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Costentin C, Robert M, Savéant JM, Tard C. Inserting a Hydrogen-Bond Relay between Proton Exchanging Sites in Proton-Coupled Electron Transfers. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200907192] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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52
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Bao H, Zhang C, Ren Y, Zhao J. Methanol as a probe to investigate the relationship between the secondary electron donor TyrZ and the substrate water molecules in active photosystem II. CHINESE SCIENCE BULLETIN-CHINESE 2010. [DOI: 10.1007/s11434-010-0047-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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53
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Singla M, Mathur P. Oxidation of alcohols using a manganese (II) complex based on a pentakis benzimidazole amide ligand. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 74:536-543. [PMID: 19660981 DOI: 10.1016/j.saa.2009.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 05/13/2009] [Accepted: 07/01/2009] [Indexed: 05/28/2023]
Abstract
A pentakis benzimidazole based penta-amide ligand diethylenetriamine-N,N,N',N',N''-pentakis(2-methyl benzimidazolyl)penta-amide [GBDTPA] has been synthesized and utilized to prepare Mn (II) complexes of general composition [Mn(2)(GBDTPA)X(4)], where X is an exogenous anionic ligand (X = Cl(-), NO(3)(-) and Br(-)). The oxidation of alcohols has been investigated using [Mn(2)(GBDTPA)Cl(4)] as the catalyst and TBHP as an alternate source of oxygen. The respective aldehydic products have been isolated and characterized by (1)H NMR.
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Affiliation(s)
- Manisha Singla
- Department of Chemistry, Delhi University, Delhi 110007, India.
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Sugiura M, Rappaport F, Hillier W, Dorlet P, Ohno Y, Hayashi H, Boussac A. Evidence that D1-His332 in photosystem II from Thermosynechococcus elongatus interacts with the S3-state and not with the S2-state. Biochemistry 2009; 48:7856-66. [PMID: 19624137 DOI: 10.1021/bi901067b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Oxygen evolution by Photosystem II (PSII) is catalyzed by a Mn(4)Ca cluster. Thus far, from the crystallographic three-dimensional (3D) structures, seven amino acid residues have been identified as possible ligands of the Mn(4)Ca cluster. Among them, there is only one histidine, His332, which belongs to the D1 polypeptide. The relationships of the D1-His332 amino acid with kinetics and thermodynamic properties of the Mn(4)Ca cluster in the S(2)- and S(3)-states of the catalytic cycle were investigated in purified PSII from Thermosynechococcus elongatus. This was done by examining site-directed D1-His332Gln and D1-His332Ser mutants by a variety of spectroscopic techniques such as time-resolved UV-visible absorption change spectroscopy, cw- and pulse-EPR, thermoluminescence, and measurement of substrate water exchange. Both mutants grew photo-autotrophically and active PSII could be purified. On the basis of the parameters assessed in this work, the D1-His332(Gln, Ser) mutations had no effect in the S(2)-state. Electron spin-echo envelope modulation (ESEEM) spectroscopy also showed that possible interactions between the nuclear spin of the nitrogen(s) of D1-His332 with the electronic spin S = 1/2 of the Mn(4)Ca cluster in the S(2)-state were not detectable and that the D1-His332Ser mutation did not affect the detected hyperfine couplings. In contrast, the following changes were observed in the S(3)-state of the D1-His332 mutants: (1) The redox potential of the S(3)/S(2) couple was slightly increased by < or = 20 meV, (2) The S(3)-EPR spectrum was slightly modified, (3) The D1-His332Gln mutation resulted in a approximately 3 fold decrease of the slow (tightly bound) exchange rate and a approximately 2 fold increase of the fast exchange rate of the water substrate molecules. All these results suggest that the D1-His332 would be more involved in S(3) than in S(2). This could be one element of the conformational changes put forward in the S(2) to S(3) transition.
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Affiliation(s)
- Miwa Sugiura
- Cell-Free Science and Technology Research Center, Ehime University, Bunkyo-cho, Matsuyama Ehime, 790-8577, Japan.
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Syntheses, structures and electrochemistry of manganese(III) complexes derived from N,N′-o-phenylenebis(3-ethoxysalicylaldimine): Efficient catalyst for styrene epoxidation. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.04.034] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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56
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Sala X, Romero I, Rodríguez M, Escriche L, Llobet A. Molekulare Katalysatoren für die Oxidation von Wasser zu Disauerstoff. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200802659] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Sala X, Romero I, Rodríguez M, Escriche L, Llobet A. Molecular Catalysts that Oxidize Water to Dioxygen. Angew Chem Int Ed Engl 2009; 48:2842-52. [DOI: 10.1002/anie.200802659] [Citation(s) in RCA: 376] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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58
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Francàs L, Sala X, Benet-Buchholz J, Escriche L, Llobet A. A Ru-Hbpp-based water-oxidation catalyst anchored on rutile TiO2. CHEMSUSCHEM 2009; 2:321-329. [PMID: 19308921 DOI: 10.1002/cssc.200800191] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Two organic ligands based on bis-(2-pyridyl)pyrazole (Hbpp) functionalized with a para-methylenebenzoic acid (Hbpp-R(a)) or its ester derivative (Hbpp-R(e)) were prepared and characterized. The ester-functionalized ligand was then used to prepare a series of related dinuclear ruthenium complexes of general formula [Ru(II)2(L-L)(bpp-R(n))(trpy)2](m+) (L-L=mu-Cl, mu-acetato, or (H2O)2; n=e or a; trpy=2,2':6',2''-terpyridine; m=2 or 3). The complexes were characterized in solution by 1D and 2D NMR spectroscopy, UV/Vis spectroscopy, and electrochemical techniques. The [Ru(II)2(mu-Cl)(bpp-R(e))(trpy)2](PF6)(2) complex was further characterized in the solid state by X-ray diffraction. The complexes containing the free carboxylic acid ligand were anchored onto rutile TiO2 and treated with 0.1 M triflic acid solution to generate the homologous water-oxidation catalysts TiO(2)-[Ru(II) (2)(H2O)(2)(bpp-R(a))(trpy)2]2+. This new hybrid material catalytically oxidizes water to molecular oxygen in a heterogeneous manner using Ce(IV) as chemical oxidant. The generation of molecular oxygen is accompanied by the formation of carbon dioxide as well as some leaching of the Ru catalyst.
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Affiliation(s)
- Laia Francàs
- Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain
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Clausen J, Junge W. The terminal reaction cascade of water oxidation: proton and oxygen release. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:1311-8. [PMID: 18640091 DOI: 10.1016/j.bbabio.2008.06.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Revised: 06/09/2008] [Accepted: 06/12/2008] [Indexed: 10/21/2022]
Abstract
In cyanobacteria, algae and plants Photosystem II produces the oxygen we breathe. Driven and clocked by light quanta, the catalytic Mn(4)Ca-tyrosine centre accumulates four oxidising equivalents before it abstracts four electrons from water, liberating dioxygen and protons. Aiming at intermediates of the terminal four-electron cascade, we previously have suppressed this reaction by elevating the oxygen pressure, thereby stabilising one redox intermediate. Here, we established a similar suppression by increasing the proton concentration. Data were analysed in terms of only one (peroxy) redox intermediate between the fourfold oxidised Mn(4)Ca-tyrosine centre and oxygen release. The surprising result was that the release into the bulk of one proton per dioxygen is linked to the first and rate-limiting electron transfer in the cascade rather than to the second which produces free oxygen. The penultimate intermediate might thus be conceived as a fully deprotonated peroxy-moiety.
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Affiliation(s)
- Juergen Clausen
- Abteilung Biophysik, Fachbereich Biologie/Chemie, Universität Osnabrück, Osnabrück, Germany
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60
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Boussac A, Sugiura M, Lai TL, Rutherford AW. Low-temperature photochemistry in photosystem II from Thermosynechococcus elongatus induced by visible and near-infrared light. Philos Trans R Soc Lond B Biol Sci 2008; 363:1203-10; discussion 1210. [PMID: 17965006 DOI: 10.1098/rstb.2007.2216] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The active site for water oxidation in photosystem II (PSII) consists of a Mn4Ca cluster close to a redox-active tyrosine residue (TyrZ). The enzyme cycles through five sequential oxidation states (S0 to S4) in the water oxidation process. Earlier electron paramagnetic resonance (EPR) work showed that metalloradical states, probably arising from the Mn4 cluster interacting with TyrZ., can be trapped by illumination of the S0, S1 and S2 states at cryogenic temperatures. The EPR signals reported were attributed to S0TyrZ., S1TyrZ. and S2TyrZ., respectively. The equivalent states were examined here by EPR in PSII isolated from Thermosynechococcus elongatus with either Sr or Ca associated with the Mn4 cluster. In order to avoid spectral contributions from the second tyrosyl radical, TyrD., PSII was used in which Tyr160 of D2 was replaced by phenylalanine. We report that the metalloradical signals attributed to TyrZ. interacting with the Mn cluster in S0, S1, S2 and also probably the S3 states are all affected by the presence of Sr. Ca/Sr exchange also affects the non-haem iron which is situated approximately 44 A units away from the Ca site. This could relate to the earlier reported modulation of the potential of QA by the occupancy of the Ca site. It is also shown that in the S3 state both visible and near-infrared light are able to induce a similar Mn photochemistry.
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Affiliation(s)
- Alain Boussac
- DSV, iBiTec-s, SB2 SM, URA CNRS 2096, CEA Saclay, 91191 Gif sur Yvette, Cedex, France.
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61
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Ishida N, Sugiura M, Rappaport F, Lai TL, Rutherford AW, Boussac A. Biosynthetic Exchange of Bromide for Chloride and Strontium for Calcium in the Photosystem II Oxygen-evolving Enzymes. J Biol Chem 2008; 283:13330-40. [DOI: 10.1074/jbc.m710583200] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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62
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Romero I, Rodríguez M, Sens C, Mola J, Rao Kollipara M, Francàs L, Mas-Marza E, Escriche L, Llobet A. Ru Complexes That Can Catalytically Oxidize Water to Molecular Dioxygen. Inorg Chem 2008; 47:1824-34. [DOI: 10.1021/ic700911y] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Isabel Romero
- Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain, Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, E-08193 Barcelona, Spain, and Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, E-43007 Tarragona, Spain
| | - Montserrat Rodríguez
- Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain, Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, E-08193 Barcelona, Spain, and Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, E-43007 Tarragona, Spain
| | - Cristina Sens
- Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain, Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, E-08193 Barcelona, Spain, and Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, E-43007 Tarragona, Spain
| | - Joaquim Mola
- Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain, Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, E-08193 Barcelona, Spain, and Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, E-43007 Tarragona, Spain
| | - Mohan Rao Kollipara
- Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain, Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, E-08193 Barcelona, Spain, and Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, E-43007 Tarragona, Spain
| | - Laia Francàs
- Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain, Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, E-08193 Barcelona, Spain, and Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, E-43007 Tarragona, Spain
| | - Elena Mas-Marza
- Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain, Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, E-08193 Barcelona, Spain, and Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, E-43007 Tarragona, Spain
| | - Lluís Escriche
- Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain, Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, E-08193 Barcelona, Spain, and Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, E-43007 Tarragona, Spain
| | - Antoni Llobet
- Departament de Química, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain, Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, E-08193 Barcelona, Spain, and Institute of Chemical Research of Catalonia (ICIQ), Avinguda Països Catalans 16, E-43007 Tarragona, Spain
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63
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Chu CC, Bassani DM. Challenges and opportunities for photochemists on the verge of solar energy conversion. Photochem Photobiol Sci 2008; 7:521-30. [DOI: 10.1039/b800113h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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64
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Terasaki N, Yamamoto N, Tamada K, Hattori M, Hiraga T, Tohri A, Sato I, Iwai M, Iwai M, Taguchi S, Enami I, Inoue Y, Yamanoi Y, Yonezawa T, Mizuno K, Murata M, Nishihara H, Yoneyama S, Minakata M, Ohmori T, Sakai M, Fujii M. Bio-photosensor: Cyanobacterial photosystem I coupled with transistor via molecular wire. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:653-9. [PMID: 17184727 DOI: 10.1016/j.bbabio.2006.11.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2006] [Revised: 11/06/2006] [Accepted: 11/09/2006] [Indexed: 11/17/2022]
Abstract
We report on the first successful output of electrons directly from photosystem I (PSI) of thermophilic cyanobacteria to the gate of a field-effect transistor (FET) by bypassing electron flow via a newly designed molecular wire, i.e., artificial vitamin K(1), and a gold nanoparticle; in short, this newly manufactured photosensor employs a bio-functional unit as the core of the device. Photo-electrons generated by the irradiation of molecular complexes composed of reconstituted PSI on the gate were found to control the FET. This PSI-bio-photosensor can be used to interpret gradation in images. This PSI-FET system is moreover sufficiently stable for use exceeding a period of 1 year.
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Affiliation(s)
- Nao Terasaki
- Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8857, Japan
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65
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Kiang NY, Segura A, Tinetti G, Blankenship RE, Cohen M, Siefert J, Crisp D, Meadows VS. Spectral signatures of photosynthesis. II. Coevolution with other stars and the atmosphere on extrasolar worlds. ASTROBIOLOGY 2007; 7:252-74. [PMID: 17407410 DOI: 10.1089/ast.2006.0108] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
As photosynthesis on Earth produces the primary signatures of life that can be detected astronomically at the global scale, a strong focus of the search for extrasolar life will be photosynthesis, particularly photosynthesis that has evolved with a different parent star. We take previously simulated planetary atmospheric compositions for Earth-like planets around observed F2V and K2V, modeled M1V and M5V stars, and around the active M4.5V star AD Leo; our scenarios use Earth's atmospheric composition as well as very low O2 content in case anoxygenic photosynthesis dominates. With a line-by-line radiative transfer model, we calculate the incident spectral photon flux densities at the surface of the planet and under water. We identify bands of available photosynthetically relevant radiation and find that photosynthetic pigments on planets around F2V stars may peak in absorbance in the blue, K2V in the red-orange, and M stars in the near-infrared, in bands at 0.93-1.1 microm, 1.1-1.4 microm, 1.5-1.8 microm, and 1.8-2.5 microm. However, underwater organisms will be restricted to wavelengths shorter than 1.4 microm and more likely below 1.1 microm. M star planets without oxygenic photosynthesis will have photon fluxes above 1.6 microm curtailed by methane. Longer-wavelength, multi-photo-system series would reduce the quantum yield but could allow for oxygenic photosystems at longer wavelengths. A wavelength of 1.1 microm is a possible upper cutoff for electronic transitions versus only vibrational energy; however, this cutoff is not strict, since such energetics depend on molecular configuration. M star planets could be a half to a tenth as productive as Earth in the visible, but exceed Earth if useful photons extend to 1.1 microm for anoxygenic photosynthesis. Under water, organisms would still be able to survive ultraviolet flares from young M stars and acquire adequate light for growth.
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Affiliation(s)
- Nancy Y Kiang
- NASA Goddard Institute for Space Studies, New York, New York 10025, USA.
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66
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Beghidja C, Rogez G, Welter R. Synthesis, crystal structure and magnetic properties of a new mixed-valence [Mn4IIIMnII] pentanuclear complex. NEW J CHEM 2007. [DOI: 10.1039/b707170a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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67
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Sabater L, Hureau C, Blain G, Guillot R, Thuéry P, Rivière E, Aukauloo A. Chemical and Electrochemical Behaviours of a New Phenolato-Bridged Complex [(L)MnIIMnII(L)]2+. Pathways to Mononuclear Chlorido [(L)MnII/III/IVCl]0/1/2+ and Dinuclear Mono-µ-Oxido [(L)MnIII(µ-O)MnIII/IV(L)]2+/3+ Species. Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200600274] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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68
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Ren P, Ding B, Shi W, Wang Y, Lu T, Cheng P. 2D and 3D sulfate-water supramolecular networks templated via triazole-nickel(II) complexes. Inorganica Chim Acta 2006. [DOI: 10.1016/j.ica.2006.04.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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69
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Shcolnick S, Keren N. Metal homeostasis in cyanobacteria and chloroplasts. Balancing benefits and risks to the photosynthetic apparatus. PLANT PHYSIOLOGY 2006; 141:805-10. [PMID: 16825338 PMCID: PMC1489909 DOI: 10.1104/pp.106.079251] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Affiliation(s)
- Sigal Shcolnick
- Department of Plant and Environmental Sciences, Alexander Silberman Institute of Life Sciences, Hebrew University, Jerusalem 91904, Israel
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70
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Sun CY, Gao S, Jin LP. Hydrothermal Syntheses, Architectures and Magnetic Properties of Six Novel MnII Coordination Polymers with Mixed Ligands. Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200501155] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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71
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Abstract
Water oxidation at photosystem II Mn-cluster is mediated by the redox-active tyrosine Y(Z). We calculated the redox potential (E(m)) of Y(Z) and its symmetrical counterpart Y(D), by solving the linearized Poisson-Boltzmann equation. The calculated E(m)(Y( )/Y(-)) were +926 mV/+694 mV for Y(Z)/Y(D) with the Mn-cluster in S2 state. Together with the asymmetric position of the Mn-cluster relative to Y(Z/D), differences in H-bond network between Y(Z) (Y(Z)/D1-His(190)/D1-Asn(298)) and Y(D) (Y(D)/D2-His(189)/D2-Arg(294)/CP47-Glu(364)) are crucial for E(m)(Y(Z/D)). When D1-His(190) is protonated, corresponding to a thermally activated state, the calculated E(m)(Y(Z)) was +1216 mV, which is as high as the E(m) for P(D1/D2). We observed deprotonation at CP43-Arg(357) upon S-state transition, which may suggest its involvement in the proton exit pathway. E(m)(Y(D)) was affected by formation of P(D2)(+) (but not P(D1)(+)) and sensitive to the protonation state of D2-Arg(180). This points to an electrostatic link between Y(D) and P(D2).
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Affiliation(s)
- Hiroshi Ishikita
- Institute of Chemistry and Biochemistry, Free University of Berlin, Berlin, Germany
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72
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Sabater L, Hureau C, Guillot R, Aukauloo A. Influence of the Electrochemical Conversion of [(LH)MnIICl2] into [(L)MnIIICl]+ on the Protonic State of a Phenol-Containing Ligand. Inorg Chem 2006; 45:2373-5. [PMID: 16529448 DOI: 10.1021/ic051882b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A bischloromanganese(II) complex [(LH)MnCl2] (1), where LH is the pentadentate ligand N,N-bis(2-pyridylmethyl)-N'-salicylidene- ethane-1,2-diamine, has been synthesized. Elemental analysis, UV-visible, and cyclic voltammetry experiments showed that the phenol function of the ligand LH remains protonated. Exhaustive electrolysis at 1.0 V vs SCE led to the formation of the Mn(III) derivative [(L)MnCl]+ (3) with the concomitant expulsion of H+ and Cl-. The formation of the Mn(III) species was confirmed by UV-visible spectroscopy and X-ray crystallography. Complex 1 could be regenerated by the reduction of complex 3 in the presence of H+ and Cl-.
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Affiliation(s)
- Laurent Sabater
- Laboratoire de Chimie Inorganique and Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris-Sud, 91405 Orsay, France
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73
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74
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Hureau C, Anxolabéhère-Mallart E, Blondin G, Rivière E, Nierlich M. Synthesis, Structure and Characterisation of a New Trinuclear Di-μ-phenolato-μ-carboxylato MnIIIMnIIMnIII Complex with a Bulky Pentadentate Ligand: Chemical Access to Mononuclear MnIV-OH Entities. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200500501] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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75
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Keren N, Ohkawa H, Welsh EA, Liberton M, Pakrasi HB. Psb29, a conserved 22-kD protein, functions in the biogenesis of Photosystem II complexes in Synechocystis and Arabidopsis. THE PLANT CELL 2005; 17:2768-81. [PMID: 16155179 PMCID: PMC1242271 DOI: 10.1105/tpc.105.035048] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 08/15/2005] [Accepted: 08/22/2005] [Indexed: 05/04/2023]
Abstract
Photosystem II (PSII), the enzyme responsible for photosynthetic oxygen evolution, is a rapidly turned over membrane protein complex. However, the factors that regulate biogenesis of PSII are poorly defined. Previous proteomic analysis of the PSII preparations from the cyanobacterium Synechocystis sp PCC 6803 detected a novel protein, Psb29 (Sll1414), homologs of which are found in all cyanobacteria and vascular plants with sequenced genomes. Deletion of psb29 in Synechocystis 6803 results in slower growth rates under high light intensities, increased light sensitivity, and lower PSII efficiency, without affecting the PSII core electron transfer activities. A T-DNA insertion line in the PSB29 gene in Arabidopsis thaliana displays a phenotype similar to that of the Synechocystis mutant. This plant mutant grows slowly and exhibits variegated leaves, and its PSII activity is light sensitive. Low temperature fluorescence emission spectroscopy of both cyanobacterial and plant mutants shows an increase in the proportion of uncoupled proximal antennae in PSII as a function of increasing growth light intensities. The similar phenotypes observed in both plant and cyanobacterial mutants demonstrate that the function of Psb29 has been conserved throughout the evolution of oxygenic photosynthetic organisms and suggest a role for the Psb29 protein in the biogenesis of PSII.
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Affiliation(s)
- Nir Keren
- Department of Biology, Washington University, St. Louis, MO 63130, USA
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76
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Charlot MF, Boussac A, Blondin G. Towards a spin coupling model for the Mn4 cluster in Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2005; 1708:120-32. [PMID: 15949989 DOI: 10.1016/j.bbabio.2005.01.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2004] [Revised: 01/13/2005] [Accepted: 01/20/2005] [Indexed: 11/24/2022]
Abstract
The X-band EPR spectra of the IR sensitive untreated PSII and of MeOH- and NH(3)-treated PSII from spinach in the S(2)-state are simulated with collinear and rhombic g- and Mn-hyperfine tensors. The obtained principal values indicate a 1Mn(III)3Mn(IV) composition for the Mn(4) cluster. The four isotropic components of the Mn-hyperfine tensors are found in good agreement with the previously published values determined from EPR and (55)Mn-ENDOR data. Assuming intrinsic isotropic components of the Mn-hyperfine interactions identical to those of the Mn-catalase, spin density values are calculated. A Y-shape 4J-coupling scheme is explored to reproduce the spin densities for the untreated PSII. All the required criteria such as a S=1/2 ground state with a low lying excited spin state (30 cm(-1)) and an easy conversion to a S=5/2 system responsible for the g=4.1 EPR signal are shown to be satisfied with four antiferromagnetic interactions lying between -290 and -130 cm(-1).
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Affiliation(s)
- Marie-France Charlot
- Laboratoire de Chimie Inorganique, UMR 8613, LRC-CEA no. 33V, Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris-Sud, 91405 Orsay Cedex, France
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77
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Boussac A, Sugiura M, Kirilovsky D, Rutherford AW. Near-infrared-induced transitions in the manganese cluster of photosystem II: action spectra for the S2 and S3 redox states. PLANT & CELL PHYSIOLOGY 2005; 46:837-842. [PMID: 15769805 DOI: 10.1093/pcp/pci088] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Mn4Ca complex that is involved in water oxidation in PSII is affected by near-infrared (NIR) light in certain redox states and these phenomena can be monitored by electron paramagnetic resonance (EPR) at low temperature. Here we report the action spectra of the NIR effects in the S2 and S3 states in PSII from plants and the thermophilic cyanobacterium Thermosynechococcus elongatus. The action spectra obtained are very similar in both S states, indicating the presence of the same photoactive form of the Mn4Ca complex in both states. Since the chemical nature of the photoactive species is not known, an unequivocal interpretation of this result cannot be made; however, it appears to be more easily reconciled with the view that the redox state of the Mn4Ca cluster does not change from the S2 to the S3 transition, at least in those centers sensitive to NIR light. The temperature dependence of the NIR effect and the action spectra for S2 indicate the presence of structural heterogeneity in the Mn4Ca cluster.
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Affiliation(s)
- Alain Boussac
- Service de Bioénergétique, DBJC, URA CNRS 2096, CEA Saclay, 91191 Gif-sur-Yvette, France.
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78
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Hureau C, Blondin G, Charlot MF, Philouze C, Nierlich M, Césario M, Anxolabéhère-Mallart E. Synthesis, Structure, and Characterization of New Mononuclear Mn(II) Complexes. Electrochemical Conversion into New Oxo-Bridged Mn2(III,IV) Complexes. Role of Chloride Ions. Inorg Chem 2005; 44:3669-83. [PMID: 15877451 DOI: 10.1021/ic050243y] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two Mn(II) complexes are isolated and X-ray characterized, namely, cis-[(L(2))Mn(II)(Cl)(2)] (1) and [(L(3))Mn(II)Cl(OH(2))](ClO(4)) (2(ClO(4))), where L(2) and L(3) are the well-known tetradentate N,N'-dimethyl-N,N'-bis(2-pyridylmethyl)ethane-1,2-diamine and N,N'-dimethyl-N,N'-bis(2-pyridylmethyl)propane-1,3-diamine ligands, respectively. The crystal structure reveals that whereas the ligand L(2) is in the cis-alpha conformation in complex 1, the ligand L(3) is in the more unusual cis-beta conformation in 2. EPR spectra are recorded on frozen solutions for both complexes and are characteristic of Mn(II) species. Electrochemical behaviors are investigated on acetonitrile solution for both complexes and show that cation 2 exists as closely related Mn(II) species in equilibrium. For both complexes exhaustive bulk electrolyses of acetonitrile solution are performed at oxidative potential in various experimental conditions. In the presence of 2,6-lutidine and after elimination of chloride ligands, the formation of the di-mu-oxo mixed-valent complexes [(L(2))Mn(III)(mu-O)(2)Mn(IV)(L(2))](3+) (3a) and [(L(3))Mn(III)(mu-O)(2)Mn(IV)(L(3))](3+) (4) is confirmed by UV-vis and EPR spectroscopies and cyclic voltammetry. In addition crystals of 4(ClO(4))(3) were isolated, and the X-ray structure reveals the cis-alphaconformation of L(3). In the absence of 2,6-lutidine and without elimination of the exogenous chloride ions, the electrochemical oxidation of 1 leads to the formation of the mononuclear Mn(III) complex, namely, [(L(2))Mn(III)(Cl)(2)](+) (5), as confirmed by UV-vis as well as parallel mode EPR spectroscopy and cyclic voltammetry. In the same conditions, the electrochemical oxidation of complex 2 is more intricate, and a thorough analysis of EPR spectra establishes the formation of the binuclear mono-mu-oxo mixed-valent [(L(3))ClMn(III)(mu-O)Mn(IV)Cl(L(3))](3+) (6) complexes. Electrochemical conversion of Mn(II) complexes into mixed-valent Mn(2)(III,IV) oxo-bridged complexes in the presence of 2,6-lutidine is discussed. The role of the chloride ligands as well as that of L(3) in the building of oxo bridges is discussed. Differences in behavior between L(2) and L(3) are commented on.
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Affiliation(s)
- Christelle Hureau
- Laboratoire de Chimie Inorganique, UMR 8613, LCR-CEA No. 33V, Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris-Sud, France
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79
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Sabater L, Guillot R, Aukauloo A. Pillared salicylaldehyde derivatives as building blocks for the design of cofacial salen-type ligands. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.02.092] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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80
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Marlin DS, Bill E, Weyhermüller T, Bothe E, Wieghardt K. Magnetic Interactions in Dinuclear MnIIIMnIV Complexes Covalently Tethered to Organic Radicals: Spectroscopic Models for the S2Yz• State of Photosystem II. J Am Chem Soc 2005; 127:6095-108. [PMID: 15839711 DOI: 10.1021/ja042655w] [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] [Indexed: 11/30/2022]
Abstract
A series of isostructural dimeric manganese complexes of the type [(Me(4)dtne)Mn(2)(mu-O)(2)(mu-R)](2+)(X(-))(2) have been prepared and characterized. The dimanganese cores of these complexes are rigidly held together by the hexadentate ligand Me(4)dtne (Me(4)dtne = 1,2-bis(4,7-dimethyl-1,4,7-triazacyclonon-1-yl)ethane). Molecular structures for the entire series have been obtained by X-ray diffraction measurements, of which complexes 2 (R = (-)O(2)BPh), 3 (R = (-)O(2)C-PROXYL), 4 (R = (-)O(2)C-TEMPO), and 5 (R = (-)O(2)BPhNIT) are reported here (HO(2)C-PROXYL = 3-carboxy-2,2,5,5-tetramethylpyrrolidin-1-yloxy; HO(2)C-TEMPO = 4-carboxy-2,2,6,6-tetramethylpiperidin-1-yloxy; and HO(2)BPhNIT = 2-(4-(dihydroxyboranyl)-phenyl)-4,4,5,5-tetramethyl-3-oxyimidazolidin-1-oxide). The structures of 1 (R = (-)OAc) and 6 (R = (-)O(2)CPhNIT) have been reported previously (HO(2)CPhNIT = 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-3-oxyimidazolidin-1-oxide). All complexes exhibit several redox states, which have been investigated by electrochemistry. Complexes 1, 3, 4, and 6 contain a mixed-valent Mn(III)Mn(IV) core with an isolated magnetic ground state of S = 1/2. The exchange coupling between the manganese ions is strong throughout the series (J approximately -130 +/- 10 cm(-)(1), H = -2JS(1)S(2)). The radical complexes 3, 4, and 6 exhibit, in addition, long-range exchange interaction (6.9, 7.7, and 8.8 A, respectively) between the organic radical and the dimanganese core. The intramolecular anisotropic coupling was determined from cw-EPR line shape analyses at S-, X-, and Q-band frequencies and from the intensity of half-field signals detected in normal- and parallel-mode (J(d,)(z)() = -120 x 10(-)(4), -105 x 10(-)(4), and -140 x 10(-)(4) cm(-)(1), for 3, 4, and 6 respectively). Distance information was obtained for the dimanganese core and the organic radicals from these values by using a three-spin dipole model and local spin contributions for the manganese ions.
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Affiliation(s)
- Dana S Marlin
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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81
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Allen JF. A redox switch hypothesis for the origin of two light reactions in photosynthesis. FEBS Lett 2005; 579:963-8. [PMID: 15710376 DOI: 10.1016/j.febslet.2005.01.015] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2004] [Accepted: 01/04/2005] [Indexed: 11/28/2022]
Abstract
Photosynthesis provides energy in the Earth's biosphere and oxygen in its atmosphere. For oxygen to be produced, two different light reactions must operate simultaneously and in series. Known anaerobic, photosynthetic bacteria contain one or other of these photosystems, but never both. Here, I propose that the two photosystems diverged, in structure and function, from a common ancestor, within a single, continuous, anaerobic lineage. In such cells, living examples of which are predicted, the two photosystems are isoenzymes encoded by orthologous genes under co-ordinated, redox regulatory control. A redox switch responds to defined environmental conditions and selects which set of genes is expressed. In these cells, the two photosystems are thus synthesised at different times. It is further proposed that the origin of oxygen-evolving photosynthesis was a simple mutation that disabled the redox switch, permitting simultaneous expression of the two sets of genes. The two, newly co-existing photosystems became connected by shared electron carriers, allowing generation of electrochemical potential high enough to oxidise water; an inexhaustible supply of reductant; and the selective advantages and pressures of an aerobic world.
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Affiliation(s)
- John F Allen
- School of Biological Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, UK.
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82
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Gao EQ, Bai SQ, He Z, Yan CH. Tetramanganese(II) Cluster with Centered Trigonal Topology: Structure and Magnetic Properties. Inorg Chem 2005; 44:677-82. [PMID: 15679402 DOI: 10.1021/ic048699n] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new tetranuclear manganese(II) compound, [Mn4L6](ClO4)2 (L is the Schiff base derived from 2-pyridylaldehyde and 2-aminophenolate), has been synthesized and characterized structurally and magnetically. The compound is the first example of tetramanganese clusters with centered planar trigonal topology in which a central Mn(II) ion is connected with three peripheral Mn(II) ions by double phenoxo bridges, generating a trigonal Mn[(mu-phenoxo)2Mn]3 core. Magnetic studies have demonstrated a very weak ferromagnetic interaction between the central and peripheral Mn(II) ions, which leads to a high-spin ground state (S = 10). The ferromagnetic interaction has been tentatively related to distortion of the metal coordination environments after comparing the magnetic and structural data of the known Mn(II) complexes with similar bridging moieties.
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Affiliation(s)
- En-Qing Gao
- State Key Lab of Rare Earth Materials Chemistry and Applications & PKU-HKU Joint Lab in Rare Earth Materials and Bioinorganic Chemistry, Peking University, Beijing 100871, China
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83
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Iwata S, Barber J. Structure of photosystem II and molecular architecture of the oxygen-evolving centre. Curr Opin Struct Biol 2004; 14:447-53. [PMID: 15313239 DOI: 10.1016/j.sbi.2004.07.002] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Photosynthesis utilizes light energy to oxidize water molecules to molecular oxygen at the oxygen-evolving centre of photosystem II. The structure of photosystem II from the cyanobacterium Thermosynechococcus elongatus has been reported at 3.5A resolution and, for the first time, the complete molecular structure of this 650 kDa complex, including the oxygen-evolving centre, has been revealed.
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Affiliation(s)
- So Iwata
- Division of Biomedical Sciences and Department of Biological Sciences, Imperial College, London SW7 2AZ, UK.
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84
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Hureau C, Blanchard S, Nierlich M, Blain G, Rivière E, Girerd JJ, Anxolabéhère-Mallart E, Blondin G. Controlled Redox Conversion of New X-ray-Characterized Mono- and Dinuclear Heptacoordinated Mn(II) Complexes into Di-μ-oxo-dimanganese Core Complexes. Inorg Chem 2004; 43:4415-26. [PMID: 15236555 DOI: 10.1021/ic035332u] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two heptacoordinated Mn(II) complexes are isolated and X-ray characterized using the well-known tpen ligand (tpen = N,N,N',N'-tetrakis(2-pyridylmethyl)-1,2-ethanediamine): [(tpen)Mn(OH(2))](ClO(4))(2) (1(ClO(4))(2)) and [(tpen)Mn(micro-OAc)Mn(tpen)](ClO(4))(3).2H(2)O (2(ClO(4))(3).2H(2)O). Crystallographic data for 1(ClO(4))(2) at 110(2) K (respectively at 293(2) K): monoclinic, space group C2/c, a = 15.049(3) A (15.096(3) A), b = 9.932(2) A (10.105(2) A), c = 19.246(4) A (19.443(4) A), beta = 94.21(3) degrees (94.50(3) degrees ), Z = 4. Crystallographic data for 2(ClO(4))(3).0.5(C(2)H(5))(2)O at 123(2) K: triclinic, space group P, a = 12.707(3) A, b = 12.824(3) A, c = 19.052(4) A, alpha = 102.71(3) degrees, beta = 97.83(3) degrees, gamma = 98.15(3) degrees, Z = 2. Investigation of the variation upon temperature of the molar magnetic susceptibility of compound 2(ClO(4))(3).2H(2)O reveals a weak antiferromagnetic exchange interaction between the two high-spin Mn(II) ions (J = -0.65 +/- 0.05 cm(-)(1), H = -JS(1).S(2)). EPR spectra are recorded on powder samples and on frozen acetonitrile solutions, demonstrating the maintenance upon dissolution of the heptacoordination of Mn in complex 1 while complex 2 partially dissociates. Electrochemical responses of complexes 1 and 2 are investigated in acetonitrile, and bulk electrolyses are performed at oxidative potential in the presence of various amounts of 2,6-lutidine (0-2.65 equiv per Mn ion). The formation from either 1 or 2 of the mixed-valent complex [(tpen)Mn(III)(micro-O)(2)Mn(IV)(tpen)](3+) (3) is established from mass spectrometry and EPR and IR spectroscopy measurements. When reaction is started from 2, formation of [(tpen)Mn(IV)(micro-O)(2)(micro-OAc)Mn(IV)](3+) (4) is evidenced from cyclic voltammetry, EPR, and UV-vis data. The Mn vs tpen ratio in the electrogenerated complexes is accurately controlled by the quantity of additional 2,6-lutidine. The role of tpen as a base is discussed.
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Affiliation(s)
- Christelle Hureau
- Laboratoire de Chimie Inorganique, UMR 8613, LCR-CEA n degrees 33V, Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris-Sud, 91405 Orsay Cedex, France
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85
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Nowaczyk M, Berghaus C, Stoll R, Rögner M. Preliminary structural characterisation of the 33 kDa protein (PsbO) in solution studied by site-directed mutagenesis and NMR spectroscopy. Phys Chem Chem Phys 2004. [DOI: 10.1039/b407316a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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