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Pieper J. The functional role of protein dynamics in photosynthetic reaction centers investigated by elastic and quasielastic neutron scattering. EPJ WEB OF CONFERENCES 2015. [DOI: 10.1051/epjconf/20158302013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Müh F, Zouni A. The nonheme iron in photosystem II. PHOTOSYNTHESIS RESEARCH 2013; 116:295-314. [PMID: 24077892 DOI: 10.1007/s11120-013-9926-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 09/17/2013] [Indexed: 06/02/2023]
Abstract
Photosystem II (PSII), the light-driven water:plastoquinone (PQ) oxidoreductase of oxygenic photosynthesis, contains a nonheme iron (NHI) at its electron acceptor side. The NHI is situated between the two PQs QA and QB that serve as one-electron transmitter and substrate of the reductase part of PSII, respectively. Among the ligands of the NHI is a (bi)carbonate originating from CO2, the substrate of the dark reactions of oxygenic photosynthesis. Based on recent advances in the crystallography of PSII, we review the structure of the NHI in PSII and discuss ideas concerning its function and the role of bicarbonate along with a comparison to the reaction center of purple bacteria and other enzymes containing a mononuclear NHI site.
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Müh F, Glöckner C, Hellmich J, Zouni A. Light-induced quinone reduction in photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:44-65. [PMID: 21679684 DOI: 10.1016/j.bbabio.2011.05.021] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 05/20/2011] [Accepted: 05/23/2011] [Indexed: 10/18/2022]
Abstract
The photosystem II core complex is the water:plastoquinone oxidoreductase of oxygenic photosynthesis situated in the thylakoid membrane of cyanobacteria, algae and plants. It catalyzes the light-induced transfer of electrons from water to plastoquinone accompanied by the net transport of protons from the cytoplasm (stroma) to the lumen, the production of molecular oxygen and the release of plastoquinol into the membrane phase. In this review, we outline our present knowledge about the "acceptor side" of the photosystem II core complex covering the reaction center with focus on the primary (Q(A)) and secondary (Q(B)) quinones situated around the non-heme iron with bound (bi)carbonate and a comparison with the reaction center of purple bacteria. Related topics addressed are quinone diffusion channels for plastoquinone/plastoquinol exchange, the newly discovered third quinone Q(C), the relevance of lipids, the interactions of quinones with the still enigmatic cytochrome b559 and the role of Q(A) in photoinhibition and photoprotection mechanisms. This article is part of a Special Issue entitled: Photosystem II.
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Affiliation(s)
- Frank Müh
- Max-Volmer-Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, D-10623 Berlin, Germany
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Belyaeva N, Schmitt FJ, Paschenko V, Riznichenko G, Rubin A, Renger G. PS II model based analysis of transient fluorescence yield measured on whole leaves of Arabidopsis thaliana after excitation with light flashes of different energies. Biosystems 2011; 103:188-95. [DOI: 10.1016/j.biosystems.2010.09.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Revised: 09/29/2010] [Accepted: 09/30/2010] [Indexed: 11/25/2022]
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Orzechowska A, Lipińska M, Fiedor J, Chumakov A, Zając M, Ślęzak T, Matlak K, Strzałka K, Korecki J, Fiedor L, Burda K. Coupling of collective motions of the protein matrix to vibrations of the non-heme iron in bacterial photosynthetic reaction centers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1696-704. [DOI: 10.1016/j.bbabio.2010.06.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2009] [Revised: 06/23/2010] [Accepted: 06/26/2010] [Indexed: 10/19/2022]
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Rubin A, Riznichenko G. Modeling of the Primary Processes in a Photosynthetic Membrane. PHOTOSYNTHESIS IN SILICO 2009. [DOI: 10.1007/978-1-4020-9237-4_7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Belyaeva NE, Schmitt FJ, Steffen R, Paschenko VZ, Riznichenko GY, Chemeris YK, Renger G, Rubin AB. PS II model-based simulations of single turnover flash-induced transients of fluorescence yield monitored within the time domain of 100 ns-10 s on dark-adapted Chlorella pyrenoidosa cells. PHOTOSYNTHESIS RESEARCH 2008; 98:105-19. [PMID: 18937044 DOI: 10.1007/s11120-008-9374-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Accepted: 09/24/2008] [Indexed: 05/24/2023]
Abstract
The set up described in Steffen et al. (Biochemistry 40:173-180, 2001) was used to monitor in the time domain from 100 ns to 10 s single turnover flash-induced transients of the normalized fluorescence yield (SFITFY) on dark-adapted cells of the thermophilic algae Chlorella pyrenoidosa Chick. Perfect data fit was achieved within the framework of a previously proposed model for the PS II reaction pattern (Lebedeva et al., Biophysics 47:968-980, 2002; Belyaeva et al., Biophysics 51:860-872, 2006) after its modification by taking into account nonradiative decay processes including nonphotochemical quenching due to time-dependent populations of P680(+*) and (3)Car. On the basis of data reported in the literature, a consistent set of rate constants was obtained for electron transfer at the donor and acceptor sides of PS II, pH in lumen and stroma, the initial redox state of plastoquinone pool and the rate of plastoquinone oxidation. The evaluation of the rate constant values of dissipative processes due to quenching by carotenoid triplets in antennae and P680(+*)Q(A)(-*) recombination as well as the initial state populations after excitation with a single laser flash are close to that outlined in (Steffen et al., Biochemistry 44:3123-3133, 2005a). The simulations based on the model of the PS II reaction pattern provide information on the time courses of population probabilities of different PS II states. We analyzed the maximum (F(m)(STF)) and minimum (F(0)) of the normalized FL yield dependence on the rate of the recombination processes (radiative and dissipative nonradiative) and of P680(+*) reduction. The developed PS II model provides a basis for theoretical comparative analyses of time-dependent fluorescence signals, observed at different photosynthetic samples under various conditions (e.g. presence of herbicides, other stress conditions, excitation with actinic pulses of different intensity, and duration).
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Affiliation(s)
- N E Belyaeva
- Department of Biophysics, Biology Faculty of the M.V. Lomonosov Moscow State University, 119992 Moscow, Russia.
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Renger G, Renger T. Photosystem II: The machinery of photosynthetic water splitting. PHOTOSYNTHESIS RESEARCH 2008; 98:53-80. [PMID: 18830685 DOI: 10.1007/s11120-008-9345-7] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Accepted: 07/29/2008] [Indexed: 05/26/2023]
Abstract
This review summarizes our current state of knowledge on the structural organization and functional pattern of photosynthetic water splitting in the multimeric Photosystem II (PS II) complex, which acts as a light-driven water: plastoquinone-oxidoreductase. The overall process comprises three types of reaction sequences: (1) photon absorption and excited singlet state trapping by charge separation leading to the ion radical pair [Formula: see text] formation, (2) oxidative water splitting into four protons and molecular dioxygen at the water oxidizing complex (WOC) with P680+* as driving force and tyrosine Y(Z) as intermediary redox carrier, and (3) reduction of plastoquinone to plastoquinol at the special Q(B) binding site with Q(A)-* acting as reductant. Based on recent progress in structure analysis and using new theoretical approaches the mechanism of reaction sequence (1) is discussed with special emphasis on the excited energy transfer pathways and the sequence of charge transfer steps: [Formula: see text] where (1)(RC-PC)* denotes the excited singlet state (1)P680* of the reaction centre pigment complex. The structure of the catalytic Mn(4)O(X)Ca cluster of the WOC and the four step reaction sequence leading to oxidative water splitting are described and problems arising for the electronic configuration, in particular for the nature of redox state S(3), are discussed. The unravelling of the mode of O-O bond formation is of key relevance for understanding the mechanism of the process. This problem is not yet solved. A multistate model is proposed for S(3) and the functional role of proton shifts and hydrogen bond network(s) is emphasized. Analogously, the structure of the Q(B) site for PQ reduction to PQH(2) and the energetic and kinetics of the two step redox reaction sequence are described. Furthermore, the relevance of the protein dynamics and the role of water molecules for its flexibility are briefly outlined. We end this review by presenting future perspectives on the water oxidation process.
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Affiliation(s)
- Gernot Renger
- Max Volmer Laboratory for Biophysical Chemistry, Berlin Institute of Technology, Berlin, Germany.
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Schlodder E, Coleman WJ, Nixon PJ, Cohen RO, Renger T, Diner BA. Site-directed mutations at D1-His198 and D1-Thr179 of photosystem II in Synechocystis sp. PCC 6803: deciphering the spectral properties of the PSII reaction centre. Philos Trans R Soc Lond B Biol Sci 2008; 363:1197-202; discussion 1202. [PMID: 17965005 DOI: 10.1098/rstb.2007.2215] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Site-directed mutations were constructed in photosystem II of Synechocystis sp. PCC6803 in which the axial ligand, D1-His198, of special pair chlorophyll PD1 was replaced with Gln and where D1-Thr179, which overlies monomeric chlorophyll ChlD1, was replaced with His. The D1-His198Gln mutation produces a 3nm displacement to the blue of the bleaching minimum in the Soret and in the Qy region of the (P+QA--PQA) absorbance difference spectrum. To a first approximation, the bleaching can be assigned to the low-energy exciton transition of the special pair chlorophylls PD1/PD2. The D1-Thr179His mutation produces a 2nm displacement to the red of the bleaching minimum in the Qy region of the (3P-1P) absorbance difference spectrum. Analysis of the flash-induced (P+QA--PQA) and (3P-1P) absorbance difference spectra of both mutants compared with wild-type at 80K indicate that the cation of the oxidized donor P+ is predominantly localized on the chlorophyll PD1 of the special pair and that the reaction centre triplet state, produced upon charge recombination from 3[P+Pheo-], when the primary quinone electron acceptor QA is doubly reduced, is primarily localized on ChlD1.
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Affiliation(s)
- Eberhard Schlodder
- Max-Volmer-Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
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The effect of hydration on protein flexibility in photosystem II of green plants studied by quasielastic neutron scattering. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2008; 37:657-63. [PMID: 18351332 DOI: 10.1007/s00249-008-0297-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2007] [Revised: 02/14/2008] [Accepted: 02/26/2008] [Indexed: 10/22/2022]
Abstract
The effect of hydration on protein dynamics in photosystem II (PS II) membrane fragments from spinach has been investigated by using the method of quasielastic neutron scattering (QENS) at room temperature. The QENS data obtained indicate that the protein dynamics is strongly dependent on the extent of hydration. In particular, the hydration-induced activation of localized diffusive protein motions and QA- reoxidation by QB in PS II appear to be correlated in their onset at a hydration value of about 45% relative humidity (r.h.). These findings underline the crucial functional relevance of localized diffusive protein motions on the picosecond-timescale for the reactions of light-induced photosynthetic water splitting under formation of plastoquinol and molecular oxygen in PS II of green plants.
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Kern J, Renger G. Photosystem II: structure and mechanism of the water:plastoquinone oxidoreductase. PHOTOSYNTHESIS RESEARCH 2007; 94:183-202. [PMID: 17634752 DOI: 10.1007/s11120-007-9201-1] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 05/16/2007] [Indexed: 05/07/2023]
Abstract
This mini-review briefly summarizes our current knowledge on the reaction pattern of light-driven water splitting and the structure of Photosystem II that acts as a water:plastoquinone oxidoreductase. The overall process comprises three types of reaction sequences: (a) light-induced charge separation leading to formation of the radical ion pair P680+*QA(-*) ; (b) reduction of plastoquinone to plastoquinol at the QB site via a two-step reaction sequence with QA(-*) as reductant and (c) oxidative water splitting into O2 and four protons at a manganese-containing catalytic site via a four-step sequence driven by P680+* as oxidant and a redox active tyrosine YZ acting as mediator. Based on recent progress in X-ray diffraction crystallographic structure analysis the array of the cofactors within the protein matrix is discussed in relation to the functional pattern. Special emphasis is paid on the structure of the catalytic sites of PQH2 formation (QB-site) and oxidative water splitting (Mn4OxCa cluster). The energetics and kinetics of the reactions taking place at these sites are presented only in a very concise manner with reference to recent up-to-date reviews. It is illustrated that several questions on the mechanism of oxidative water splitting and the structure of the catalytic sites are far from being satisfactorily answered.
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Affiliation(s)
- Jan Kern
- Institut für Chemie, Max-Volmer-Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, 10623, Berlin, Germany.
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Chamorovsky SK, Cherepanov DA, Chamorovsky CS, Semenov AY. Correlation of electron transfer rate in photosynthetic reaction centers with intraprotein dielectric properties. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:441-8. [PMID: 17328862 DOI: 10.1016/j.bbabio.2007.01.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Revised: 12/24/2006] [Accepted: 01/15/2007] [Indexed: 11/20/2022]
Abstract
A number of the electrogenic reactions in photosystem I, photosystem II, and bacterial reaction centers (RC) were comparatively analyzed, and the variation of the dielectric permittivity (epsilon) in the vicinity of electron carriers along the membrane normal was calculated. The value of epsilon was minimal at the core of the complexes and gradually increased towards the periphery. We found that the rate of electron transfer (ET) correlated with the value of the dielectric permittivity: the fastest primary ET reactions occur in the low-polarity core of the complexes within the picosecond time range, whereas slower secondary reactions take place at the high-polarity periphery of the complexes within micro- to millisecond time range. The observed correlation was quantitatively interpreted in the framework of the Marcus theory. We calculated the reorganization energy of ET carriers using their van der Waals volumes and experimentally determined epsilon values. The electronic coupling was calculated by the empirical Moser-Dutton rule for the distance-dependent electron tunneling rate in nonadiabatic ET reactions. We concluded that the local dielectric permittivity inferred from the electrometric measurements could be quantitatively used to estimate the rate constant of ET reactions in membrane proteins with resolved atomic structure with the accuracy of less than one order of magnitude.
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Cuni A, Xiong L, Sayre R, Rappaport F, Lavergne J. Modification of the pheophytin midpoint potential in photosystem II: Modulation of the quantum yield of charge separation and of charge recombination pathways. Phys Chem Chem Phys 2004. [DOI: 10.1039/b407511k] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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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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Christen G, Steffen R, Renger G. Delayed fluorescence emitted from light harvesting complex II and photosystem II of higher plants in the 100 ns-5 micros time domain. FEBS Lett 2000; 475:103-6. [PMID: 10858497 DOI: 10.1016/s0014-5793(00)01641-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
This study presents the first report on delayed fluorescence (DF) emitted from spinach thylakoids, D1/D2/Cytb-559 preparations and solubilized light harvesting complex II (LHCII) in the ns time domain after excitation with saturating laser flashes. The use of a new commercially available multichannel plate with rapid gating permitted a sufficient suppression of detector distortions due to the strong prompt fluorescence. The following results were obtained: (a) in dark-adapted thylakoids, the DF amplitudes at 100 ns and 5 micros after each flash of a train of saturating actinic pulses exhibit characteristic period four oscillations of opposite sign: the DF amplitudes at 100 ns oscillate in the same manner as the quantum yield of prompt fluorescence, whereas those at 5 micros resemble the oscillation of the micros kinetics of P680(.) reduction in samples with an intact water oxidizing complex, (b) the quantum yield of total DF emission in the range up to a few micros is estimated to be <10(-4) for thylakoids, (c) the DF of D1/D2/Cytb-559 exhibits a monophasic decay with tau approximately 50 ns, (d) DF emission is also observed in isolated LHCII with biphasic decay kinetics characterized by tau values of 65 ns and about 800 ns, (e) in contrast to thylakoids, the amplitudes of DF in D1/D2/Cytb-559 preparations and solubilized LHCII do not exhibit any oscillation pattern and (f) all spectra of DF from the different sample types are characteristic for emission from the lowest excited singlet state of chlorophyll a. The implications of these findings and problems to be addressed in future research are briefly discussed.
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Affiliation(s)
- G Christen
- Max-Volmer-Institute for Biophysical Chemistry and Biochemistry, Technical University Berlin, Germany
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Deligiannakis Y, Hanley J, Rutherford AW. 1D- and 2D-ESEEM Study of the Semiquinone Radical QA- of Photosystem II. J Am Chem Soc 1999. [DOI: 10.1021/ja984209c] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yiannis Deligiannakis
- Contribution from The Institute of Materials Science, NCSR “Democritos”, 15310 Aghia Paraskevi Attikis, Greece, and Section de Bioénergétique, URA CNRS 2096, Département de Biologie Cellulaire et Moléculaire, CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - Jonathan Hanley
- Contribution from The Institute of Materials Science, NCSR “Democritos”, 15310 Aghia Paraskevi Attikis, Greece, and Section de Bioénergétique, URA CNRS 2096, Département de Biologie Cellulaire et Moléculaire, CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - A. William Rutherford
- Contribution from The Institute of Materials Science, NCSR “Democritos”, 15310 Aghia Paraskevi Attikis, Greece, and Section de Bioénergétique, URA CNRS 2096, Département de Biologie Cellulaire et Moléculaire, CEA Saclay, F-91191 Gif-sur-Yvette, France
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Zech SG, Kurreck J, Eckert HJ, Renger G, Lubitz W, Bittl R. Pulsed EPR measurement of the distance between P680+. and Q(A)-. in photosystem II. FEBS Lett 1997; 414:454-6. [PMID: 9315739 DOI: 10.1016/s0014-5793(97)01054-5] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Out-of-phase electron spin echo envelope modulation (ESEEM) spectroscopy was used to determine the distance between the primary donor radical cation P680+. and the quinone acceptor radical anion Q(A)-. in iron-depleted photosystem II in membrane fragments from spinach that are deprived of the water oxidizing complex. Furthermore, a lower limit for the distance between the oxidized tyrosine residue Y(Z) of polypeptide D1 and Q(A)-. could be estimated by a comparison of data gathered from samples where the electron transfer from Y(Z) to P680+. is either intact or blocked by preillumination in the presence of NH2OH.
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Affiliation(s)
- S G Zech
- Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Germany
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Stoichiometry of pigments and radical pair formation under saturating pulse excitation in D1/D2/cytb559 preparations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1997. [DOI: 10.1016/s0005-2728(96)00151-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Vasil'ev S, Bergmann A, Redlin H, Eichler HJ, Renger G. On the role of exchangeable hydrogen bonds for the kinetics of P680+. QA−. formation and P680+. Pheo−. recombination in photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1996. [DOI: 10.1016/0005-2728(96)00027-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Kurreck J, Garbers A, Reifarth F, Andréasson LE, Parak F, Renger G. Isolation and properties of PS II membrane fragments depleted of the non heme iron center. FEBS Lett 1996; 381:53-7. [PMID: 8641439 DOI: 10.1016/0014-5793(96)00061-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The functional properties and the content of non heme iron and cytochrome b559 were investigated by measuring flash induced transient changes of the relative fluorescence quantum yield and applying Mössbauer spectroscopy. It was found that untreated PS II membrane fragments contain a heterogeneous population of two types of non heme iron centers and about 2 cytochrome b559 per PS II. Twofold treatment of these samples with a recently described 'iron depletion' procedure (MacMillan, F., Lendzian, F., Renger, G. and Lubitz, W. (1995) Biochemistry 34, 3144-3156) leads to a complete loss (below the detection limit of Mössbauer spectroscopy) of the non heme iron center while more than 50% of the PS II complexes retain the functional integrity for light induced formation of the 'stable' radical pair Y(OX)(Z) P680Pheo Q(-.)(A). This sample type deprived of virtually all non heme iron in PS II provides a most suitable material for magnetic resonance studies that require an elimination of the interaction between Fe2+ and nearby radicals.
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Affiliation(s)
- J Kurreck
- Max-Volmer-Institut für Biophysikalische und Physikalische Chemie, Technische Universität Berlin, Germany
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Funk C, Schröder WP, Napiwotzki A, Tjus SE, Renger G, Andersson B. The PSII-S protein of higher plants: a new type of pigment-binding protein. Biochemistry 1995; 34:11133-41. [PMID: 7669771 DOI: 10.1021/bi00035a019] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An intrinsic 22 kDa protein of photosystem II has been shown to possess high sequence homology with the CAB gene products, but differs from these proteins by an additional putative fourth transmembrane helix. This protein, designated PSII-S in accordance with the assignment of the name psbS to its gene, has been isolated by nonionic detergents and preparative isoelectric focusing in this study. The isolated PSII-S protein was shown to bind 5 chlorophyll molecules (a and b) per protein unit and also several different kinds of carotenoids. The room temperature absorption spectrum of the Qy transition of the chlorophylls bound to the isolated protein is characterized by a broad band with a maximum at 671 nm. The 77 K fluorescence spectrum exhibits a peak at 672 nm. A single photon counting technique was applied to resolve the room temperature decay kinetics of the first excited singlet states in the chlorophyll ensemble of the PSII-S protein. The data can be satisfactorily described by triexponential kinetics with lifetimes of tau 1 = 1.8 ns, tau 2 = 4.4 ns, and tau 3 = 6.1 ns and normalized amplitudes of 0.09, 0.60, and 0.31, respectively. Circular dichroism spectra suggest that, in contrast to LHCII, virtually no pigment coupling exists in the PSII-S protein. Two copies of the PSII-S protein were found per PSII in spinach thylakoids. It displays an unusually extreme lateral heterogeneity, since the PSII beta centers located in the stroma exposed thylakoid regions contained only residual amounts of the PSII-S protein.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- C Funk
- Department of Biochemistry, Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden
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