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Effect of the P700 pre-oxidation and point mutations near A(0) on the reversibility of the primary charge separation in Photosystem I from Chlamydomonas reinhardtii. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1797:106-12. [PMID: 19761751 DOI: 10.1016/j.bbabio.2009.09.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 07/31/2009] [Accepted: 09/09/2009] [Indexed: 11/22/2022]
Abstract
Time-resolved fluorescence studies with a 3-ps temporal resolution were performed in order to: (1) test the recent model of the reversible primary charge separation in Photosystem I (Müller et al., 2003; Holwzwarth et al., 2005, 2006), and (2) to reconcile this model with a mechanism of excitation energy quenching by closed Photosystem I (with P700 pre-oxidized to P700+). For these purposes, we performed experiments using Photosystem I core samples isolated from Chlamydomonas reinhardtii wild type, and two mutants in which the methionine axial ligand to primary electron acceptor, A(0), has been change to either histidine or serine. The temporal evolution of fluorescence spectra was recorded for each preparation under conditions where the "primary electron donor," P700, was either neutral or chemically pre-oxidized to P700+. For all the preparations under study, and under neutral and oxidizing conditions, we observed multiexponential fluorescence decay with the major phases of approximately 7 ps and approximately 25 ps. The relative amplitudes and, to a minor extent the lifetimes, of these two phases were modulated by the redox state of P700 and by the mutations near A(0): both pre-oxidation of P700 and mutations caused slight deceleration of the excited state decay. These results are consistent with a model in which P700 is not the primary electron donor, but rather a secondary electron donor, with the primary charge separation event occurring between the accessory chlorophyll, A, and A(0). We assign the faster phase to the equilibration process between the excited state of the antenna/reaction center ensemble and the primary radical pair, and the slower phase to the secondary electron transfer reaction. The pre-oxidation of P700 shifts the equilibrium between the excited state and the primary radical pair towards the excited state. This shift is proposed to be induced by the presence of the positive charge on P700+. The same charge is proposed to be responsible for the fast A+A(0)(-)-->AA(0) charge recombination to the ground state and, in consequence, excitation quenching in closed reaction centers. Mutations of the A(0) axial ligand shift the equilibrium in the same direction as pre-oxidation of P700 due to the up-shift of the free energy level of the state A+A(0)(-).
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Shubin VV, Terekhova IN, Kirillov BA, Karapetyan NV. Quantum yield of P700+ photodestruction in isolated photosystem I complexes of the cyanobacterium Arthrospira platensis. Photochem Photobiol Sci 2008; 7:956-62. [PMID: 18688503 DOI: 10.1039/b719122g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photostability of P700 cation radical (P700+) was studied by evaluating the quantum yields of P700(+) photodestruction in photosystem I (PSI) complexes of the cyanobacterium Arthrospira platensis. The time courses of P700+ photodestruction in PSI trimers and monomers have been measured in aerobic conditions under selective excitation of far-red absorption band of P700+ by intense light of laser diodes. Long-term exposure of PSI complexes to 808 or 870 nm laser light caused destruction of P700+ and antenna chlorophylls. The true integral quantum yield of P700+ photodestruction calculated from these data was less than 0.7-1.4 x 10(-8). Illumination of PSI complexes by 650 nm light caused destruction of antenna chlorophylls with true quantum yield of about 6-7 x 10(-6) and damage of P700 with apparent quantum yield 2-3 x 10(-8). Preferential photodestruction of the long-wavelength antenna chlorophyll absorbing at 710 nm as compared with bulk chlorophylls was observed. About three orders of difference in magnitude between quantum yields of P700+ and bulk chlorophyll photodestruction indicates that P700+ is extremely photostable for functioning as an efficient quencher of singlet excitation energy in PSI.
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Affiliation(s)
- Vladimir V Shubin
- A.N. Bakh Institute of Biochemistry RAS, Leninsky pr. 33, 119071, Moscow, Russia
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Gibasiewicz K, Ramesh VM, Lin S, Redding K, Woodbury NW, Webber AN. Two equilibration pools of chlorophylls in the Photosystem I core antenna of Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 2007; 92:55-63. [PMID: 17611814 DOI: 10.1007/s11120-006-9125-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Accepted: 12/11/2006] [Indexed: 05/16/2023]
Abstract
Femtosecond transient absorption spectroscopy was applied for a comparative study of excitation decay in several different Photosystem I (PSI) core preparations from the green alga Chlamydomonas reinhardtii. For PSI cores with a fully interconnected network of chlorophylls, the excitation energy was equilibrated over a pool of chlorophylls absorbing at approximately 683 nm, independent of excitation wavelength [Gibasiewicz et al. J Phys Chem B 105:11498-11506, 2001; J Phys Chem B 106:6322-6330, 2002]. In preparations with impaired connectivity between chlorophylls, we have found that the spectrum of chlorophylls connected to the reaction center (i.e., with approximately 20 ps decay time) over which the excitation is equilibrated becomes excitation-wavelength-dependent. Excitation at 670 nm is finally equilibrated over chlorophylls absorbing at approximately 675 nm, whereas excitation at 695 nm or 700 nm is equilibrated over chlorophylls absorbing at approximately 683 nm. This indicates that in the vicinity of the reaction center there are two spectrally different and spatially separated pools of chlorophylls that are equally capable of effective excitation energy transfer to the reaction center. We propose that they are related to the two groups of central PSI core chlorophylls lying on the opposite sides of reaction center.
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Affiliation(s)
- Krzysztof Gibasiewicz
- School of Life Sciences, Department of Chemistry and Biochemistry and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, AZ 85287-4501, USA.
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Dashdorj N, Xu W, Cohen RO, Golbeck JH, Savikhin S. Asymmetric electron transfer in cyanobacterial Photosystem I: charge separation and secondary electron transfer dynamics of mutations near the primary electron acceptor A0. Biophys J 2004; 88:1238-49. [PMID: 15542554 PMCID: PMC1305126 DOI: 10.1529/biophysj.104.050963] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Point mutations were introduced near the primary electron acceptor sites assigned to A0 in both the PsaA and PsaB branches of Photosystem I in the cyanobacterium Synechocystis sp. PCC 6803. The residues Met688PsaA and Met668PsaB, which provide the axial ligands to the Mg2+ of the eC-A3 and eC-B3 chlorophylls, were changed to leucine and asparagine (chlorophyll notation follows Jordan et al., 2001). The removal of the ligand is expected to alter the midpoint potential of the A0/A0- redox pair and result in a change in the intrinsic charge separation rate and secondary electron transfer kinetics from A0- to A1. The dynamics of primary charge separation and secondary electron transfer were studied at 690 nm and 390 nm in these mutants by ultrafast optical pump-probe spectroscopy. The data reveal that mutations in the PsaB branch do not alter electron transfer dynamics, whereas mutations in the PsaA branch have a distinct effect on electron transfer, slowing down both the primary charge separation and the secondary electron transfer step (the latter by a factor of 3-10). These results suggest that electron transfer in cyanobacterial Photosystem I is asymmetric and occurs primarily along the PsaA branch of cofactors.
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Kumazaki S, Abiko K, Ikegami I, Iwaki M, Itoh S. Energy equilibration and primary charge separation in chlorophyll d-based photosystem I reaction center isolated from Acaryochloris marina. FEBS Lett 2002; 530:153-7. [PMID: 12387884 DOI: 10.1016/s0014-5793(02)03446-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Primary photochemistry in photosystem I (PS I) reaction center complex from Acaryochloris marina that uses chlorophyll d instead of chlorophyll a has been studied with a femtosecond spectroscopy. Upon excitation at 630 nm, almost full excitation equilibration among antenna chlorophylls and 40% of the excitation quenching by the reaction center are completed with time constants of 0.6(+/-0.1) and 4.9(+/-0.6) ps, respectively. The rise and decay of the primary charge-separated state proceed with apparent time constants of 7.2(+/-0.9) and 50(+/-10) ps, suggesting the reduction of the primary electron acceptor chlorophyll (A(0)) and its reoxidation by phylloquinone (A(1)), respectively.
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Affiliation(s)
- Shigeichi Kumazaki
- School of Materials Science, Japan Advanced Institute of Science and Technology, Tatsunokuchi, Ishikawa 923-1292, Japan.
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Gibasiewicz K, Ramesh VM, Lin S, Woodbury NW, Webber AN. Excitation Dynamics in Eukaryotic PS I from Chlamydomonas reinhardtii CC 2696 at 10 K. Direct Detection of the Reaction Center Exciton States. J Phys Chem B 2002. [DOI: 10.1021/jp014608l] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Krzysztof Gibasiewicz
- Department of Plant Biology, Department of Chemistry and Biochemistry and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe Arizona 85287-1601, USA and Department of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61−614 Poznań, Poland
| | - V. M. Ramesh
- Department of Plant Biology, Department of Chemistry and Biochemistry and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe Arizona 85287-1601, USA and Department of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61−614 Poznań, Poland
| | - Su Lin
- Department of Plant Biology, Department of Chemistry and Biochemistry and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe Arizona 85287-1601, USA and Department of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61−614 Poznań, Poland
| | - Neal W. Woodbury
- Department of Plant Biology, Department of Chemistry and Biochemistry and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe Arizona 85287-1601, USA and Department of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61−614 Poznań, Poland
| | - Andrew N. Webber
- Department of Plant Biology, Department of Chemistry and Biochemistry and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe Arizona 85287-1601, USA and Department of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61−614 Poznań, Poland
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Gibasiewicz K, Ramesh VM, Melkozernov AN, Lin S, Woodbury NW, Blankenship RE, Webber AN. Excitation Dynamics in the Core Antenna of PS I from Chlamydomonas reinhardtii CC 2696 at Room Temperature. J Phys Chem B 2001. [DOI: 10.1021/jp012089g] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Krzysztof Gibasiewicz
- Department of Plant Biology, Department of Chemistry and Biochemistry, and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1601, and Institute of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland
| | - V. M. Ramesh
- Department of Plant Biology, Department of Chemistry and Biochemistry, and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1601, and Institute of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland
| | - Alexander N. Melkozernov
- Department of Plant Biology, Department of Chemistry and Biochemistry, and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1601, and Institute of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland
| | - Su Lin
- Department of Plant Biology, Department of Chemistry and Biochemistry, and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1601, and Institute of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland
| | - Neal W. Woodbury
- Department of Plant Biology, Department of Chemistry and Biochemistry, and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1601, and Institute of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland
| | - Robert E. Blankenship
- Department of Plant Biology, Department of Chemistry and Biochemistry, and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1601, and Institute of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland
| | - Andrew N. Webber
- Department of Plant Biology, Department of Chemistry and Biochemistry, and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287-1601, and Institute of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Poznań, Poland
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Melkozernov AN, Lin S, Blankenship RE. Femtosecond transient spectroscopy and excitonic interactions in Photosystem I. J Phys Chem B 2000; 104:1651-6. [PMID: 11543525 DOI: 10.1021/jp993257w] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ultrafast dynamics of excitation transfer in the Photosystem I (PSI) core antenna from the cyanobacterium Synechocystis sp. PCC 6803 were detected at 77 K by using femtosecond transient absorption spectroscopy with selective excitation at 700, 695, and 710 nm. At low temperature, the efficiency of uphill energy transfer in the core antenna significantly decreases. As a result, the spectral profile of the PSI equilibrated antenna shifts to lower energies because of a change of chlorophyll (Chl) excited-state distribution. Observed on a 2-ns time scale, P700 photooxidation spectra are largely excitation wavelength independent. In the early time spectra, excitation of P700 induces transient photobleaching at 698 nm accompanied by a resonant photobleaching band at 683 nm decaying within 250-300 fs. Chemical oxidation of P700 does not affect the transient band at 683 nm. This band is also present in 200-fs spectra induced by selective excitation of Chls at 710 nm (red pigments C708), which suggests that this high-energy transition may reflect an excitonic interaction between pigments of the reaction center and closely located red pigments. Possible candidates for the interacting molecules in the 4-angstroms crystal structure of cyanobacterial PSI are discussed.
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Affiliation(s)
- A N Melkozernov
- Department of Chemistry and Biochemistry, Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe 85287-1604, USA
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Kumazaki S, Ikegami I, Yoshihara K. Excitation and Electron Transfer from Selectively Excited Primary Donor Chlorophyll (P700) in a Photosystem I Reaction Center. J Phys Chem A 1997. [DOI: 10.1021/jp961948b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shigeichi Kumazaki
- Institute for Molecular Science, Myodaiji, Okazaki, 444 Japan, and Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa, 199-01, Japan
| | - Isamu Ikegami
- Institute for Molecular Science, Myodaiji, Okazaki, 444 Japan, and Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa, 199-01, Japan
| | - Keitaro Yoshihara
- Institute for Molecular Science, Myodaiji, Okazaki, 444 Japan, and Faculty of Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa, 199-01, Japan
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White NTH, Beddard GS, Thorne JRG, Feehan TM, Keyes TE, Heathcote P. Primary Charge Separation and Energy Transfer in the Photosystem I Reaction Center of Higher Plants. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp9604709] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nigel T. H. White
- Department of Chemistry, University of Manchester, Manchester M13 9PL, U.K., and School of Biological Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, U.K
| | - Godfrey S. Beddard
- Department of Chemistry, University of Manchester, Manchester M13 9PL, U.K., and School of Biological Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, U.K
| | - Jonathan R. G. Thorne
- Department of Chemistry, University of Manchester, Manchester M13 9PL, U.K., and School of Biological Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, U.K
| | - Tim M. Feehan
- Department of Chemistry, University of Manchester, Manchester M13 9PL, U.K., and School of Biological Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, U.K
| | - Tia E. Keyes
- Department of Chemistry, University of Manchester, Manchester M13 9PL, U.K., and School of Biological Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, U.K
| | - Peter Heathcote
- Department of Chemistry, University of Manchester, Manchester M13 9PL, U.K., and School of Biological Sciences, Queen Mary and Westfield College, Mile End Road, London E1 4NS, U.K
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Double-reduction of A1 abolishes the EPR signal attributed to A−1: Evidence for C2 symmetry in the Photosystem I reaction centre. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1993. [DOI: 10.1016/0005-2728(93)90030-j] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Deinum G, Kramer H, Aartsma TJ, Kleinherenbrink FA, Amesz J. Fluorescence quenching in Heliobacterium chlorum by reaction centers in the charge separated state. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1991. [DOI: 10.1016/s0005-2728(05)80129-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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