of Science, University of the Ryukyus, Okinawa, Japan
| | | | - Yuki S Yoshida
- Faculty of Science, University of the Ryukyus, Okinawa, Japan
| | - Joji M Otaki
- Faculty of Science, University of the Ryukyus, Okinawa, Japan
| | - Michael F Cohen
- University of California Cooperative Extension, Santa Clara County, San Jose, California, USA
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30
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Chernev P, Aydin AO, Messinger J. On the simulation and interpretation of substrate-water exchange experiments in photosynthetic water oxidation. PHOTOSYNTHESIS RESEARCH 2024:10.1007/s11120-024-01084-8. [PMID: 38512410 DOI: 10.1007/s11120-024-01084-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/01/2024] [Indexed: 03/23/2024]
Abstract
Water oxidation by photosystem II (PSII) sustains most life on Earth, but the molecular mechanism of this unique process remains controversial. The ongoing identification of the binding sites and modes of the two water-derived substrate oxygens ('substrate waters') in the various intermediates (Si states, i = 0, 1, 2, 3, 4) that the water-splitting tetra-manganese calcium penta-oxygen (Mn4CaO5) cluster attains during the reaction cycle provides central information towards resolving the unique chemistry of biological water oxidation. Mass spectrometric measurements of single- and double-labeled dioxygen species after various incubation times of PSII with H218O provide insight into the substrate binding modes and sites via determination of exchange rates. Such experiments have revealed that the two substrate waters exchange with different rates that vary independently with the Si state and are hence referred to as the fast (Wf) and the slow (WS) substrate waters. New insight for the molecular interpretation of these rates arises from our recent finding that in the S2 state, under special experimental conditions, two different rates of WS exchange are observed that appear to correlate with the high spin and low spin conformations of the Mn4CaO5 cluster. Here, we reexamine and unite various proposed methods for extracting and assigning rate constants from this recent data set. The analysis results in a molecular model for substrate-water binding and exchange that reconciles the expected non-exchangeability of the central oxo bridge O5 when located between two Mn(IV) ions with the experimental and theoretical assignment of O5 as WS in all S states. The analysis also excludes other published proposals for explaining the water exchange kinetics.
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Affiliation(s)
- Petko Chernev
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, 75120, Uppsala, Sweden
| | - A Orkun Aydin
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, 75120, Uppsala, Sweden
| | - Johannes Messinger
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, 75120, Uppsala, Sweden.
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31
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Müh F, Bothe A, Zouni A. Towards understanding the crystallization of photosystem II: influence of poly(ethylene glycol) of various molecular sizes on the micelle formation of alkyl maltosides. PHOTOSYNTHESIS RESEARCH 2024:10.1007/s11120-024-01079-5. [PMID: 38488943 DOI: 10.1007/s11120-024-01079-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 01/24/2024] [Indexed: 03/17/2024]
Abstract
The influence of poly(ethylene glycol) (PEG) polymers H-(O-CH2-CH2)p-OH with different average molecular sizes p on the micelle formation of n-alkyl-β-D-maltoside detergents with the number of carbon atoms in the alkyl chain ranging from 10 to 12 is investigated with the aim to learn more about the detergent behavior under conditions suitable for the crystallization of the photosynthetic pigment-protein complex photosystem II. PEG is shown to increase the critical micelle concentration (CMC) of all three detergents in the crystallization buffer in a way that the free energy of micelle formation increases linearly with the concentration of oxyethylene units (O-CH2-CH2) irrespective of the actual molecular weight of the polymer. The CMC shift is modeled by assuming for simplicity that it is dominated by the interaction between PEG and detergent monomers and is interpreted in terms of an increase of the transfer free energy of a methylene group of the alkyl chain by 0.2 kJ mol-1 per 1 mol L-1 increase of the concentration of oxyethylene units at 298 K. Implications of this effect for the solubilization and crystallization of protein-detergent complexes as well as detergent extraction from crystals are discussed.
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Affiliation(s)
- Frank Müh
- Institut für Theoretische Physik, Johannes Kepler Universität Linz, Altenberger Strasse 69, 4040, Linz, Austria.
| | - Adrian Bothe
- Institut für Molekularbiologie und Biophysik, ETH Zürich, HPK, Otto-Stern-Weg 5, CH-8093, Zurich, Switzerland
| | - Athina Zouni
- Institut für Biologie, Humboldt Universität zu Berlin, Leonor-Michaelis-Haus, Philippstrasse 13, 10095, Berlin, Germany
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32
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Kaur D, Reiss K, Wang J, Batista VS, Brudvig GW, Gunner MR. Occupancy Analysis of Water Molecules inside Channels within 25 Å Radius of the Oxygen-Evolving Center of Photosystem II in Molecular Dynamics Simulations. J Phys Chem B 2024; 128:2236-2248. [PMID: 38377592 DOI: 10.1021/acs.jpcb.3c05367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
At room temperature and neutral pH, the oxygen-evolving center (OEC) of photosystem II (PSII) catalyzes water oxidation. During this process, oxygen is released from the OEC, while substrate waters are delivered to the OEC and protons are passed from the OEC to the lumen through water channels known as the narrow or the O4 channel, broad or the Cl1 channel, and large or the O1 channel. Protein residues lining the surfaces of these channels play a critical role in stabilizing the hydrogen-bonding networks that assist in the process. We carried out an occupancy analysis to better understand the structural and possible substrate water dynamics in full PSII monomer molecular dynamics (MD) trajectories in both the S1 and S2 states. We find that the equilibrated positions of water molecules derived from MD-derived electron density maps largely match the experimentally observed positions in crystallography. Furthermore, the occupancy reduction in MD simulations of some water molecules inside the single-filed narrow channel also correlates well with the crystallographic data during a structural transition when the S1 state of the OEC advances to the S2 state. The overall reduced occupancies of water molecules are the source of their "vacancy-hopping" dynamic nature inside these channels, unlike water molecules inside an ice lattice where all water molecules have a fixed unit occupancy. We propose on the basis of findings in our structural and molecular dynamics analysis that the water molecule occupying a pocket formed by D1-D61, D1-S169, and O4 of the OEC could be the last steppingstone to enter into the OEC and that the broad channel may be favored for proton transfer.
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Affiliation(s)
- Divya Kaur
- Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines L2S 3A1, Ontario, Canada
| | - Krystle Reiss
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, United States
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - M R Gunner
- Department of Physics, City College of New York New York, New York 10031, United States
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33
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Lin C, Mazor Y, Reppert M. Feeling the Strain: Quantifying Ligand Deformation in Photosynthesis. J Phys Chem B 2024; 128:2266-2280. [PMID: 38442033 DOI: 10.1021/acs.jpcb.3c06488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Structural distortion of protein-bound ligands can play a critical role in enzyme function by tuning the electronic and chemical properties of the ligand molecule. However, quantifying these effects is difficult due to the limited resolution of protein structures and the difficulty of generating accurate structural restraints for nonprotein ligands. Here, we seek to quantify these effects through a statistical analysis of ligand distortion in chlorophyll proteins (CP), where ring deformation is thought to play a role in energy and electron transfer. To assess the accuracy of ring-deformation estimates from available structural data, we take advantage of the C2 symmetry of photosystem II (PSII), comparing ring-deformation estimates for equivalent sites both within and between 113 distinct X-ray and cryogenic electron microscopy PSII structures. Significantly, we find that several deformation modes exhibit considerable variability in predictions, even for equivalent monomers, down to a 2 Å resolution, to an extent that probably prevents their utilization in optical calculations. We further find that refinement restraints play a critical role in determining deformation values to resolution as low as 2 Å. However, for those modes that are well-resolved in the structural data, ring deformation in PSII is strongly conserved across all species tested from cyanobacteria to algae. These results highlight both the opportunities and limitations inherent in structure-based analyses of the bioenergetic and optical properties of CPs and other protein-ligand complexes.
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Affiliation(s)
- Chientzu Lin
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47920, United States
| | - Yuval Mazor
- School of Molecular Sciences, The Biodesign Institute, Arizona State University, Tempe, Arizona 85281, United States
| | - Mike Reppert
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47920, United States
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de Lichtenberg C, Rapatskiy L, Reus M, Heyno E, Schnegg A, Nowaczyk MM, Lubitz W, Messinger J, Cox N. Assignment of the slowly exchanging substrate water of nature's water-splitting cofactor. Proc Natl Acad Sci U S A 2024; 121:e2319374121. [PMID: 38437550 PMCID: PMC10945779 DOI: 10.1073/pnas.2319374121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/12/2024] [Indexed: 03/06/2024] Open
Abstract
Identifying the two substrate water sites of nature's water-splitting cofactor (Mn4CaO5 cluster) provides important information toward resolving the mechanism of O-O bond formation in Photosystem II (PSII). To this end, we have performed parallel substrate water exchange experiments in the S1 state of native Ca-PSII and biosynthetically substituted Sr-PSII employing Time-Resolved Membrane Inlet Mass Spectrometry (TR-MIMS) and a Time-Resolved 17O-Electron-electron Double resonance detected NMR (TR-17O-EDNMR) approach. TR-MIMS resolves the kinetics for incorporation of the oxygen-isotope label into the substrate sites after addition of H218O to the medium, while the magnetic resonance technique allows, in principle, the characterization of all exchangeable oxygen ligands of the Mn4CaO5 cofactor after mixing with H217O. This unique combination shows i) that the central oxygen bridge (O5) of Ca-PSII core complexes isolated from Thermosynechococcus vestitus has, within experimental conditions, the same rate of exchange as the slowly exchanging substrate water (WS) in the TR-MIMS experiments and ii) that the exchange rates of O5 and WS are both enhanced by Ca2+→Sr2+ substitution in a similar manner. In the context of previous TR-MIMS results, this shows that only O5 fulfills all criteria for being WS. This strongly restricts options for the mechanism of water oxidation.
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Affiliation(s)
- Casper de Lichtenberg
- Department of Chemistry- Ångström Laboratorium, Uppsala University, UppsalaS-75120, Sweden
- Department of Chemistry, Chemical Biological Centre, Umeå University, UmeåS-90187, Sweden
| | - Leonid Rapatskiy
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
| | - Michael Reus
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
| | - Eiri Heyno
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
| | - Alexander Schnegg
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
| | - Marc M. Nowaczyk
- Department of Plant Biochemistry, Ruhr-Universität Bochum, BochumD-44780, Germany
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
| | - Johannes Messinger
- Department of Chemistry- Ångström Laboratorium, Uppsala University, UppsalaS-75120, Sweden
- Department of Chemistry, Chemical Biological Centre, Umeå University, UmeåS-90187, Sweden
| | - Nicholas Cox
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der RuhrD-45470, Germany
- Research School of Chemistry, Australian National University, Acton ACT2601, Australia
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35
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Noguchi T. Mechanism of Proton Transfer through the D1-E65/D2-E312 Gate during Photosynthetic Water Oxidation. J Phys Chem B 2024; 128:1866-1875. [PMID: 38364371 DOI: 10.1021/acs.jpcb.3c07787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2024]
Abstract
In photosystem II, the D1-E65/D2-E312 dyad in the Cl-1 channel has been proposed to play a pivotal role in proton transfer during water oxidation. However, the precise mechanism remains elusive. Here, the proton transfer mechanism within the Cl-1 channel was investigated using quantum mechanics/molecular mechanics calculations. The molecular vibration of the E65/E312 dyad and its deuteration effect revealed that the recently suggested stepwise proton transfer, i.e., initial proton release from the dyad followed by slow reprotonation, does not occur in the Cl-1 channel. Instead, proton transfer is proposed to take place via a conformational change at the E65/E312 dyad, acting as a gate. In its closed form, a proton is trapped within the dyad, preventing forward proton transfer. This closed form converts into the open form, where protonated D1-E65 provides a hydrogen bond to the water network, thereby facilitating fast Grotthuss-type proton transfer.
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Affiliation(s)
- Takumi Noguchi
- Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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36
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Drosou M, Pantazis DA. Comprehensive Evaluation of Models for Ammonia Binding to the Oxygen Evolving Complex of Photosystem II. J Phys Chem B 2024; 128:1333-1349. [PMID: 38299511 PMCID: PMC10875651 DOI: 10.1021/acs.jpcb.3c06304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 01/08/2024] [Accepted: 01/17/2024] [Indexed: 02/02/2024]
Abstract
The identity and insertion pathway of the substrate oxygen atoms that are coupled to dioxygen by the oxygen-evolving complex (OEC) remains a central question toward understanding Nature's water oxidation mechanism. In several studies, ammonia has been used as a small "water analogue" to elucidate the pathway of substrate access to the OEC and to aid in determining which of the oxygen ligands of the tetramanganese cluster are substrates for O-O bond formation. On the basis of structural and spectroscopic investigations, five first-sphere binding modes of ammonia have been suggested, involving either substitution of an existing H2O/OH-/O2- group or addition as an extra ligand to a metal ion of the Mn4CaO5 cluster. Some of these modes, specifically the ones involving substitution, have already been subject to spectroscopy-oriented quantum chemical investigations, whereas more recent suggestions that postulate the addition of ammonia have not been examined so far with quantum chemistry for their agreement with spectroscopic data. Herein, we use a common structural framework and theoretical methodology to evaluate structural models of the OEC that represent all proposed modes of first-sphere ammonia interaction with the OEC in its S2 state. Criteria include energetic, magnetic, kinetic, and spectroscopic properties compared against available experimental EPR, ENDOR, ESEEM, and EDNMR data. Our results show that models featuring ammonia replacing one of the two terminal water ligands on Mn4 align best with experimental data, while they definitively exclude substitution of a bridging μ-oxo ligand as well as incorporation of ammonia as a sixth ligand on Mn1 or Mn4.
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Affiliation(s)
- Maria Drosou
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
- Inorganic
Chemistry Laboratory, National and Kapodistrian
University of Athens, Panepistimiopolis, Zografou 15771, Greece
| | - Dimitrios A. Pantazis
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr 45470, Germany
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37
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Amin M, Kaur D, Brudvig GW, Brooks BR. Mapping the Oxygens in the Oxygen-Evolving Complex of Photosystem II by Their Nucleophilicity Using Quantum Descriptors. J Chem Theory Comput 2024. [PMID: 38306696 DOI: 10.1021/acs.jctc.3c00926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2024]
Abstract
The oxygen-evolving complex (OEC) of Photosystem II catalyzes the water-splitting reaction using solar energy. Thus, understanding the reaction mechanism will inspire the design of biomimetic artificial catalysts that convert solar energy to chemical energy. Conceptual Density Functional Theory (CDFT) focuses on understanding the reactivity of molecules and the atomic contribution to the overall nucleophilicity and electrophilicity of the molecule using quantum descriptors. However, this method has not been applied to the OEC before. Here, we use Fukui functions and the dual descriptor to provide quantitative measures of the nucleophilicity and electrophilicity of oxygens in the OEC for different models in different S states. Our results show that the μ-oxo bridges connected to terminal Mn4 are nucleophilic, and those in the cube formed by Mn1, Mn2, and Mn3 are mostly electrophilic. The dual descriptors of the bridging oxygens in the OEC showed a similar reactivity to that of bridging oxygens in Mn model compounds. However, the terminal water W1, which is bound to Mn4, showed very strong reactivity in some of the S3 models. Thus, our calculations support the model that proposes the formation of the O2 molecule through nucleophilic attack by a terminal water.
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Affiliation(s)
- Muhamed Amin
- Laboratory of Computational Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
- Department of Sciences, University College Groningen, University of Groningen, 9718 BG Groningen, The Netherlands
| | - Divya Kaur
- Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario, Canada L2S 3A1
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Bernard R Brooks
- Laboratory of Computational Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
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38
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Li H, Nakajima Y, Nango E, Owada S, Yamada D, Hashimoto K, Luo F, Tanaka R, Akita F, Kato K, Kang J, Saitoh Y, Kishi S, Yu H, Matsubara N, Fujii H, Sugahara M, Suzuki M, Masuda T, Kimura T, Thao TN, Yonekura S, Yu LJ, Tosha T, Tono K, Joti Y, Hatsui T, Yabashi M, Kubo M, Iwata S, Isobe H, Yamaguchi K, Suga M, Shen JR. Oxygen-evolving photosystem II structures during S 1-S 2-S 3 transitions. Nature 2024; 626:670-677. [PMID: 38297122 PMCID: PMC10866707 DOI: 10.1038/s41586-023-06987-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 12/15/2023] [Indexed: 02/02/2024]
Abstract
Photosystem II (PSII) catalyses the oxidation of water through a four-step cycle of Si states (i = 0-4) at the Mn4CaO5 cluster1-3, during which an extra oxygen (O6) is incorporated at the S3 state to form a possible dioxygen4-7. Structural changes of the metal cluster and its environment during the S-state transitions have been studied on the microsecond timescale. Here we use pump-probe serial femtosecond crystallography to reveal the structural dynamics of PSII from nanoseconds to milliseconds after illumination with one flash (1F) or two flashes (2F). YZ, a tyrosine residue that connects the reaction centre P680 and the Mn4CaO5 cluster, showed structural changes on a nanosecond timescale, as did its surrounding amino acid residues and water molecules, reflecting the fast transfer of electrons and protons after flash illumination. Notably, one water molecule emerged in the vicinity of Glu189 of the D1 subunit of PSII (D1-E189), and was bound to the Ca2+ ion on a sub-microsecond timescale after 2F illumination. This water molecule disappeared later with the concomitant increase of O6, suggesting that it is the origin of O6. We also observed concerted movements of water molecules in the O1, O4 and Cl-1 channels and their surrounding amino acid residues to complete the sequence of electron transfer, proton release and substrate water delivery. These results provide crucial insights into the structural dynamics of PSII during S-state transitions as well as O-O bond formation.
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Affiliation(s)
- Hongjie Li
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Yoshiki Nakajima
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Eriko Nango
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan
- RIKEN SPring-8 Center, Sayo, Japan
| | - Shigeki Owada
- Japan Synchrotron Radiation Research Institute, Sayo, Japan
| | - Daichi Yamada
- Department of Picobiology, Graduate School of Life Science, University of Hyogo, Kobe, Japan
| | - Kana Hashimoto
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Fangjia Luo
- Japan Synchrotron Radiation Research Institute, Sayo, Japan
| | - Rie Tanaka
- RIKEN SPring-8 Center, Sayo, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Fusamichi Akita
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Koji Kato
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | | | - Yasunori Saitoh
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Shunpei Kishi
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Huaxin Yu
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Naoki Matsubara
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Hajime Fujii
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | | | - Mamoru Suzuki
- Institute for Protein Research, Osaka University, Osaka, Japan
| | - Tetsuya Masuda
- Division of Food and Nutrition, Faculty of Agriculture, Ryukoku University, Otsu, Japan
| | - Tetsunari Kimura
- Department of Chemistry, Graduate School of Science, Kobe University, Kobe, Japan
| | - Tran Nguyen Thao
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Shinichiro Yonekura
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Long-Jiang Yu
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | | | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute, Sayo, Japan
| | - Yasumasa Joti
- Japan Synchrotron Radiation Research Institute, Sayo, Japan
| | - Takaki Hatsui
- Japan Synchrotron Radiation Research Institute, Sayo, Japan
| | - Makina Yabashi
- Japan Synchrotron Radiation Research Institute, Sayo, Japan
| | - Minoru Kubo
- Department of Picobiology, Graduate School of Life Science, University of Hyogo, Kobe, Japan
| | - So Iwata
- RIKEN SPring-8 Center, Sayo, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroshi Isobe
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan
| | - Kizashi Yamaguchi
- Center for Quantum Information and Quantum Biology, Osaka University, Osaka, Japan
| | - Michihiro Suga
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
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39
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Caramello N, Royant A. From femtoseconds to minutes: time-resolved macromolecular crystallography at XFELs and synchrotrons. Acta Crystallogr D Struct Biol 2024; 80:60-79. [PMID: 38265875 PMCID: PMC10836399 DOI: 10.1107/s2059798323011002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 12/21/2023] [Indexed: 01/26/2024] Open
Abstract
Over the last decade, the development of time-resolved serial crystallography (TR-SX) at X-ray free-electron lasers (XFELs) and synchrotrons has allowed researchers to study phenomena occurring in proteins on the femtosecond-to-minute timescale, taking advantage of many technical and methodological breakthroughs. Protein crystals of various sizes are presented to the X-ray beam in either a static or a moving medium. Photoactive proteins were naturally the initial systems to be studied in TR-SX experiments using pump-probe schemes, where the pump is a pulse of visible light. Other reaction initiations through small-molecule diffusion are gaining momentum. Here, selected examples of XFEL and synchrotron time-resolved crystallography studies will be used to highlight the specificities of the various instruments and methods with respect to time resolution, and are compared with cryo-trapping studies.
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Affiliation(s)
- Nicolas Caramello
- Structural Biology Group, European Synchrotron Radiation Facility, 1 Avenue des Martyrs, CS 40220, 38043 Grenoble CEDEX 9, France
- Hamburg Centre for Ultrafast Imaging, Universität Hamburg, HARBOR, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Antoine Royant
- Structural Biology Group, European Synchrotron Radiation Facility, 1 Avenue des Martyrs, CS 40220, 38043 Grenoble CEDEX 9, France
- Université Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), 71 Avenue des Martyrs, CS 10090, 38044 Grenoble CEDEX 9, France
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40
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Bhattacharya P, Bag R, Butcher RJ, Behera S, Mondal B, Goswami S. Chemistry of a series of heterobimetallic complexes MnIII2(Ca II/Sr II)X 2 (X = Cl -, Br -). Dalton Trans 2024; 53:2324-2332. [PMID: 38205727 DOI: 10.1039/d3dt01858j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
This manuscript describes the syntheses, structures and magnetism of MnIII-CaII/SrII complexes which are compositionally relevant in the context of the oxygen evolving complex (OEC) of photosystem II (PS II). A series of trimetallic tetraoxo complexes containing redox-inactive metal ions CaII or SrII were synthesized using a tetranucleating ligand framework. The structural characteristics of these complexes, with the oxido ligands bridging the redox-inactive metals and the manganese centres, make them particularly relevant to biological and heterogeneous metal-oxido clusters. Electrochemical studies of these compounds show that the reduction potentials are highly dependent upon the Lewis acidity of the redox-inactive metal, identifying the chemical basis for the observed differences in electrochemistry. This correlation provides insights into the role of the CaII/SrII ion in modulating the redox potential of the OEC and of other redox-inactive ions in tuning the redox potentials of other metal-oxide electrocatalysts. Temperature dependent magnetic measurements have also been performed for the complexes.
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Affiliation(s)
| | - Riya Bag
- Department of Chemistry, University of Calcutta, 92, A.P.C. Road, Kolkata-700009, India.
| | - Ray J Butcher
- Chemistry Department, Howard University, Washington, D.C. 20059, USA
| | - Snehanjali Behera
- Discipline of Chemistry, IIT Gandhinagar, Palaj, Gujarat - 382055, India
| | - Biswajit Mondal
- Discipline of Chemistry, IIT Gandhinagar, Palaj, Gujarat - 382055, India
| | - Sanchita Goswami
- Department of Chemistry, University of Calcutta, 92, A.P.C. Road, Kolkata-700009, India.
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41
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Rummel F, Malcomson T, Barchenko M, O’Malley PJ. Insights into PSII's S 3Y Z• State: An Electronic and Magnetic Analysis. J Phys Chem Lett 2024; 15:499-506. [PMID: 38190694 PMCID: PMC10801681 DOI: 10.1021/acs.jpclett.3c03026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 12/27/2023] [Accepted: 01/02/2024] [Indexed: 01/10/2024]
Abstract
Using BS-DFT (broken-symmetry density functional theory), the electronic and magnetic properties of the S3YZ• state of photosystem II were investigated and compared to those of the S3 state. While the O5 oxo-O6 hydroxo species presents little difference between the two states, a previously identified [O5O6]3- exhibits reduced stabilization of the O5-O6 shared spin. This species is shown to have some coupling with the YZ• center through Mn1 and O6. Similarly, a peroxo species is found to exhibit significant exchange couplings between the YZ• center and the Mn cluster through Mn1. Mechanistic changes in O-O bond formation in S3YZ• are highlighted by analysis of IBOs (intrinsic bonding orbitals) showing deviation for Mn1 and O6 centered IBOs. This change in coupling interactions throughout the complex as a result of S3YZ• formation presents implications for the determination of the mechanism spanning the end of the S3 and the start of the S4 states, affecting both electron movement and oxygen bond formation.
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Affiliation(s)
- Felix Rummel
- Department
of Chemistry, School of Natural Sciences, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Thomas Malcomson
- School
of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, United Kingdom
| | - Maxim Barchenko
- Department
of Chemistry, School of Natural Sciences, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Patrick J. O’Malley
- Department
of Chemistry, School of Natural Sciences, The University of Manchester, Manchester M13 9PL, United Kingdom
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42
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Ezhov R, Bury G, Maximova O, Grant ED, Kondo M, Masaoka S, Pushkar Y. Pentanuclear iron complex for water oxidation: spectroscopic analysis of reactive intermediates in solution and catalyst immobilization into the MOF-based photoanode. J Catal 2024; 429:115230. [PMID: 38187083 PMCID: PMC10769158 DOI: 10.1016/j.jcat.2023.115230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Photoelectrochemical water splitting can produce green hydrogen for industrial use and CO2-neutral transportation, ensuring the transition from fossil fuels to green, renewable energy sources. The iron-based electrocatalyst [FeII4FeIII(μ-3-O)(μ-L)6]3+ (LH = 3,5-bis(2-pyridyl)pyrazole) (1), discovered in 2016, is one of the fastest molecular water oxidation catalysts (WOC) based on earth-abundant elements. However, its water oxidation reaction mechanism has not been yet fully elucidated. Here, we present in situ X-ray spectroscopy and electron paramagnetic resonance (EPR) analysis of electrochemical water oxidation reaction (WOR) promoted by (1) in water-acetonitrile solution. We observed transient reactive intermediates during the in situ electrochemical WOR, consistent with a coordination sphere expansion prior to the onset of catalytic current. At a pre-catalytic (~+1.1 V vs. Ag/AgCl) potential, the distinct g~2.0 EPR signal assigned to FeIII/FeIV interaction was observed. Prolonged bulk electrolysis at catalytic (~+1.6 V vs. Ag/AgCl) potential leads to the further oxidation of Fe centers in (1). At the steady state achieved with such electrolysis, the formation of hypervalent FeV=O and FeIV=O catalytic intermediates was inferred with XANES and EXAFS fitting, detecting a short Fe=O bond at ~1.6 Å. (1) was embedded into MIL-126 MOF with the formation of (1)-MIL-126 composite. The latter was tested in photoelectrochemical WOR and demonstrated an improvement of electrocatalytic current upon visible light irradiation in acidic (pH=2) water solution. The presented spectroscopic analysis gives further insight into the catalytic pathways of multinuclear systems and should help the subsequent development of more energy- and cost-effective catalysts of water splitting based on earth-abundant metals. Photoelectrocatalytic activity of (1)-MIL-126 confirms the possibility of creating an assembly of (1) inside a solid support and boosting it with solar irradiation towards industrial applications of the catalyst.
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Affiliation(s)
- Roman Ezhov
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 USA
| | - Gabriel Bury
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 USA
| | - Olga Maximova
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 USA
| | - Elliot Daniel Grant
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 USA
| | - Mio Kondo
- Division of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shigeyuki Masaoka
- Division of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yulia Pushkar
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 USA
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43
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Saito K, Nishio S, Ishikita H. Interplay of two low-barrier hydrogen bonds in long-distance proton-coupled electron transfer for water oxidation. PNAS NEXUS 2023; 2:pgad423. [PMID: 38130665 PMCID: PMC10733176 DOI: 10.1093/pnasnexus/pgad423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/20/2023] [Indexed: 12/23/2023]
Abstract
D1-Tyr161 (TyrZ) forms a low-barrier H-bond with D1-His190 and functions as a redox-active group in photosystem II. When oxidized to the radical form (TyrZ-O•), it accepts an electron from the oxygen-evolving Mn4CaO5 cluster, facilitating an increase in the oxidation state (Sn; n = 0-3). In this study, we investigated the mechanism of how TyrZ-O• drives proton-coupled electron transfer during the S2 to S3 transition using a quantum mechanical/molecular mechanical approach. In response to TyrZ-O• formation and subsequent loss of the low-barrier H-bond, the ligand water molecule at the Ca2+ site (W4) reorients away from TyrZ and donates an H-bond to D1-Glu189 at Mn4 of Mn4CaO5 together with an adjacent water molecule. The H-bond donation to the Mn4CaO5 cluster triggers the release of the proton from the lowest pKa site (W1 at Mn4) along the W1…D1-Asp61 low-barrier H-bond, leading to protonation of D1-Asp61. The interplay of the two low-barrier H-bonds, involving the Ca2+ interface and forming the extended Grotthuss-like network [TyrZ…D1-His190]-[Mn4CaO5]-[W1…D1-Asp61], rather than the direct electrostatic interaction, is likely a basis of the apparent long-distance interaction (11.4 Å) between TyrZ-O• formation and D1-Asp61 protonation.
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Affiliation(s)
- Keisuke Saito
- Department of Applied Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904, Japan
| | - Shunya Nishio
- Department of Applied Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Hiroshi Ishikita
- Department of Applied Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research Center for Advanced Science and Technology, The University of Tokyo, Meguro-ku, Tokyo 153-8904, Japan
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44
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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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45
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Yamaguchi K, Miyagawa K, Shoji M, Kawakami T, Isobe H, Yamanaka S, Nakajima T. Theoretical elucidation of the structure, bonding, and reactivity of the CaMn 4O x clusters in the whole Kok cycle for water oxidation embedded in the oxygen evolving center of photosystem II. New molecular and quantum insights into the mechanism of the O-O bond formation. PHOTOSYNTHESIS RESEARCH 2023:10.1007/s11120-023-01053-7. [PMID: 37945776 DOI: 10.1007/s11120-023-01053-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/25/2023] [Indexed: 11/12/2023]
Abstract
This paper reviews our historical developments of broken-symmetry (BS) and beyond BS methods that are applicable for theoretical investigations of metalloenzymes such as OEC in PSII. The BS hybrid DFT (HDFT) calculations starting from high-resolution (HR) XRD structure in the most stable S1 state have been performed to elucidate structure and bonding of whole possible intermediates of the CaMn4Ox cluster (1) in the Si (i = 0 ~ 4) states of the Kok cycle. The large-scale HDFT/MM computations starting from HR XRD have been performed to elucidate biomolecular system structures which are crucial for examination of possible water inlet and proton release pathways for water oxidation in OEC of PSII. DLPNO CCSD(T0) computations have been performed for elucidation of scope and reliability of relative energies among the intermediates by HDFT. These computations combined with EXAFS, XRD, XFEL, and EPR experimental results have elucidated the structure, bonding, and reactivity of the key intermediates, which are indispensable for understanding and explanation of the mechanism of water oxidation in OEC of PSII. Interplay between theory and experiments have elucidated important roles of four degrees of freedom, spin, charge, orbital, and nuclear motion for understanding and explanation of the chemical reactivity of 1 embedded in protein matrix, indicating the participations of the Ca(H2O)n ion and tyrosine(Yz)-O radical as a one-electron acceptor for the O-O bond formation. The Ca-assisted Yz-coupled O-O bond formation mechanisms for water oxidation are consistent with recent XES and very recent time-resolved SFX XFEL and FTIR results.
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Affiliation(s)
- Kizashi Yamaguchi
- Center for Quantum Information and Quantum Biology, Osaka University, Toyonaka, Osaka, 560-0043, Japan.
- RIKEN Center for Computational Science, Kobe, Hyogo, 650-0047, Japan.
- SANKEN, Osaka University, Ibaraki, Osaka, 567-0047, Japan.
| | - Koichi Miyagawa
- Center of Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan
| | - Mitsuo Shoji
- Center of Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan
| | - Takashi Kawakami
- RIKEN Center for Computational Science, Kobe, Hyogo, 650-0047, Japan
- Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Hiroshi Isobe
- Research Institute for Interdisciplinary Science, and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Shusuke Yamanaka
- Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Takahito Nakajima
- RIKEN Center for Computational Science, Kobe, Hyogo, 650-0047, Japan
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46
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Golub M, Pieper J. Recent Progress in Solution Structure Studies of Photosynthetic Proteins Using Small-Angle Scattering Methods. Molecules 2023; 28:7414. [PMID: 37959833 PMCID: PMC10650700 DOI: 10.3390/molecules28217414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 10/27/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
Utilized for gaining structural insights, small-angle neutron and X-ray scattering techniques (SANS and SAXS, respectively) enable an examination of biomolecules, including photosynthetic pigment-protein complexes, in solution at physiological temperatures. These methods can be seen as instrumental bridges between the high-resolution structural information achieved by crystallography or cryo-electron microscopy and functional explorations conducted in a solution state. The review starts with a comprehensive overview about the fundamental principles and applications of SANS and SAXS, with a particular focus on the recent advancements permitting to enhance the efficiency of these techniques in photosynthesis research. Among the recent developments discussed are: (i) the advent of novel modeling tools whereby a direct connection between SANS and SAXS data and high-resolution structures is created; (ii) the employment of selective deuteration, which is utilized to enhance spatial selectivity and contrast matching; (iii) the potential symbioses with molecular dynamics simulations; and (iv) the amalgamations with functional studies that are conducted to unearth structure-function relationships. Finally, reference is made to time-resolved SANS/SAXS experiments, which enable the monitoring of large-scale structural transformations of proteins in a real-time framework.
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Affiliation(s)
| | - Jörg Pieper
- Institute of Physics, University of Tartu, Wilhelm Ostwald Str. 1, 50411 Tartu, Estonia;
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Botha S, Fromme P. Review of serial femtosecond crystallography including the COVID-19 pandemic impact and future outlook. Structure 2023; 31:1306-1319. [PMID: 37898125 PMCID: PMC10842180 DOI: 10.1016/j.str.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/28/2023] [Accepted: 10/04/2023] [Indexed: 10/30/2023]
Abstract
Serial femtosecond crystallography (SFX) revolutionized macromolecular crystallography over the past decade by enabling the collection of X-ray diffraction data from nano- or micrometer sized crystals while outrunning structure-altering radiation damage effects at room temperature. The serial manner of data collection from millions of individual crystals coupled with the femtosecond duration of the ultrabright X-ray pulses enables time-resolved studies of macromolecules under near-physiological conditions to unprecedented temporal resolution. In 2020 the rapid spread of the coronavirus SARS-CoV-2 resulted in a global pandemic of coronavirus disease-2019. This led to a shift in how serial femtosecond experiments were performed, along with rapid funding and free electron laser beamtime availability dedicated to SARS-CoV-2-related studies. This review outlines the current state of SFX research, the milestones that were achieved, the impact of the global pandemic on this field as well as an outlook into exciting future directions.
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Affiliation(s)
- Sabine Botha
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287-5001, USA; Department of Physics, Arizona State University, Tempe, AZ 85287-1504, USA.
| | - Petra Fromme
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287-5001, USA; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, USA.
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48
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Gates C, Williams JM, Ananyev G, Dismukes GC. How chloride functions to enable proton conduction in photosynthetic water oxidation: Time-resolved kinetics of intermediates (S-states) in vivo and bromide substitution. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148998. [PMID: 37499962 DOI: 10.1016/j.bbabio.2023.148998] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/11/2023] [Accepted: 07/19/2023] [Indexed: 07/29/2023]
Abstract
Chloride (Cl-) is essential for O2 evolution during photosynthetic water oxidation. Two chlorides near the water-oxidizing complex (WOC) in Photosystem II (PSII) structures from Thermosynechococcus elongatus (and T. vulcanus) have been postulated to transfer protons generated from water oxidation. We monitored four criteria: primary charge separation flash yield (P* → P+QA-), rates of water oxidation steps (S-states), rate of proton evolution, and flash O2 yield oscillations by measuring chlorophyll variable fluorescence (P* quenching), pH-sensitive dye changes, and oximetry. Br-substitution slows and destabilizes cellular growth, resulting from lower light-saturated O2 evolution rate (-20 %) and proton release (-36 % ΔpH gradient). The latter implies less ATP production. In Br- cultures, protonogenic S-state transitions (S2 → S3 → S0') slow with increasing light intensity and during O2/water exchange (S0' → S0 → S1), while the non-protonogenic S1 → S2 transition is kinetically unaffected. As flash rate increases in Cl- cultures, both rate and extent of acidification of the lumen increase, while charge recombination is suppressed relative to Br-. The Cl- advantage in rapid proton escape from the WOC to lumen is attributed to correlated ion-pair movement of H3O+Cl- in dry water channels vs. separated Br- and H+ ion movement through different regions (>200-fold difference in Bronsted acidities). By contrast, at low flash rates a previously unreported reversal occurs that favors Br- cultures for both proton evolution and less PSII charge recombination. In Br- cultures, slower proton transfer rate is attributed to stronger ion-pairing of Br- with AA residues lining the water channels. Both anions charge-neutralize protons and shepherd them to the lumen using dry aqueous channels.
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Affiliation(s)
- Colin Gates
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, NJ 08854, USA; Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, NJ 08854, USA; Department of Computational Biology and Molecular Biophysics, Rutgers, The State University of New Jersey, NJ 08854, USA; Department of Chemistry and Biochemistry, Loyola University Chicago, IL 60660, USA
| | - Jonah M Williams
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, NJ 08854, USA; Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, NJ 08854, USA
| | - Gennady Ananyev
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, NJ 08854, USA; Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, NJ 08854, USA
| | - G Charles Dismukes
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, NJ 08854, USA; Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, NJ 08854, USA.
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49
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Bhowmick A, Simon PS, Bogacz I, Hussein R, Zhang M, Makita H, Ibrahim M, Chatterjee R, Doyle MD, Cheah MH, Chernev P, Fuller FD, Fransson T, Alonso-Mori R, Brewster AS, Sauter NK, Bergmann U, Dobbek H, Zouni A, Messinger J, Kern J, Yachandra VK, Yano J. Going around the Kok cycle of the water oxidation reaction with femtosecond X-ray crystallography. IUCRJ 2023; 10:642-655. [PMID: 37870936 PMCID: PMC10619448 DOI: 10.1107/s2052252523008928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 10/11/2023] [Indexed: 10/25/2023]
Abstract
The water oxidation reaction in photosystem II (PS II) produces most of the molecular oxygen in the atmosphere, which sustains life on Earth, and in this process releases four electrons and four protons that drive the downstream process of CO2 fixation in the photosynthetic apparatus. The catalytic center of PS II is an oxygen-bridged Mn4Ca complex (Mn4CaO5) which is progressively oxidized upon the absorption of light by the chlorophyll of the PS II reaction center, and the accumulation of four oxidative equivalents in the catalytic center results in the oxidation of two waters to dioxygen in the last step. The recent emergence of X-ray free-electron lasers (XFELs) with intense femtosecond X-ray pulses has opened up opportunities to visualize this reaction in PS II as it proceeds through the catalytic cycle. In this review, we summarize our recent studies of the catalytic reaction in PS II by following the structural changes along the reaction pathway via room-temperature X-ray crystallography using XFELs. The evolution of the electron density changes at the Mn complex reveals notable structural changes, including the insertion of OX from a new water molecule, which disappears on completion of the reaction, implicating it in the O-O bond formation reaction. We were also able to follow the structural dynamics of the protein coordinating with the catalytic complex and of channels within the protein that are important for substrate and product transport, revealing well orchestrated conformational changes in response to the electronic changes at the Mn4Ca cluster.
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Affiliation(s)
- Asmit Bhowmick
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Philipp S. Simon
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Isabel Bogacz
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Rana Hussein
- Department of Biology, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Miao Zhang
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Hiroki Makita
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Mohamed Ibrahim
- Department of Biology, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Ruchira Chatterjee
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Margaret D. Doyle
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Mun Hon Cheah
- Molecular Biomimetics, Department of Chemistry- Ångström, Uppsala University, Uppsala SE 75120, Sweden
| | - Petko Chernev
- Molecular Biomimetics, Department of Chemistry- Ångström, Uppsala University, Uppsala SE 75120, Sweden
| | - Franklin D. Fuller
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Thomas Fransson
- Department of Physics, AlbaNova University Center, Stockholm University, Stockholm SE-10691, Sweden
| | - Roberto Alonso-Mori
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Aaron S. Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Nicholas K. Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Uwe Bergmann
- Department of Physics, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Holger Dobbek
- Department of Biology, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Athina Zouni
- Department of Biology, Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Johannes Messinger
- Molecular Biomimetics, Department of Chemistry- Ångström, Uppsala University, Uppsala SE 75120, Sweden
- Department of Chemistry, Umeå University, Umeå SE 90187, Sweden
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Vittal K. Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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50
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Hussein R, Ibrahim M, Bhowmick A, Simon PS, Bogacz I, Doyle MD, Dobbek H, Zouni A, Messinger J, Yachandra VK, Kern JF, Yano J. Evolutionary diversity of proton and water channels on the oxidizing side of photosystem II and their relevance to function. PHOTOSYNTHESIS RESEARCH 2023; 158:91-107. [PMID: 37266800 PMCID: PMC10684718 DOI: 10.1007/s11120-023-01018-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/29/2023] [Indexed: 06/03/2023]
Abstract
One of the reasons for the high efficiency and selectivity of biological catalysts arise from their ability to control the pathways of substrates and products using protein channels, and by modulating the transport in the channels using the interaction with the protein residues and the water/hydrogen-bonding network. This process is clearly demonstrated in Photosystem II (PS II), where its light-driven water oxidation reaction catalyzed by the Mn4CaO5 cluster occurs deep inside the protein complex and thus requires the transport of two water molecules to and four protons from the metal center to the bulk water. Based on the recent advances in structural studies of PS II from X-ray crystallography and cryo-electron microscopy, in this review we compare the channels that have been proposed to facilitate this mass transport in cyanobacteria, red and green algae, diatoms, and higher plants. The three major channels (O1, O4, and Cl1 channels) are present in all species investigated; however, some differences exist in the reported structures that arise from the different composition and arrangement of membrane extrinsic subunits between the species. Among the three channels, the Cl1 channel, including the proton gate, is the most conserved among all photosynthetic species. We also found at least one branch for the O1 channel in all organisms, extending all the way from Ca/O1 via the 'water wheel' to the lumen. However, the extending path after the water wheel varies between most species. The O4 channel is, like the Cl1 channel, highly conserved among all species while having different orientations at the end of the path near the bulk. The comparison suggests that the previously proposed functionality of the channels in T. vestitus (Ibrahim et al., Proc Natl Acad Sci USA 117:12624-12635, 2020; Hussein et al., Nat Commun 12:6531, 2021) is conserved through the species, i.e. the O1-like channel is used for substrate water intake, and the tighter Cl1 and O4 channels for proton release. The comparison does not eliminate the potential role of O4 channel as a water intake channel. However, the highly ordered hydrogen-bonded water wire connected to the Mn4CaO5 cluster via the O4 may strongly suggest that it functions in proton release, especially during the S0 → S1 transition (Saito et al., Nat Commun 6:8488, 2015; Kern et al., Nature 563:421-425, 2018; Ibrahim et al., Proc Natl Acad Sci USA 117:12624-12635, 2020; Sakashita et al., Phys Chem Chem Phys 22:15831-15841, 2020; Hussein et al., Nat Commun 12:6531, 2021).
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Affiliation(s)
- Rana Hussein
- Department of Biology, Humboldt-Universität Zu Berlin, 10099, Berlin, Germany.
| | - Mohamed Ibrahim
- Department of Biology, Humboldt-Universität Zu Berlin, 10099, Berlin, Germany
| | - Asmit Bhowmick
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Philipp S Simon
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Isabel Bogacz
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Margaret D Doyle
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Holger Dobbek
- Department of Biology, Humboldt-Universität Zu Berlin, 10099, Berlin, Germany
| | - Athina Zouni
- Department of Biology, Humboldt-Universität Zu Berlin, 10099, Berlin, Germany
| | - Johannes Messinger
- Molecular Biomimetics, Department of Chemistry-Ångström, Uppsala University, SE 75120, Uppsala, Sweden
- Department of Chemistry, Umeå University, SE 90187, Umeå, Sweden
| | - Vittal K Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jan F Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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