1
|
Wang J. Composition Heterogeneity of Metal Ions Bound at the Oxygen-Evolving Center of Photosystem II in Living Cells. Biochemistry 2024; 63:1963-1968. [PMID: 39037205 DOI: 10.1021/acs.biochem.4c00261] [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: 07/23/2024]
Abstract
Recent resolution advancement of in situ cryo-electron tomography (cryo-ET) and cryo-electron microscopy (cryo-EM) enables us to visualize large enzymes-in-action in atomic detail in their native environments inside living cells, such as photosystem II (PSII) and the ribosome. A variety of crystallographic and cryo-EM structures of PSII have been published for the purified PSII dimeric core complexes by itself, in supercomplexes with photosystem I (PSI) and light-harvesting complexes (LHC), and in megacomplexes with phycobilisome (PBS). In the latter case, two or five copies of asymmetric dimeric PSII molecules are present in highly asymmetric environments that differ from other 2-fold symmetric structures. Previous systematic analysis of X-ray free-electron laser (XFEL) crystal structures of PSII has shown different degrees of composition heterogeneity of metal ion cofactor bound at the oxygen-evolving center (OEC), including between two monomers of the same PSII dimer. This study analyzed the metal ions bound at four OECs in two asymmetric dimeric PSII molecules within in situ cryo-ET structures reported for an asymmetric PBS-PSII-PSI-LHC megacomplex determined in a living organism without purification and shows that composition heterogeneity with reduced metal ion occupancies at the OEC of PSII is a general phenomenon. This finding could have profound implications for spectroscopic interpretations of unpurified PSII samples.
Collapse
Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, United States
| |
Collapse
|
2
|
Drosou M, Comas-Vilà G, Neese F, Salvador P, Pantazis DA. Does Serial Femtosecond Crystallography Depict State-Specific Catalytic Intermediates of the Oxygen-Evolving Complex? J Am Chem Soc 2023; 145:10604-10621. [PMID: 37137865 DOI: 10.1021/jacs.3c00489] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Recent advances in serial femtosecond crystallography (SFX) of photosystem II (PSII), enabled by X-ray free electron lasers (XFEL), provided the first geometric models of distinct intermediates in the catalytic S-state cycle of the oxygen-evolving complex (OEC). These models are obtained by flash-advancing the OEC from the dark-stable state (S1) to more oxidized intermediates (S2 and S3), eventually cycling back to the most reduced S0. However, the interpretation of these models is controversial because geometric parameters within the Mn4CaO5 cluster of the OEC do not exactly match those expected from coordination chemistry for the spectroscopically verified manganese oxidation states of the distinct S-state intermediates. Here we focus on the first catalytic transition, S1 → S2, which represents a one-electron oxidation of the OEC. Combining geometric and electronic structure criteria, including a novel effective oxidation state approach, we analyze existing 1-flash (1F) SFX-XFEL crystallographic models that should depict the S2 state of the OEC. We show that the 1F/S2 equivalence is not obvious, because the Mn oxidation states and total unpaired electron counts encoded in these models are not fully consistent with those of a pure S2 state and with the nature of the S1 → S2 transition. Furthermore, the oxidation state definition in two-flashed (2F) structural models is practically impossible to elucidate. Our results advise caution in the extraction of electronic structure information solely from the literal interpretation of crystallographic models and call for re-evaluation of structural and mechanistic interpretations that presume exact correspondence of such models to specific catalytic intermediates of the OEC.
Collapse
Affiliation(s)
- Maria Drosou
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Gerard Comas-Vilà
- Institute of Computational Chemistry and Catalysis, Chemistry Department, University of Girona, Montilivi Campus, Girona, Catalonia 17003, Spain
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Pedro Salvador
- Institute of Computational Chemistry and Catalysis, Chemistry Department, University of Girona, Montilivi Campus, Girona, Catalonia 17003, Spain
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| |
Collapse
|
3
|
Bigness A, Vaddypally S, Zdilla MJ, Mendoza-Cortes JL. Ubiquity of cubanes in bioinorganic relevant compounds. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
4
|
Baituti B, Odisitse S. A Computational Study of the S 2 State in the Oxygen-Evolving Complex of Photosystem II by Electron Paramagnetic Resonance Spectroscopy. Molecules 2021; 26:2699. [PMID: 34064533 PMCID: PMC8125536 DOI: 10.3390/molecules26092699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/22/2021] [Accepted: 04/24/2021] [Indexed: 11/16/2022] Open
Abstract
The S2 state produces two basic electron paramagnetic resonance signal types due to the manganese cluster in oxygen-evolving complex, which are influenced by the solvents, and cryoprotectant added to the photosystem II samples. It is presumed that a single manganese center oxidation occurs on S1 → S2 state transition. The S2 state has readily visible multiline and g4.1 electron paramagnetic resonance signals and hence it has been the most studied of all the Kok cycle intermediates due to the ease of experimental preparation and stability. The S2 state was studied using electron paramagnetic resonance spectroscopy at X-band frequencies. The aim of this study was to determine the spin states of the g4.1 signal. The multiline signal was observed to arise from a ground state spin ½ centre while the g4.1 signal generated at ≈140 K NIR illumination was proposed to arise from a spin 52 center with rhombic distortion. The 'ground' state g4.1 signal was generated solely or by conversion from the multiline. The data analysis methods used involved numerical simulations of the experimental spectra on relevant models of the oxygen-evolving complex cluster. A strong focus in this paper was on the 'ground' state g4.1 signal, whether it is a rhombic 52 spin state signal or an axial 32 spin state signal. The data supported an X-band CW-EPR-generated g4.1 signal as originating from a near rhombic spin 5/2 of the S2 state of the PSII manganese cluster.
Collapse
Affiliation(s)
- Bernard Baituti
- Department of Chemical and Forensic Science, Faculty of Science, Botswana International University of Science and Technology, Private Bag 16, Palapye, Botswana;
| | | |
Collapse
|
5
|
Sato A, Nakano Y, Nakamura S, Noguchi T. Rapid-Scan Time-Resolved ATR-FTIR Study on the Photoassembly of the Water-Oxidizing Mn4CaO5 Cluster in Photosystem II. J Phys Chem B 2021; 125:4031-4045. [DOI: 10.1021/acs.jpcb.1c01624] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Akihiko Sato
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Yuki Nakano
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Shin Nakamura
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Takumi Noguchi
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| |
Collapse
|
6
|
Evaluation of new low-valent computational models for the oxygen-evolving complex of photosystem II. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137629] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
7
|
Abstract
The oxygen-evolving center (OEC) in photosystem II (PSII) of plants, algae and cyanobacteria is a unique natural catalyst that splits water into electrons, protons and dioxygen. The crystallographic studies of PSII have revealed that the OEC is an asymmetric Mn4CaO5-cluster. The understanding of the structure-function relationship of this natural Mn4CaO5-cluster is impeded mainly due to the complexity of the protein environment and lack of a rational chemical model as a reference. Although it has been a great challenge for chemists to synthesize the OEC in the laboratory, significant advances have been achieved recently. Different artificial complexes have been reported, especially a series of artificial Mn4CaO4-clusters that closely mimic both the geometric and electronic structures of the OEC in PSII, which provides a structurally well-defined chemical model to investigate the structure-function relationship of the natural Mn4CaO5-cluster. The deep investigations on this artificial Mn4CaO4-cluster could provide new insights into the mechanism of the water-splitting reaction in natural photosynthesis and may help the development of efficient catalysts for the water-splitting reaction in artificial photosynthesis.
Collapse
|
8
|
Yamamoto M, Nakamura S, Noguchi T. Protonation structure of the photosynthetic water oxidizing complex in the S0 state as revealed by normal mode analysis using quantum mechanics/molecular mechanics calculations. Phys Chem Chem Phys 2020; 22:24213-24225. [DOI: 10.1039/d0cp04079g] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Protonation structure of the first intermediate of the water oxidizing complex was determined by QM/MM calculations of molecular vibrations.
Collapse
Affiliation(s)
- Masao Yamamoto
- Division of Material Science
- Graduate School of Science
- Nagoya University
- Nagoya
- Japan
| | - Shin Nakamura
- Division of Material Science
- Graduate School of Science
- Nagoya University
- Nagoya
- Japan
| | - Takumi Noguchi
- Division of Material Science
- Graduate School of Science
- Nagoya University
- Nagoya
- Japan
| |
Collapse
|
9
|
Assessment of the manganese cluster's oxidation state via photoactivation of photosystem II microcrystals. Proc Natl Acad Sci U S A 2019; 117:141-145. [PMID: 31848244 DOI: 10.1073/pnas.1915879117] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Knowledge of the manganese oxidation states of the oxygen-evolving Mn4CaO5 cluster in photosystem II (PSII) is crucial toward understanding the mechanism of biological water oxidation. There is a 4 decade long debate on this topic that historically originates from the observation of a multiline electron paramagnetic resonance (EPR) signal with effective total spin of S = 1/2 in the singly oxidized S2 state of this cluster. This signal implies an overall oxidation state of either Mn(III)3Mn(IV) or Mn(III)Mn(IV)3 for the S2 state. These 2 competing assignments are commonly known as "low oxidation (LO)" and "high oxidation (HO)" models of the Mn4CaO5 cluster. Recent advanced EPR and Mn K-edge X-ray spectroscopy studies converge upon the HO model. However, doubts about these assignments have been voiced, fueled especially by studies counting the number of flash-driven electron removals required for the assembly of an active Mn4CaO5 cluster starting from Mn(II) and Mn-free PSII. This process, known as photoactivation, appeared to support the LO model since the first oxygen is reported to evolve already after 7 flashes. In this study, we improved the quantum yield and sensitivity of the photoactivation experiment by employing PSII microcrystals that retained all protein subunits after complete manganese removal and by oxygen detection via a custom built thin-layer cell connected to a membrane inlet mass spectrometer. We demonstrate that 9 flashes by a nanosecond laser are required for the production of the first oxygen, which proves that the HO model provides the correct description of the Mn4CaO5 cluster's oxidation states.
Collapse
|
10
|
Chen H, Case DA, Dismukes GC. Reconciling Structural and Spectroscopic Fingerprints of the Oxygen-Evolving Complex of Photosystem II: A Computational Study of the S 2 State. J Phys Chem B 2018; 122:11868-11882. [PMID: 30444623 DOI: 10.1021/acs.jpcb.8b08147] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The catalytic cycle of photosynthetic water oxidation occurs at the Mn4CaO5 oxygen-evolving complex (OEC) of photosystem II. Extensive spectroscopic data have been collected on the intermediates, especially the S2 (Kok) state, although the proton and electron inventories (Mn oxidation states) are still uncertain. The "high oxidation" paradigm assigns S2 Mn oxidation level (III, IV, IV, IV) or (IV, IV, IV, III), whereas a "low oxidation" paradigm posits two additional electrons. Here, we investigate the geometric (X-ray diffraction, extended X-ray absorption fine structure) and spectroscopic (electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR)) properties of the S2 state using quantum chemical density functional theory calculations, focusing on the neglected low paradigm. Two interconvertible electronic spin configurations are predicted as ground states, producing multiline ( S = 1/2) and broad ( S = 5/2) EPR signals in the low paradigm oxidation state (III, IV, III, III) and with W2 as OH- and O5 as OH-. They have "open" ( S = 5/2) and "closed" ( S = 1/2) Mn3CaO4-cubane geometries. Other energetically accessible isomers with ground spin states 1/2, 7/2, 9/2, or 11/2 can be obtained through perturbations of hydrogen-bonding networks (e.g., H+ from His337 to O3 or W2), consistent with experimental observations. Conformers with the low oxidation state configuration (III, IV, IV, II) also become energetically accessible when the protonation states are O5 (OH-), W2 (H2O), and neutral His337. The configuration with (III, IV, III, III) agrees well with earlier low-temperature EPR and ENDOR interpretations, whereas the MnII-containing configuration agrees partially with recent ENDOR data. However, the low oxidation paradigm does not yield isotropic ligand hyperfine interactions in good agreement with observed values. We conclude that the low Mn oxidation state proposal for the OEC can closely fit most of the available structural and electronic data for S2 at accessible energies.
Collapse
|
11
|
Petrie S, Stranger R, Pace RJ. Explaining the Different Geometries of the Water Oxidising Complex in the Nominal S 3 State Crystal Structures of Photosystem II at 2.25 Å and 2.35 Å. Chemphyschem 2018; 19:3296-3309. [PMID: 30290080 DOI: 10.1002/cphc.201800686] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Indexed: 11/10/2022]
Abstract
Recently two atomic resolution crystal structures of Photosystem II, in the double flashed, nominal S3 intermediate state of its Mn4 Ca water oxidising complex (WOC), have been presented (Young et al., Nature 2016, 540, 453; Suga et al., Nature 2017, 543, 131). These structures are at 2.25 Å and 2.35 Å resolution, respectively. Although highly similar in most respects, the structures differ in a key region within the WOC catalytic site. In the 2.25 Å structure, one oxy species (O5) is observed within the WOC cavity, weakly associated with the Mn centres, similar to that seen earlier in the 1.95 Å XRD structure of the S1 intermediate (Suga et al., Nature, 2015, 517, 99). In the 2.35 Å structure, two such species are seen (O5, O6), with the Mn centres and O5 positioned as in the 2.25 Å structure and an O5-O6 separation of ∼1.5 Å, consistent with peroxo formation. This suggests O5 and O6 are substrate water derived species in this double flashed form. Recently we have presented (Petrie, et al., Chem. Phys. Chem., 2017) a large scale (220 atom) quantum chemical model of the Young et al. 2.25 Å structure, which quantitatively explains all significant features within the WOC region of that structure, particularly the positions of the metal centres and O5 group. Critical to this was our assumption of a 'low' Mn oxidation paradigm (mean S1 Mn oxidation level of +3.0, Petrie et al., Angew. Chem. Int. Ed., 2015), rather than a 'high' oxidation model (mean S1 oxidation level of +3.5), widely assumed in the literature. Here we show that our same oxidation state model predicts two classes of energetically close S3 structural forms, analogous to the S1 state, one with the metal centres and O5 positioned as in the 2.25 Å structure, and the other with the metals similarly placed, but with O5 located in the O6 position of the 2.35 Å structure. We show that the Suga et al. 2.35 Å structure is likely a superposition of two such forms, one from each class, which is consistent with reported atomic occupancies for that structure and the relative total energies we calculate for the two structural forms.
Collapse
Affiliation(s)
- Simon Petrie
- Research School of Chemistry, College of Physical and Mathematical Sciences, The Australian National University, Acton ACT, Australia, 2601
| | - Robert Stranger
- Research School of Chemistry, College of Physical and Mathematical Sciences, The Australian National University, Acton ACT, Australia, 2601
| | - Ron J Pace
- Research School of Chemistry, College of Physical and Mathematical Sciences, The Australian National University, Acton ACT, Australia, 2601
| |
Collapse
|
12
|
Baituti B. Computational studies of the Mn 4/Ca cluster in photosystem II. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2018. [DOI: 10.1142/s0219633618500074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Computational chemistry with the data from more detailed X-ray diffraction (XRD) oxygen evolving complex (OEC) structure has been used extensively of late in exploring the mechanisms of water oxidation in the OEC. The study reported in this paper involves density functional theory (DFT) calculations to investigate whether the data are in agreement with the four manganese ions in the OEC, being organized as a ‘3[Formula: see text]1’ (trimer plus one) model [Gatt et al. Angewandte Chemie International Edition, 51, 12025–12028, 2012; Petrie et al. Chemistry - A European Journal, 21, 6780–6792, 2015; Terrett et al. Chemical Communications, 50, 3187–3190, 2014] or ‘dimer of dimers’ model. [Terrett et al. Journal of Inorganic Biochemistry, 162, 178–189, 2016]. The data analysis method used involves quantum chemical DFT calculations on relevant models of the OEC cluster. DFT calculations were performed using both the so-called ‘open’ and ‘closed’ forms [Terrett et al. Journal of Inorganic Biochemistry, 162, 178–189, 2016] of the S2 OEC structure models with total spin ([Formula: see text]) 1/2, 7/2, 9/2 and 15/2 within the MnIII MnIV MnIII MnIII ‘low’ oxidation paradigm to examine exchange coupling within the OEC cluster. The results show that the [Formula: see text]-coupling in the ‘closed’ form: [Formula: see text][Formula: see text]cm[Formula: see text], [Formula: see text][Formula: see text]cm[Formula: see text], [Formula: see text][Formula: see text]cm[Formula: see text] and [Formula: see text]–[Formula: see text][Formula: see text]cm[Formula: see text]. In the ‘closed’ form, [Formula: see text] and [Formula: see text] represent the two largest exchange interactions within the manganese cluster, whereas [Formula: see text] and [Formula: see text] are small and almost net cancel. The magnetic coupling between the four Mn ions is close to ‘dimer of dimers’, with both dimers anti-ferromagnetically coupled internally and with weak inter-dimer net coupling.
Collapse
Affiliation(s)
- Bernard Baituti
- Botswana International University of Science and Technology, Private Bag 16, Palapye, Botswana
| |
Collapse
|
13
|
Beal NJ, Corry TA, O’Malley PJ. Comparison between Experimental and Broken Symmetry Density Functional Theory (BS-DFT) Calculated Electron Paramagnetic Resonance (EPR) Parameters of the S2 State of the Oxygen-Evolving Complex of Photosystem II in Its Native (Calcium) and Strontium-Substituted Form. J Phys Chem B 2017; 121:11273-11283. [DOI: 10.1021/acs.jpcb.7b09498] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Nathan J. Beal
- School of Chemistry, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Thomas A. Corry
- School of Chemistry, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Patrick J. O’Malley
- School of Chemistry, The University of Manchester, Manchester M13 9PL, United Kingdom
| |
Collapse
|
14
|
Retegan M, Pantazis DA. Differences in the Active Site of Water Oxidation among Photosynthetic Organisms. J Am Chem Soc 2017; 139:14340-14343. [PMID: 28948784 DOI: 10.1021/jacs.7b06351] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The site of biological water oxidation is highly conserved across photosynthetic organisms, but differences of unidentified structural and electronic origin exist between taxonomically discrete clades, revealed by distinct spectroscopic signatures of the oxygen-evolving Mn4CaO5 cluster and variations in active-site accessibility. Comparison of atomistic models of a native cyanobacterial form (Thermosynechococcus vulcanus) and a chimeric spinach-like form of photosystem II allows us to identify the precise atomic-level differences between organisms in the vicinity of the manganese cluster. Substitution of cyanobacterial D1-Asn87 by higher-plant D1-Ala87 is the principal discriminating feature: it drastically rearranges a network of proximal hydrogen bonds, modifying the local architecture of a water channel and the interaction of second coordination shell residues with the manganese cluster. The two variants explain species-dependent differences in spectroscopic properties and in the interaction of substrate analogues with the oxygen-evolving complex, enabling assignment of a substrate delivery channel to the active site.
Collapse
Affiliation(s)
- Marius Retegan
- European Synchrotron Radiation Facility , 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Dimitrios A Pantazis
- Max Planck Institute for Chemical Energy Conversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| |
Collapse
|
15
|
Najafpour MM, Heidari S, Balaghi SE, Hołyńska M, Sadr MH, Soltani B, Khatamian M, Larkum AW, Allakhverdiev SI. Proposed mechanisms for water oxidation by Photosystem II and nanosized manganese oxides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:156-174. [DOI: 10.1016/j.bbabio.2016.11.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/05/2016] [Accepted: 11/08/2016] [Indexed: 12/18/2022]
|
16
|
Gerey B, Gouré E, Fortage J, Pécaut J, Collomb MN. Manganese-calcium/strontium heterometallic compounds and their relevance for the oxygen-evolving center of photosystem II. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2016.04.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
17
|
Terrett R, Petrie S, Stranger R, Pace RJ. What computational chemistry and magnetic resonance reveal concerning the oxygen evolving centre in Photosystem II. J Inorg Biochem 2016; 162:178-189. [PMID: 27157978 DOI: 10.1016/j.jinorgbio.2016.04.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/01/2016] [Accepted: 04/04/2016] [Indexed: 11/18/2022]
Abstract
Density Functional Theory (DFT) computational studies of the Mn4/Ca Oxygen Evolving Complex (OEC) region of Photosystem II in the paramagnetic S2 and S3 states of the water oxdizing catalytic cycle are described. These build upon recent advances in computationally understanding the detailed S1 state OEC geometries, revealed by the recent high resolution Photosystem II crystal structures of Shen et al., at 1.90Å and 1.95Å (Petrie et al., 2015, Angew. Chem. Int. Ed., 54, 7120). The models feature a 'Low Oxidation Paradigm' assumption for the mean Mn oxidation states in the functional enzyme, with the mean oxidation levels being 3.0, 3.25 and 3.5 in S1, S2 and S3, respectively. These calculations are used to infer magnetic exchange interactions within the coupled OEC cluster, particularly in the Electron Paramagnetic Resonance (EPR)-visible S2 and S3 states. Detailed computational estimates of the intrinsic magnitudes and molecular orientations of the 55Mn hyperfine tensors in the S2 state are presented. These parameters, together with the resultant spin projected hyperfine values are compared with recent appropriate experimental EPR data (Continuous Wave (CW), Electron-Nuclear Double Resonance (ENDOR) and ELDOR (Electron-Electron Double Resonance)-Detected Nuclear Magnetic Resonance (EDNMR)) from the OEC. It is found that an effective Coupled Dimer magnetic organization of the four Mn in the OEC cluster in the S2 and S3 states is able to quantitatively rationalize the observed 55Mn hyperfine data. This is consistent with structures we propose to represent the likely state of the OEC in the catalytically active form of the enzyme.
Collapse
Affiliation(s)
- Richard Terrett
- Research School of Chemistry, College of Physical and Mathematical Sciences, Australian National University, Canberra, ACT 0200, Australia
| | - Simon Petrie
- Research School of Chemistry, College of Physical and Mathematical Sciences, Australian National University, Canberra, ACT 0200, Australia
| | - Rob Stranger
- Research School of Chemistry, College of Physical and Mathematical Sciences, Australian National University, Canberra, ACT 0200, Australia
| | - Ron J Pace
- Research School of Chemistry, College of Physical and Mathematical Sciences, Australian National University, Canberra, ACT 0200, Australia.
| |
Collapse
|
18
|
Chuah WY, Stranger R, Pace RJ, Krausz E, Frankcombe TJ. Deprotonation of Water/Hydroxo Ligands in Clusters Mimicking the Water Oxidizing Complex of PSII and Its Effect on the Vibrational Frequencies of Ligated Carboxylate Groups. J Phys Chem B 2016; 120:377-85. [PMID: 26727127 DOI: 10.1021/acs.jpcb.5b09987] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The IR absorptions of several first-shell carboxylate ligands of the water oxidizing complex (WOC) have been experimentally shown to be unaffected by oxidation state changes in the WOC during its catalytic cycle. Several model clusters that mimic the Mn4O5Ca core of the WOC in the S1 state, with electronic configurations that correspond to both the so-called "high" and "low" oxidation paradigms, were investigated. Deprotonation at W2, W1, or O3 sites was found to strongly reduce carboxylate ligand frequency shifts on oxidation of the metal cluster. The frequency shifts were smallest in neutrally charged clusters where the initial mean Mn oxidation state was +3, with W2 as an hydroxide and O5 a water. Deprotonation also reduced and balanced the oxidation energy of all clusters in successive oxidations.
Collapse
Affiliation(s)
- Wooi Yee Chuah
- Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia
| | - Rob Stranger
- Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia
| | - Ron J Pace
- Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia
| | - Elmars Krausz
- Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia
| | - Terry J Frankcombe
- Research School of Chemistry, Australian National University , Canberra, Australian Capital Territory 2601, Australia.,School of Physical, Environmental and Mathematical Sciences, University of New South Wales , Canberra, Australian Capital Territory 2600, Australia
| |
Collapse
|
19
|
Rizzato R, Bennati M. Cross-Polarization Electron-Nuclear Double Resonance Spectroscopy. Chemphyschem 2015; 16:3769-73. [DOI: 10.1002/cphc.201500938] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Indexed: 01/03/2023]
Affiliation(s)
- Roberto Rizzato
- Research Group EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11; 37077 Göttingen Germany
| | - Marina Bennati
- Research Group EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11; 37077 Göttingen Germany
- Department of Chemistry; University of Göttingen; 37077 Göttingen Germany
| |
Collapse
|
20
|
Nagashima H, Nakajima Y, Shen JR, Mino H. Proton Matrix ENDOR Studies on Ca2+-depleted and Sr2+-substituted Manganese Cluster in Photosystem II. J Biol Chem 2015; 290:28166-28174. [PMID: 26438823 DOI: 10.1074/jbc.m115.675496] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Indexed: 01/08/2023] Open
Abstract
Proton matrix ENDOR spectra were measured for Ca(2+)-depleted and Sr(2+)-substituted photosystem II (PSII) membrane samples from spinach and core complexes from Thermosynechococcus vulcanus in the S2 state. The ENDOR spectra obtained were similar for untreated PSII from T. vulcanus and spinach, as well as for Ca(2+)-containing and Sr(2+)-substituted PSII, indicating that the proton arrangements around the manganese cluster in cyanobacterial and higher plant PSII and Ca(2+)-containing and Sr(2+)-substituted PSII are similar in the S2 state, in agreement with the similarity of the crystal structure of both Ca(2+)-containing and Sr(2+)-substituted PSII in the S1 state. Nevertheless, slightly different hyperfine separations were found between Ca(2+)-containing and Sr(2+)-substituted PSII because of modifications of the water protons ligating to the Sr(2+) ion. Importantly, Ca(2+) depletion caused the loss of ENDOR signals with a 1.36-MHz separation because of the loss of the water proton W4 connecting Ca(2+) and YZ directly. With respect to the crystal structure and the functions of Ca(2+) in oxygen evolution, it was concluded that the roles of Ca(2+) and Sr(2+) involve the maintenance of the hydrogen bond network near the Ca(2+) site and electron transfer pathway to the manganese cluster.
Collapse
Affiliation(s)
- Hiroki Nagashima
- Graduate School of Science, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8602, Japan
| | - Yoshiki Nakajima
- Photosynthesis Research Center, Graduate School of Natural Science and Technology/Faculty of Science, Okayama University, Okayama 700-8530, Japan
| | - Jian-Ren Shen
- Photosynthesis Research Center, Graduate School of Natural Science and Technology/Faculty of Science, Okayama University, Okayama 700-8530, Japan
| | - Hiroyuki Mino
- Graduate School of Science, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8602, Japan.
| |
Collapse
|
21
|
Krewald V, Neese F, Pantazis DA. Resolving the Manganese Oxidation States in the Oxygen-evolving Catalyst of Natural Photosynthesis. Isr J Chem 2015. [DOI: 10.1002/ijch.201500051] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
22
|
Petrie S, Pace RJ, Stranger R. Resolving the Differences Between the 1.9 Å and 1.95 Å Crystal Structures of Photosystem II: A Single Proton Relocation Defines Two Tautomeric Forms of the Water-Oxidizing Complex. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502463] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
23
|
Petrie S, Pace RJ, Stranger R. Resolving the Differences Between the 1.9 Å and 1.95 Å Crystal Structures of Photosystem II: A Single Proton Relocation Defines Two Tautomeric Forms of the Water-Oxidizing Complex. Angew Chem Int Ed Engl 2015; 54:7120-4. [PMID: 25917648 DOI: 10.1002/anie.201502463] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Indexed: 11/11/2022]
Abstract
Great progress has been made in characterizing the water-oxidizing complex (WOC) in photosystem II (PSII) with the publication of a 1.9 Å resolution X-ray diffraction (XRD) and recently a 1.95 Å X-ray free-electron laser (XFEL) structure. However, these achievements are under threat because of perceived conflicts with other experimental data. For the earlier 1.9 Å structure, lack of agreement with extended X-ray absorption fine structure (EXAFS) data led to the notion that the WOC suffered from X-ray photoreduction. In the recent 1.95 Å structure, Mn photoreduction is not an issue, but poor agreement with computational models which adopt the 'high' oxidation state paradigm, has again resulted in criticism of the structure on the basis of contamination with lower S states of the WOC. Here we use DFT modeling to show that the distinct WOC geometries in the 1.9 and 1.95 Å structures can be straightforwardly accounted for when the Mn oxidation states are consistent with the 'low' oxidation state paradigm. Remarkably, our calculations show that the two structures are tautomers, related by a single proton relocation.
Collapse
Affiliation(s)
- Simon Petrie
- Research School of Chemistry, Australian National University, Canberra ACT 0200 (Australia)
| | - Ron J Pace
- Research School of Chemistry, Australian National University, Canberra ACT 0200 (Australia).
| | - Rob Stranger
- Research School of Chemistry, Australian National University, Canberra ACT 0200 (Australia).
| |
Collapse
|
24
|
Petrie S, Stranger R, Pace RJ. Rationalising the Geometric Variation between the A and B Monomers in the 1.9 Å Crystal Structure of Photosystem II. Chemistry 2015; 21:6780-92. [DOI: 10.1002/chem.201406419] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Indexed: 11/12/2022]
|
25
|
Krewald V, Retegan M, Cox N, Messinger J, Lubitz W, DeBeer S, Neese F, Pantazis DA. Metal oxidation states in biological water splitting. Chem Sci 2015; 6:1676-1695. [PMID: 29308133 PMCID: PMC5639794 DOI: 10.1039/c4sc03720k] [Citation(s) in RCA: 230] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 12/31/2014] [Indexed: 12/20/2022] Open
Abstract
A central question in biological water splitting concerns the oxidation states of the manganese ions that comprise the oxygen-evolving complex of photosystem II.
A central question in biological water splitting concerns the oxidation states of the manganese ions that comprise the oxygen-evolving complex of photosystem II. Understanding the nature and order of oxidation events that occur during the catalytic cycle of five Si states (i = 0–4) is of fundamental importance both for the natural system and for artificial water oxidation catalysts. Despite the widespread adoption of the so-called “high-valent scheme”—where, for example, the Mn oxidation states in the S2 state are assigned as III, IV, IV, IV—the competing “low-valent scheme” that differs by a total of two metal unpaired electrons (i.e. III, III, III, IV in the S2 state) is favored by several recent studies for the biological catalyst. The question of the correct oxidation state assignment is addressed here by a detailed computational comparison of the two schemes using a common structural platform and theoretical approach. Models based on crystallographic constraints were constructed for all conceivable oxidation state assignments in the four (semi)stable S states of the oxygen evolving complex, sampling various protonation levels and patterns to ensure comprehensive coverage. The models are evaluated with respect to their geometric, energetic, electronic, and spectroscopic properties against available experimental EXAFS, XFEL-XRD, EPR, ENDOR and Mn K pre-edge XANES data. New 2.5 K 55Mn ENDOR data of the S2 state are also reported. Our results conclusively show that the entire S state phenomenology can only be accommodated within the high-valent scheme by adopting a single motif and protonation pattern that progresses smoothly from S0 (III, III, III, IV) to S3 (IV, IV, IV, IV), satisfying all experimental constraints and reproducing all observables. By contrast, it was impossible to construct a consistent cycle based on the low-valent scheme for all S states. Instead, the low-valent models developed here may provide new insight into the over-reduced S states and the states involved in the assembly of the catalytically active water oxidizing cluster.
Collapse
Affiliation(s)
- Vera Krewald
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Marius Retegan
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Nicholas Cox
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Johannes Messinger
- Department of Chemistry , Chemical Biological Center (KBC) , Umeå University , 90187 Umeå , Sweden
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| | - Dimitrios A Pantazis
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-38 , 45470 Mülheim an der Ruhr , Germany .
| |
Collapse
|