1
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Boussac A, Rutherford AW, Sugiura M. Electron transfer pathways from the S2-states to the S3-states either after a Ca2+/Sr2+ or a Cl-/I- exchange in Photosystem II from Thermosynechococcus elongatus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:576-86. [PMID: 25843552 DOI: 10.1016/j.bbabio.2015.03.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 03/25/2015] [Accepted: 03/29/2015] [Indexed: 01/12/2023]
Abstract
The site for water oxidation in Photosystem II (PSII) goes through five sequential oxidation states (S0 to S4) before O2 is evolved. It consists of a Mn4CaO5-cluster close to a redox-active tyrosine residue (YZ). Cl- is also required for enzyme activity. By using EPR spectroscopy it has been shown that both Ca2+/Sr2+ exchange and Cl-/I- exchange perturb the proportions of centers showing high (S=5/2) and low spin (S=1/2) forms of the S2-state. The S3-state was also found to be heterogeneous with: i) a S=3 form that is detectable by EPR and not sensitive to near-infrared light; and ii) a form that is not EPR visible but in which Mn photochemistry occurs resulting in the formation of a (S2YZ)' split EPR signal upon near-infrared illumination. In Sr/Cl-PSII, the high spin (S=5/2) form of S2 shows a marked heterogeneity with a g=4.3 form generated at low temperature that converts to a relaxed form at g=4.9 at higher temperatures. The high spin g=4.9 form can then progress to the EPR detectable form of S3 at temperatures as low as 180K whereas the low spin (S=1/2) S2-state can only advance to the S3 state at temperatures≥235 K. Both of the two S2 configurations and the two S3 configurations are each shown to be in equilibrium at ≥235 K but not at 198 K. Since both S2 configurations are formed at 198 K, they likely arise from two specific populations of S1. The existence of heterogeneous populations in S1, S2 and S3 states may be related to the structural flexibility associated with the positioning of the oxygen O5 within the cluster highlighted in computational approaches and which has been linked to substrate exchange. These data are discussed in the context of recent in silico studies of the electron transfer pathways between the S2-state(s) and the S3-state(s).
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Affiliation(s)
- Alain Boussac
- I(2)BC, CNRS UMR 9198, CEA Saclay, 91191 Gif-sur-Yvette, France.
| | | | - Miwa Sugiura
- Proteo-Science Research Center, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan; Department of Chemistry, Graduate School of Science and Technology, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan; PRESTO, Japan Science and Technology Agency (JST), 4-1-8, Honcho, Kawaguchi, Saitama 332-0012, Japan
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2
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Davis KM, Pushkar YN. Structure of the Oxygen Evolving Complex of Photosystem II at Room Temperature. J Phys Chem B 2015; 119:3492-8. [PMID: 25621994 DOI: 10.1021/acs.jpcb.5b00452] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katherine M. Davis
- Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, Indiana 47907, United States
| | - Yulia N. Pushkar
- Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, Indiana 47907, United States
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3
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Chakraborty M, Mandal PC, Mukhopadhyay S. Mechanistic studies on the oxidation of thiols by a {Mn4O6}4+ core in aqueous acidic media. Polyhedron 2012. [DOI: 10.1016/j.poly.2012.07.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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4
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Davis KM, Mattern BA, Pacold JI, Zakharova T, Brewe D, Kosheleva I, Henning RW, Graber TJ, Heald SM, Seidler GT, Pushkar Y. Fast Detection Allows Analysis of the Electronic Structure of Metalloprotein by X-ray Emission Spectroscopy at Room Temperature. J Phys Chem Lett 2012; 3:1858-1864. [PMID: 22919444 PMCID: PMC3423219 DOI: 10.1021/jz3006223] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The paradigm of "detection-before-destruction" was tested for a metalloprotein complex exposed at room temperature to the high x-ray flux typical of third generation synchrotron sources. Following the progression of the x-ray induced damage by Mn Kβ x-ray emission spectroscopy, we demonstrated the feasibility of collecting room temperature data on the electronic structure of native Photosystem II, a trans-membrane metalloprotein complex containing a Mn(4)Ca cluster. The determined non-damaging observation timeframe (about 100 milliseconds using continuous monochromatic beam, deposited dose 1*10(7) photons/µm(2) or 1.3*10(4) Gy, and 66 microseconds in pulsed mode using pink beam, deposited dose 4*10(7) photons/µm(2) or 4.2*10(4) Gy) is sufficient for the analysis of this protein's electron dynamics and catalytic mechanism at room temperature. Reported time frames are expected to be representative for other metalloproteins. The described instrumentation, based on the short working distance dispersive spectrometer, and experimental methodology is broadly applicable to time-resolved x-ray emission analysis at synchrotron and x-ray free-electron laser light sources.
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Affiliation(s)
| | - Brian A. Mattern
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | - Joseph I. Pacold
- Department of Physics, University of Washington, Seattle, WA 98195, USA
| | | | - Dale Brewe
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439
| | - Irina Kosheleva
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL 60637, USA
| | - Robert W. Henning
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL 60637, USA
| | - Timothy J. Graber
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL 60637, USA
| | - Steve M. Heald
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439
| | - Gerald T. Seidler
- Department of Physics, University of Washington, Seattle, WA 98195, USA
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5
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Samuel PP, Horn S, Döring A, Havelius KGV, Reschke S, Leimkühler S, Haumann M, Schulzke C. A Crystallographic and Mo K-Edge XAS Study of Molybdenum Oxo Bis-, Mono-, and Non-Dithiolene Complexes - First-Sphere Coordination Geometry and Noninnocence of Ligands. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201100331] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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6
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Grundmeier A, Dau H. Structural models of the manganese complex of photosystem II and mechanistic implications. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:88-105. [PMID: 21787743 DOI: 10.1016/j.bbabio.2011.07.004] [Citation(s) in RCA: 191] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 07/06/2011] [Accepted: 07/08/2011] [Indexed: 11/29/2022]
Abstract
Photosynthetic water oxidation and O₂ formation are catalyzed by a Mn₄Ca complex bound to the proteins of photosystem II (PSII). The catalytic site, including the inorganic Mn₄CaO(n)H(x) core and its protein environment, is denoted as oxygen-evolving complex (OEC). Earlier and recent progress in the endeavor to elucidate the structure of the OEC is reviewed, with focus on recent results obtained by (i) X−ray spectroscopy (specifically by EXAFS analyses), and (ii) X-ray diffraction (XRD, protein crystallography). Very recently, an impressive resolution of 1.9Å has been achieved by XRD. Most likely however, all XRD data on the Mn₄CaO(n)H(x) core of the OEC are affected by X-ray induced modifications (radiation damage). Therefore and to address (important) details of the geometric and electronic structure of the OEC, a combined analysis of XRD and XAS data has been approached by several research groups. These efforts are reviewed and extended using an especially comprehensive approach. Taking into account XRD results on the protein environment of the inorganic core of the Mn complex, 12 alternative OEC models are considered and evaluated by quantitative comparison to (i) extended-range EXAFS data, (ii) polarized EXAFS of partially oriented PSII membrane particles, and (iii) polarized EXAFS of PSII crystals. We conclude that there is a class of OEC models that is in good agreement with both the recent crystallographic models and the XAS data. On these grounds, mechanistic implications for the O−O bond formation chemistry are discussed. This article is part of a Special Issue entitled: Photosystem II.
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7
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Chakraborty M, Singh NJ, Mandal PC, Das S, Mukhopadhyay S. Mechanistic studies on the oxidation of ascorbic acid and hydroquinone by a {Mn4O6}4+ core in aqueous media. J Phys Chem A 2011; 115:4882-93. [PMID: 21517065 DOI: 10.1021/jp202690a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Described in this work is the kinetics of oxidation of ascorbic acid and hydroquinone by a tetranuclear Mn(IV) oxidant, [Mn(4)(μ-O)(6)(bipy)(6)](4+) (1(4+), bipy =2,2(/)-bipyridine), in aqueous solution over a wide pH range 1.5-6.0. In particular, below pH 3.0, protonation on the oxo-bridge of 1(4+) results in the formation of [Mn(4)(μ-O)(5)(μ-OH)(bipy)(6)](5+) (1H(5+)) as an additional oxidant over 1(4+). Both ascorbic acid and ascorbate whereas only hydroquinone and none of its protolytic species were found to be reactive reducing agents in these reactions. Analysis of the rate data clearly established that the oxo-bridge protonated oxidant 1H(5+) is kinetically far more superior to 1(4+) in oxidizing ascorbic acid and hydroquinone. Rates of these reactions are substantially lowered in D(2)O-enriched media in comparison to that in H(2)O media. An initial one electron one proton transfer electroprotic rate step could be mechanistically conceived. DFT studies established that among the two sets of terminal and central Mn(IV) atoms in the tetranuclear oxidant, one of the two terminal Mn(IV) is reduced to Mn(III) at the rate step that we can intuitively predict considering the probable positive charge distribution on the Mn(IV) atoms.
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8
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Havelius KGV, Reschke S, Horn S, Döring A, Niks D, Hille R, Schulzke C, Leimkühler S, Haumann M. Structure of the Molybdenum Site in YedY, a Sulfite Oxidase Homologue from Escherichia coli. Inorg Chem 2010; 50:741-8. [DOI: 10.1021/ic101291j] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kajsa G. V. Havelius
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Stefan Reschke
- Institut für Biochemie und Biologie, Molekulare Enzymologie, Universität Potsdam, Karl-Liebknecht Strasse 24-25, 14476 Potsdam, Germany
| | - Sebastian Horn
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Alexander Döring
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Dimitri Niks
- Department of Biochemistry, University of California, Riverside, California 92521, United States
| | - Russ Hille
- Department of Biochemistry, University of California, Riverside, California 92521, United States
| | - Carola Schulzke
- School of Chemistry, Trinity College, The University of Dublin, Dublin 2, Ireland
| | - Silke Leimkühler
- Institut für Biochemie und Biologie, Molekulare Enzymologie, Universität Potsdam, Karl-Liebknecht Strasse 24-25, 14476 Potsdam, Germany
| | - Michael Haumann
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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9
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Liebisch P, Dau H. Linear Dichroism in the XANES of Partially Oriented Samples: Theory and Application to the Photosynthetic Manganese Complex. Chemphyschem 2010; 11:1236-47. [DOI: 10.1002/cphc.200900954] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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10
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Voevodskaya N, Lendzian F, Sanganas O, Grundmeier A, Gräslund A, Haumann M. Redox Intermediates of the Mn-Fe Site in Subunit R2 of Chlamydia trachomatis Ribonucleotide Reductase. J Biol Chem 2009; 284:4555-66. [DOI: 10.1074/jbc.m807190200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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11
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Photosynthetic water oxidation at elevated dioxygen partial pressure monitored by time-resolved X-ray absorption measurements. Proc Natl Acad Sci U S A 2008; 105:17384-9. [PMID: 18987324 DOI: 10.1073/pnas.0802596105] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The atmospheric dioxygen (O(2)) is produced at a tetramanganese complex bound to the proteins of photosystem II (PSII). To investigate product inhibition at elevated oxygen partial pressure (pO(2) ranging from 0.2 to 16 bar), we monitored specifically the redox reactions of the Mn complex in its catalytic S-state cycle by rapid-scan and time-resolved X-ray absorption near-edge spectroscopy (XANES) at the Mn K-edge. By using a pressure cell for X-ray measurements after laser-flash excitation of PSII particles, we found a clear pO(2) influence on the redox reactions of the Mn complex, with a similar half-effect pressure as determined (2-3 bar). However, XANES spectra and the time courses of the X-ray fluorescence collected with microsecond resolution suggested that the O(2) evolution transition itself (S(3)-->S(0)+O(2)) was not affected. Additional (nonstandard) oxidation of the Mn complex at high pO(2) explains our experimental findings more readily. Our results suggest that photosynthesis at ambient conditions is not limited by product inhibition of the O(2) formation step.
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12
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Pecoraro VL, Hsieh WY. In search of elusive high-valent manganese species that evaluate mechanisms of photosynthetic water oxidation. Inorg Chem 2008; 47:1765-78. [PMID: 18330968 DOI: 10.1021/ic7017488] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Significant progress in the understanding of biological water oxidation has occurred during the past 25 years. Today we have a somewhat clearer description of the structure of the Mn4Ca cluster and an idea of the appropriate oxidation states for the enzyme during catalysis. At issue is the mechanism of water oxidation. Depending on one's belief of the manganese ion oxidation levels at the catalytically active S4 configuration, one can invoke a variety of different processes that could lead to water oxidation. We have suggested that the most likely process is the nucleophilic attack of a water bound to calcium (or manganese) onto a highly electrophilic Mn(V)=O center. In this Article, we explore the difficulties of preparing Mn(V) in dimeric systems and the even more arduous task of definitively assigning oxidation states to such highly reactive species.
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Affiliation(s)
- Vincent L Pecoraro
- Department of Chemistry and Biophysics, The University of Michigan, Ann Arbor, Michigan 48109-1055, USA.
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13
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Dau H, Grundmeier A, Loja P, Haumann M. On the structure of the manganese complex of photosystem II: extended-range EXAFS data and specific atomic-resolution models for four S-states. Philos Trans R Soc Lond B Biol Sci 2008; 363:1237-43; discussion 1243-4. [PMID: 17989002 DOI: 10.1098/rstb.2007.2220] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The water-oxidizing manganese complex bound to the proteins of photosystem II (PSII) was studied by X-ray absorption spectroscopy on PSII membrane particles. An extended range for collection of extended X-ray absorption fine-structure (EXAFS) data was used (up to 16.6A(-1)). The EXAFS suggests the presence of two Mn-Mn distances close to 2.7A (per Mn4Ca complex); the existence of a third Mn-Mn distance below 2.9A is at least uncertain. Interestingly, a distance of 3.7A is clearly resolved in the extended-range data and tentatively assigned to a Mn-Mn distance. Taking into account the above EXAFS results (inter alia), we present a model for the structure of the PSII manganese complex, which differs from previous atomic-resolution models. Emphasizing the hypothetical character, we propose for all semi-stable S-states: (i) a structure of the Mn4Ca(mu-O)n core, (ii) a model of the amino acid environment, and (iii) assignments of distinct Mn oxidation states to all the individual Mn ions. This specific working model may permit discussion, verification and invalidation of its various features in comparison with experimental and theoretical findings.
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Affiliation(s)
- Holger Dau
- Freie Universität Berlin, FB Physik, Arnimallee 14, 14195 Berlin, Germany.
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14
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Das S, Mukhopadhyay S. Oxidation of N
III
and N
–I
by an {Mn
4
O
6
}
4+
Core in Aqueous Media: Proton‐Coupled Electron Transfer. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700363] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Suranjana Das
- Department of Chemistry, Jadavpur University, Calcutta 700 032, India
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15
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Dau H, Haumann M. Time-resolved X-ray spectroscopy leads to an extension of the classical S-state cycle model of photosynthetic oxygen evolution. PHOTOSYNTHESIS RESEARCH 2007; 92:327-43. [PMID: 17333506 DOI: 10.1007/s11120-007-9141-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Accepted: 01/16/2007] [Indexed: 05/14/2023]
Abstract
In oxygenic photosynthesis, a complete water oxidation cycle requires absorption of four photons by the chlorophylls of photosystem II (PSII). The photons can be provided successively by applying short flashes of light. Already in 1970, Kok and coworkers [Photochem Photobiol 11:457-475, 1970] developed a basic model to explain the flash-number dependence of O2 formation. The third flash applied to dark-adapted PSII induces the S3-->S4-->S0 transition, which is coupled to dioxygen formation at a protein-bound Mn4Ca complex. The sequence of events leading to dioxygen formation and the role of Kok's enigmatic S4-state are only incompletely understood. Recently we have shown by time-resolved X-ray spectroscopy that in the S3-->S0 transition an interesting intermediate is formed, prior to the onset of O-O bond formation [Haumann et al. Science 310:1019-1021, 2005]. The experimental results of the time-resolved X-ray experiments are discussed. The identity of the reaction intermediate is considered and the question is addressed how the novel intermediate is related to the S4-state proposed in 1970 by Bessel Kok. This leads us to an extension of the classical S-state cycle towards a basic model which describes sequence and interplay of electron and proton abstraction events at the donor side of PSII [Dau and Haumann, Science 312:1471-1472, 2006].
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Affiliation(s)
- Holger Dau
- FB Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
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16
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Das S, Bhattacharyya J, Mukhopadhyay S. Mechanistic Studies on the Oxidation of Glyoxylic and Pyruvic Acid by a [Mn4O6]4+ Core in Aqueous Media: Kinetics of Oxo-Bridge Protonation. Helv Chim Acta 2006. [DOI: 10.1002/hlca.200690186] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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Grabolle M, Haumann M, Müller C, Liebisch P, Dau H. Rapid Loss of Structural Motifs in the Manganese Complex of Oxygenic Photosynthesis by X-ray Irradiation at 10–300 K. J Biol Chem 2006; 281:4580-8. [PMID: 16352605 DOI: 10.1074/jbc.m509724200] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Structural changes upon photoreduction caused by x-ray irradiation of the water-oxidizing tetramanganese complex of photosystem II were investigated by x-ray absorption spectroscopy at the manganese K-edge. Photoreduction was directly proportional to the x-ray dose. It was faster in the higher oxidized S2 state than in S1; seemingly the oxidizing potential of the metal site governs the rate. X-ray irradiation of the S1 state at 15 K initially caused single-electron reduction to S0* accompanied by the conversion of one di-mu-oxo bridge between manganese atoms, previously separated by approximately 2.7 A, to a mono-mu-oxo motif. Thereafter, manganese photoreduction was 100 times slower, and the biphasic increase in its rate between 10 and 300 K with a breakpoint at approximately 200 K suggests that protein dynamics is rate-limiting the radical chemistry. For photoreduction at similar x-ray doses as applied in protein crystallography, halfway to the final Mn(II)4 state the complete loss of inter-manganese distances <3 A was observed, even at 10 K, because of the destruction of mu-oxo bridges between manganese ions. These results put into question some structural attributions from recent protein crystallography data on photosystem II. It is proposed to employ controlled x-ray photoreduction in metalloprotein research for: (i) population of distinct reduced states, (ii) estimating the redox potential of buried metal centers, and (iii) research on protein dynamics.
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Affiliation(s)
- Markus Grabolle
- Freie Universität Berlin, FB Physik, Arnimallee 14, D-14195 Berlin, Germany
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18
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Haumann M, Liebisch P, Müller C, Barra M, Grabolle M, Dau H. Photosynthetic O2 formation tracked by time-resolved x-ray experiments. Science 2005; 310:1019-21. [PMID: 16284178 DOI: 10.1126/science.1117551] [Citation(s) in RCA: 351] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Plants and cyanobacteria produce atmospheric dioxygen from water, powered by sunlight and catalyzed by a manganese complex in photosystem II. A classic S-cycle model for oxygen evolution involves five states, but only four have been identified. The missing S4 state is particularly important because it is directly involved in dioxygen formation. Now progress comes from an x-ray technique that can monitor redox and structural changes in metal centers in real time with 10-microsecond resolution. We show that in the O2-formation step, an intermediate is formed--the enigmatic S4 state. Its creation is identified with a deprotonation process rather than the expected electron-transfer mechanism. Subsequent electron transfer would give an additional S4' state, thus extending the fundamental S-state cycle of dioxygen formation.
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Affiliation(s)
- M Haumann
- Freie Universität Berlin, FB Physik, Arnimallee 14, D-14195 Berlin, Germany.
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19
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Löscher S, Zebger I, Andersen LK, Hildebrandt P, Meyer-Klaucke W, Haumann M. The structure of the Ni-Fe site in the isolated HoxC subunit of the hydrogen-sensing hydrogenase from Ralstonia eutropha. FEBS Lett 2005; 579:4287-91. [PMID: 16051223 DOI: 10.1016/j.febslet.2005.06.063] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Revised: 06/16/2005] [Accepted: 06/28/2005] [Indexed: 10/25/2022]
Abstract
The regulatory Ni-Fe hydrogenase (RH) from Ralstonia eutropha which forms a [HoxBC]2 complex functions as a hydrogen sensor under aerobic conditions. We have studied a novel Strep-tag isolate of the RH large subunit, HoxC(ST), which lacks the Fe-S clusters of HoxB, allowing for structure determination of the catalytic site by X-ray absorption spectroscopy both at the Ni and, for the first time, also at the Fe K-edge. This technique, together with Fourier-transform infrared spectroscopy, revealed a Ni-Fe site with [O1(CysS)2Ni(II)(mu-SCys)2Fe(II)(CN)2(CO)] structure in about 50% of HoxC(ST) and a [(CysS)2Fe(II)(CN)2(CO)] site lacking Ni in the remainder protein. Possibly both sites may be intermediates in the maturation process of the RH.
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Affiliation(s)
- Simone Löscher
- Freie Universität Berlin, FB Physik, Arnimallee 14, D-14195 Berlin, Germany
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20
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Buhrke T, Löscher S, Lenz O, Schlodder E, Zebger I, Andersen LK, Hildebrandt P, Meyer-Klaucke W, Dau H, Friedrich B, Haumann M. Reduction of unusual iron-sulfur clusters in the H2-sensing regulatory Ni-Fe hydrogenase from Ralstonia eutropha H16. J Biol Chem 2005; 280:19488-95. [PMID: 15764814 DOI: 10.1074/jbc.m500601200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The regulatory Ni-Fe hydrogenase (RH) from Ralstonia eutropha functions as a hydrogen sensor. The RH consists of the large subunit HoxC housing the Ni-Fe active site and the small subunit HoxB containing Fe-S clusters. The heterolytic cleavage of H(2) at the Ni-Fe active site leads to the EPR-detectable Ni-C state of the protein. For the first time, the simultaneous but EPR-invisible reduction of Fe-S clusters during Ni-C state formation was demonstrated by changes in the UV-visible absorption spectrum as well as by shifts of the iron K-edge from x-ray absorption spectroscopy in the wild-type double dimeric RH(WT) [HoxBC](2) and in a monodimeric derivative designated RH(stop) lacking the C-terminal 55 amino acids of HoxB. According to the analysis of iron EXAFS spectra, the Fe-S clusters of HoxB pronouncedly differ from the three Fe-S clusters in the small subunits of crystallized standard Ni-Fe hydrogenases. Each HoxBC unit of RH(WT) seems to harbor two [2Fe-2S] clusters in addition to a 4Fe species, which may be a [4Fe-3S-3O] cluster. The additional 4Fe-cluster was absent in RH(stop). Reduction of Fe-S clusters in the hydrogen sensor RH may be a first step in the signal transduction chain, which involves complex formation between [HoxBC](2) and tetrameric HoxJ protein, leading to the expression of the energy converting Ni-Fe hydrogenases in R. eutropha.
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Affiliation(s)
- Thorsten Buhrke
- Humboldt-Universität zu Berlin, Institut für Biologie/Mikrobiologie, Berlin, Germany
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Burgdorf T, Löscher S, Liebisch P, Van der Linden E, Galander M, Lendzian F, Meyer-Klaucke W, Albracht SPJ, Friedrich B, Dau H, Haumann M. Structural and oxidation-state changes at its nonstandard Ni-Fe site during activation of the NAD-reducing hydrogenase from Ralstonia eutropha detected by X-ray absorption, EPR, and FTIR spectroscopy. J Am Chem Soc 2005; 127:576-92. [PMID: 15643882 DOI: 10.1021/ja0461926] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Structure and oxidation state of the Ni-Fe cofactor of the NAD-reducing soluble hydrogenase (SH) from Ralstonia eutropha were studied employing X-ray absorption spectroscopy (XAS) at the Ni K-edge, EPR, and FTIR spectroscopy. The SH comprises a nonstandard (CN)Ni-Fe(CN)(3)(CO) site; its hydrogen-cleavage reaction is resistant against inhibition by dioxygen and carbon monoxide. Simulations of the XANES and EXAFS regions of XAS spectra revealed that, in the oxidized SH, the Ni(II) is six-coordinated ((CN)O(3)S(2)); only two of the four conserved cysteines, which bind the Ni in standard Ni-Fe hydrogenases, provide thiol ligands to the Ni. Upon the exceptionally rapid reductive activation of the SH by NADH, an oxygen species is detached from the Ni; hydrogen may subsequently bind to the vacant coordination site. Prolonged reducing conditions cause the two thiols that are remote from the Ni in the native SH to become direct Ni ligands, creating a standardlike Ni(II)(CysS)(4) site, which could be further reduced to form the Ni-C (Ni(III)-H(-)) state. The Ni-C state does not seem to be involved in hydrogen cleavage. Two site-directed mutants (HoxH-I64A, HoxH-L118F) revealed structural changes at their Ni sites and were employed to further dissect the role of the extra CN ligand at the Ni. It is proposed that the predominant coordination by (CN),O ligands stabilizes the Ni(II) oxidation state throughout the catalytic cycle and is a prerequisite for the rapid activation of the SH in the presence of oxygen.
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Affiliation(s)
- Tanja Burgdorf
- Humboldt-Universität zu Berlin, Mikrobiologie, Chausseestr. 117, D-10115 Berlin, Germany
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Dau H, Liebisch P, Haumann M. The structure of the manganese complex of Photosystem II in its dark-stable S1-state—EXAFS results in relation to recent crystallographic data. Phys Chem Chem Phys 2004. [DOI: 10.1039/b408146c] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Pospísil P, Michael H, Dittmer J, Solé VA, Dau H. Stepwise transition of the tetra-manganese complex of photosystem II to a binuclear Mn2(micro -O)2 complex in response to a temperature jump: a time-resolved structural investigation employing x-ray absorption spectroscopy. Biophys J 2003; 84:1370-86. [PMID: 12547817 PMCID: PMC1302713 DOI: 10.1016/s0006-3495(03)74952-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In oxygenic photosynthesis, water is oxidized at a protein-cofactor complex comprising four Mn atoms and, presumably, one calcium. Using multilayers of Photosystem II membrane particles, we investigated the time course of the disassembly of the Mn complex initiated by a temperature jump from 25 degrees C to 47 degrees C and terminated by rapid cooling after distinct heating periods. We monitored polarographically the oxygen-evolution activity, the amount of the Y(D)(ox) radical and of released Mn(2+) by EPR spectroscopy, and the structure of the Mn complex by x-ray absorption spectroscopy (XAS, EXAFS). Using a novel approach to analyze time-resolved EXAFS data, we identify three distinct phases of the disassembly process: (1) Loss of the oxygen-evolution activity and reduction of Y(D)(ox) occur simultaneously (k(1) = 1.0 min(-1)). EXAFS spectra reveal the concomitant loss of an absorber-backscatterer interaction between heavy atoms separated by approximately 3.3 A, possibly related to Ca release. (2) Subsequently, two Mn(III) or Mn(IV) ions seemingly separated by approximately 2.7 A in the native complex are reduced to Mn(II) and released (k(2) = 0.18 min(-1)). The x-ray absorption spectroscopy data is highly suggestive that the two unreleased Mn ions form a di- micro -oxo bridged Mn(III)(2) complex. (3) Finally, the tightly-bound Mn(2)( micro -O)(2) unit is slowly reduced and released (k(3) = 0.014 min(-1)).
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Affiliation(s)
- Pavel Pospísil
- Freie Universität Berlin, FB Physik, D-14195 Berlin, Germany
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The first macrocyclic “layer-to-layer” type tetranuclear copper(II) complex: structure, stability and unprecedented catalase-like activity. INORG CHEM COMMUN 2002. [DOI: 10.1016/s1387-7003(02)00649-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Krüer M, Haumann M, Meyer-Klaucke W, Thauer RK, Dau H. The role of zinc in the methylation of the coenzyme M thiol group in methanol:coenzyme M methyltransferase from Methanosarcina barkeri. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:2117-23. [PMID: 11985589 DOI: 10.1046/j.1432-1033.2002.02860.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Methanol:coenzyme M methyltransferase from methanogenic archaea is a cobalamin-dependent enzyme composed of three different subunits: MtaA, MtaB and MtaC. MtaA is a zinc protein that catalyzes the methylation of coenzyme M (HS-CoM) with methylcob(III)alamin. We report zinc XAFS (X-ray absorption fine structure) results indicating that, in the absence of coenzyme M, zinc is probably coordinated by a single sulfur ligand and three oxygen or nitrogen ligands. In the presence of coenzyme M, one (N/O)-ligand was replaced by sulfur, most likely due to ligation of the thiol group of coenzyme M. Mutations in His237 or Cys239, which are proposed to be involved in ligating zinc, resulted in an over 90% loss in enzyme activity and in distinct changes in the zinc ligands. In the His237-->Ala and Cys239-->Ala mutants, coenzyme M also seemed to bind efficiently by ligation to zinc indicating that some aspects of the zinc ligand environment are surprisingly uncritical for coenzyme M binding.
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Affiliation(s)
- Markus Krüer
- Max-Planck-Institut für terrestrische Mikrobiologie and Laboratorium für Mikrobiologie, Fachbereich Biologie der Philipps-Universität, Marburg, Germany
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Haumann M, Grabolle M, Neisius T, Dau H. The first room-temperature X-ray absorption spectra of higher oxidation states of the tetra-manganese complex of photosystem II. FEBS Lett 2002; 512:116-20. [PMID: 11852063 DOI: 10.1016/s0014-5793(02)02237-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The manganese (Mn) complex of photosystem II catalyzes water oxidation. For the first time, its advancement through the reaction cycle was monitored by time-resolved X-ray absorption measurements at the Mn K-edge at room temperature. The complex was stepped through its four oxidation states by nano-second-laser flashes applied to samples exposed to the X-ray beam. Time courses of the X-ray fluorescence intensity were recorded during a flash sequence. Extended X-ray absorption fine-structure spectra were recorded with the S(1), S(2), and S(3) oxidation states highly populated. The room temperature data is compatible with the formation of a third di-mu-oxo bridge between two Mn atoms upon the S(2)-->S(3) transition.
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Affiliation(s)
- Michael Haumann
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195, Berlin, Germany.
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Renger G. Photosynthetic water oxidation to molecular oxygen: apparatus and mechanism. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1503:210-28. [PMID: 11115635 DOI: 10.1016/s0005-2728(00)00227-9] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- G Renger
- Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Strasse des 17. Juni 135, D-10623, Berlin, Germany.
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Dau H, Iuzzolino L, Dittmer J. The tetra-manganese complex of photosystem II during its redox cycle - X-ray absorption results and mechanistic implications. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1503:24-39. [PMID: 11115622 DOI: 10.1016/s0005-2728(00)00230-9] [Citation(s) in RCA: 180] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Using X-ray absorption spectroscopy (XAS), relevant information on structure and oxidation state of the water-oxidizing Mn complex of photosystem II has been obtained for all four semi-stable intermediate states of its catalytic cycle. We summarize our recent XAS results and discuss their mechanistic implications. The following aspects are covered: (a) information content of X-ray spectra (pre-edge feature, edge position, extended X-ray absorption fine-structure (EXAFS), dichroism in the EXAFS of partially oriented samples); (b) S(1)-state structure; (c) X-ray edge results on oxidation state changes; (d) EXAFS results on structural changes during the S-state cycle; (e) a structural model for the Mn complex in its S(3)-state; (f) XAS-based working model for the S(2)-S(3) transition; (g) XAS-based working model for the S(0)-S(1) transition; (h) potential role of hydrogen atom abstraction by the Mn complex. Finally, we present a specific hypothesis on the mechanism of dioxygen formation during the S(3)-(S(4))-S(0) transition. According to this hypothesis, water oxidation is facilitated by manganese reduction that is coupled to proton transfer from a substrate water to bridging oxides.
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Affiliation(s)
- H Dau
- Phillips-Universität Marburg, FB Biologie, Lahnberge, D-35032, Marburg, Germany.
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