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Kammel M, Kern J, Lubitz W, Bittl R. Photosystem II single crystals studied by transient EPR: the light-induced triplet state. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1605:47-54. [PMID: 12907300 DOI: 10.1016/s0005-2728(03)00063-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Transient electron paramagnetic resonance (TR EPR) at 9.8 GHz has been used to study the light-induced triplet state in single crystals of Photosystem II (PS II). The crystals were grown from a solution of PS II core complexes from the thermophilic cyanobacterium Synechococcus elongatus. The core complexes contain at least 17 subunits, including the water-oxidizing complex, and 32 chlorophyll a molecules per PS II complex. The PS II complexes are active in light-induced electron transfer and water oxidation. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with four dimers of PS II complexes per unit cell. Laser excitation was used to generate the recombination triplet state in PS II which was then studied by EPR at low temperatures (10 K). The crystal spectra show the same magnitude of the zero-field splitting (ZFS) values D, E as spectra obtained earlier for the triplet state of PS II in frozen solution. The orientation of the ZFS tensor D of the triplet state with respect to the crystallographic axes has been deduced from the analysis of angular-dependent EPR spectra. Knowledge of the orientation of the D tensor component perpendicular to the plane of the chlorophyll (D(Z)) allows an assignment on which chlorophyll of the reaction centre the triplet state is localized at low temperatures. Furthermore, the orientation of the D(X) and D(Y) components of the D tensor yielded the in-plane orientation of the respective chlorophyll in the reaction centre providing first experimental evidence for the orientation of this molecule in the PS II.
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Affiliation(s)
- Michael Kammel
- Max-Volmer-Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, D-10623, Berlin, Germany
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Lendzian F, Bittl R, Telfer A, Lubitz W. Hyperfine structure of the photoexcited triplet state 3P680 in plant PS II reaction centres as determined by pulse ENDOR spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1605:35-46. [PMID: 12907299 DOI: 10.1016/s0005-2728(03)00062-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The triplet states in plant photosystem II (PS II), 3P680, and from chlorophyll a, 3Chl a, in organic solution have been investigated using pulse ENDOR combined with repetitive laser excitation at cryogenic temperature with the aim to obtain their hyperfine (hf) structure. The large zero field splitting (ZFS) tensor of 3P680 enabled orientation selection via the electron spin resonance (EPR) field setting along the ZFS tensor axes. ENDOR spectra have been obtained for the first time also for the in-plane X- and Y-orientations of the ZFS tensor. This allowed a full determination of the hf-tensors of the three methine protons and one methyl group of 3P680. Based on the orientations of the axes of these hf-tensors, a unique orientation of the axes of the ZFS tensor of 3P680 in the Chl a molecular frame was obtained. These data serve as a structural basis for determining the orientation of 3P680 in the PS II protein complex by EPR on single crystals (see M. Kammel et al. in this issue). The data obtained represent the first complete set of the larger hf-tensors of the triplet state 3P680. They reflect the spin density distribution both in the highest occupied (HOMO) and lowest unoccupied (LUMO) orbitals. The data clearly confirm that 3P680 is a monomeric Chl a species at low temperature (T=10 K) used, as has been proposed earlier based on D- and E-values obtained from EPR and optically detected magnetic resonance (ODMR) studies. Comparison with the hf data for the cation and anion radicals of Chl a indicates a redistribution of spin densities in particular for the LUMO orbital of the triplet states. The electron spin distribution in the LUMO orbital is of special interest since it harbours the excited electron in the excited P680 singlet state, from which light-induced electron transfer proceeds. Observed shifts of hf couplings from individual nuclei of 3P680 as compared with 3Chl a in organic solution are of special interest, since they indicate specific protein interactions, e.g. hydrogen bonding, which might be used in future studies for assigning 3P680 to a particular chlorophyll molecule in PS II.
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Affiliation(s)
- Friedhelm Lendzian
- Max-Volmer-Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, PC14, Strasse des 17. Juni 135, D-10623, Berlin, Germany.
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Noguchi T. Dual role of triplet localization on the accessory chlorophyll in the photosystem II reaction center: photoprotection and photodamage of the D1 protein. PLANT & CELL PHYSIOLOGY 2002; 43:1112-6. [PMID: 12407190 DOI: 10.1093/pcp/pcf137] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Infrared absorption and electron spin resonance studies have shown that the excited triplet state of chlorophyll formed by radical pair recombination in the PSII reaction center is mainly localized on the accessory chlorophyll, which is most probably located in the D1 protein (Chl(1)). This triplet localization plays two contrasting roles, depending on the redox state of Q(A), in the process of acceptor-side photoinhibition of PSII. In the early stage of photoinhibition, in which singly reduced Q(A) is reversibly stabilized, the triplet state of Chl(1) ((3)Chl(1)*) is rapidly quenched (t(1/2) = 2-20 micro s) by the interaction with Q(A)(-), preventing formation of harmful singlet oxygen. In the next inhibitory stage, in which Q(A) is doubly reduced and then irreversibly released from the Q(A) pocket, the lifetime of (3)Chl(1)* becomes longer by more than two orders of magnitude (t(1/2) = 1-3 ms). As a result, singlet oxygen is produced around Chl(1) in the D1 protein, causing damage preferably to the D1 protein, which induces subsequent proteolytic degradation. Thus, (3)Chl(1)* functions as a switch to change from the protective to the degradative phase of the PSII reaction center by sensing either reversible or irreversible inhibited state at the Q(A) site.
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Affiliation(s)
- Takumi Noguchi
- Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki, 305-8573 Japan.
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54
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Poluektov OG, Utschig LM, Schlesselman SL, Lakshmi KV, Brudvig GW, Kothe G, Thurnauer MC. Electronic Structure of the P700Special Pair from High-Frequency Electron Paramagnetic Resonance Spectroscopy. J Phys Chem B 2002. [DOI: 10.1021/jp021465+] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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55
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Borovykh IV, Klenina IB, Proskuryakov II, Gast P, Hoff AJ. Magnetophotoselection Study of the Carotenoid Triplet State in Rhodobacter sphaeroides Reaction Centers. J Phys Chem B 2002. [DOI: 10.1021/jp0125810] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Igor V. Borovykh
- Department of Biophysics, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, The Netherlands and Institute of Basic Biological Problems RAS, Pushchino, 142290, Russia
| | - Irina B. Klenina
- Department of Biophysics, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, The Netherlands and Institute of Basic Biological Problems RAS, Pushchino, 142290, Russia
| | - Ivan I. Proskuryakov
- Department of Biophysics, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, The Netherlands and Institute of Basic Biological Problems RAS, Pushchino, 142290, Russia
| | - Peter Gast
- Department of Biophysics, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, The Netherlands and Institute of Basic Biological Problems RAS, Pushchino, 142290, Russia
| | - Arnold J. Hoff
- Department of Biophysics, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, The Netherlands and Institute of Basic Biological Problems RAS, Pushchino, 142290, Russia
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56
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Lubitz W. Pulse EPR and ENDOR studies of light-induced radicals and triplet states in photosystem II of oxygenic photosynthesis. Phys Chem Chem Phys 2002. [DOI: 10.1039/b206551g] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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57
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KAY CWM, GROMADECKI U, TÖRRING JT, WEBER S. An investigation of the structure of free-base porphycene by time-resolved electron nuclear double resonance and density functional theory on the photoexcited triplet state. Mol Phys 2001. [DOI: 10.1080/00268970110054520] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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58
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Borovykh IV, Proskuryakov II, Klenina IB, Gast P, Hoff AJ. Magnetophotoselection Study of the Lowest Excited Triplet State of the Primary Donor in Photosynthetic Bacteria. J Phys Chem B 2000. [DOI: 10.1021/jp993780a] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Igor V. Borovykh
- Department of Biophysics, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Basic Biological Problems RAS, Pushchino, 142292, Russia
| | - Ivan I. Proskuryakov
- Department of Biophysics, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Basic Biological Problems RAS, Pushchino, 142292, Russia
| | - Irina B. Klenina
- Department of Biophysics, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Basic Biological Problems RAS, Pushchino, 142292, Russia
| | - Peter Gast
- Department of Biophysics, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Basic Biological Problems RAS, Pushchino, 142292, Russia
| | - Arnold J. Hoff
- Department of Biophysics, Huygens Laboratory, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Basic Biological Problems RAS, Pushchino, 142292, Russia
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59
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Zybailov B, van der Est A, Zech SG, Teutloff C, Johnson TW, Shen G, Bittl R, Stehlik D, Chitnis PR, Golbeck JH. Recruitment of a foreign quinone into the A(1) site of photosystem I. II. Structural and functional characterization of phylloquinone biosynthetic pathway mutants by electron paramagnetic resonance and electron-nuclear double resonance spectroscopy. J Biol Chem 2000; 275:8531-9. [PMID: 10722691 DOI: 10.1074/jbc.275.12.8531] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Electron paramagnetic resonance (EPR) and electron-nuclear double resonance studies of the photosystem (PS) I quinone acceptor, A(1), in phylloquinone biosynthetic pathway mutants are described. Room temperature continuous wave EPR measurements at X-band of whole cells of menA and menB interruption mutants show a transient reduction and oxidation of an organic radical with a g-value and anisotropy characteristic of a quinone. In PS I complexes, the continuous wave EPR spectrum of the photoaccumulated Q(-) radical, measured at Q-band, and the electron spin-polarized transient EPR spectra of the radical pair P700(+) Q(-), measured at X-, Q-, and W-bands, show three prominent features: (i) Q(-) has a larger g-anisotropy than native phylloquinone, (ii) Q(-) does not display the prominent methyl hyperfine couplings attributed to the 2-methyl group of phylloquinone, and (iii) the orientation of Q(-) in the A(1) site as derived from the spin polarization is that of native phylloquinone in the wild type. Electron spin echo modulation experiments on P700(+) Q(-) show that the dipolar coupling in the radical pair is the same as in native PS I, i.e. the distance between P700(+) and Q(-) (25.3 +/- 0.3 A) is the same as between P700(+) and A(1)(-) in the wild type. Pulsed electron-nuclear double resonance studies show two sets of resolved spectral features with nearly axially symmetric hyperfine couplings. They are tentatively assigned to the two methyl groups of the recruited plastoquinone-9, and their difference indicates a strong inequivalence among the two groups when in the A(1) site. These results show that Q (i) functions in accepting an electron from A(0)(-) and in passing the electron forward to the iron-sulfur clusters, (ii) occupies the A(1) site with an orientation similar to that of phylloquinone in the wild type, and (iii) has spectroscopic properties consistent with its identity as plastoquinone-9.
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Affiliation(s)
- B Zybailov
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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60
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van der Est A, Hager-Braun C, Leibl W, Hauska G, Stehlik D. Transient electron paramagnetic resonance spectroscopy on green-sulfur bacteria and heliobacteria at two microwave frequencies. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1409:87-98. [PMID: 9838060 DOI: 10.1016/s0005-2728(98)00152-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Spin polarized transient EPR spectra taken at X-band (9 GHz) and K-band (24 GHz) of membrane fragments of Chlorobium tepidum and Heliobacillus mobilis are presented along with the spectra of two fractions obtained in the purification of reaction centers (RC) from C. tepidum. The lifetime of P+. is determined by measuring the decay of the EPR signals following relaxation of the initial spin polarization. All samples except one of the RC fractions show evidence of light induced charge separation and formation of chlorophyll triplet states. The lifetime of P+. is found to be biexponential with components of 1.5 ms and 30 ms for C. tepidum and 1.0 and 4.5 ms for Hc. mobilis at 100 K. In both cases, the rates are assigned to recombination from F-X. The spin polarized radical pair spectra for both species are similar and those from Hc. mobilis at room temperature and 100 K are identical. In all cases, an emission/absorption polarization pattern with a net absorption is observed. A slight narrowing of the spectra and a larger absorptive net polarization is found at K-band. No out-of-phase echo modulation is observed. Taken together, the recombination kinetics, the frequency dependence of the spin polarization and the absence of an out-of-phase echo signal lead to the assignment of the spectra to the contribution from P+. to the state P+.F-X. The origin of the net polarization and its frequency dependence are discussed in terms of singlet-triplet mixing in the precursor. It is shown that the field-dependent polarization expected to develop during the 600-700 ps lifetime of P+.A-.0 is in qualitative agreement with the observed spectra. The identity that the acceptor preceding FX and the conflicting evidence from EPR, optical methods and chemical analyses of the samples are discussed.
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Affiliation(s)
- A van der Est
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
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61
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Angiolillo PJ, Vanderkooi JM. The photoexcited triplet state as a probe of chromophore-protein interaction in myoglobin. Biophys J 1998; 75:1491-502. [PMID: 9726951 PMCID: PMC1299824 DOI: 10.1016/s0006-3495(98)74068-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The photoexcited metastable triplet state of Mg(2+)-mesoporphyrin IX (MgMPIX) or Mg(2+)-protoporphyrin IX (MgPPIX) located in the heme pocket of horse myoglobin (Mb) was investigated by optical and electron paramagnetic resonance (EPR) spectroscopy, and its properties were compared with the model complexes, MgMPIX, MgPPIX, and Mg2+ etioporphyrin I (MgETIOI), in noncoordinating and coordinating organic glasses. Zero-field splitting parameters, line shape, and Jahn-Teller distortion in the temperature range of 3.8-110 K are discussed in terms of porphyrin-protein interactions. The triplet line shapes for MgMPIXMb and MGPPIXMb show no temperature-dependent spectral line shape changes suggestive of Jahn-Teller dynamics, and it is concluded that the energy splitting is >> 150 cm-1, suggesting symmetry breaking from the anisotropy of intermal electric fields of the protein, and consistent with previous predictions (Geissinger et al. 1995. J. Phys. Chem. 99:16527-16529). Both MgMPIXMb and MgPPIXMb demonstrate electron spin polarization at low temperature, and from the polarization pattern it can be concluded that intersystem crossing occurs predominantly into in-plane spin sublevels of the triplet state. The splitting in the Q0.0 absorption band and the temperature dependence and splitting of the photoexcited triplet state of myoglobin in which the iron was replaced by Mg2+ are interpreted in terms of effects produced by electric field asymmetry in the heme pocket.
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Affiliation(s)
- P J Angiolillo
- Department of Physics, Mathematics and Computer Science, University of the Sciences in Philadelphia, Pennsylvania 19104-4495, USA.
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62
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Laible PD, Chynwat V, Thurnauer MC, Schiffer M, Hanson DK, Frank HA. Protein modifications affecting triplet energy transfer in bacterial photosynthetic reaction centers. Biophys J 1998; 74:2623-37. [PMID: 9591686 PMCID: PMC1299602 DOI: 10.1016/s0006-3495(98)77968-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The efficiency of triplet energy transfer from the special pair (P) to the carotenoid (C) in photosynthetic reaction centers (RCs) from a large family of mutant strains has been investigated. The mutants carry substitutions at positions L181 and/or M208 near chlorophyll-based cofactors on the inactive and active sides of the complex, respectively. Light-modulated electron paramagnetic resonance at 10 K, where triplet energy transfer is thermally prohibited, reveals that the mutations do not perturb the electronic distribution of P. At temperatures > or = 70 K, we observe reduced signals from the carotenoid in most of the RCs with L181 substitutions. In particular, triplet transfer efficiency is reduced in all RCs in which a lysine at L181 donates a sixth ligand to the monomeric bacteriochlorophyll B(B). Replacement of the native Tyr at M208 on the active side of the complex with several polar residues increased transfer efficiency. The difference in the efficiencies of transfer in the RCs demonstrates the ability of the protein environment to influence the electronic overlap of the chromophores and thus the thermal barrier for triplet energy transfer.
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Affiliation(s)
- P D Laible
- Center for Mechanistic Biology and Biotechnology and Chemistry Division, Argonne National Laboratory, Illinois 60439, USA.
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63
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Kennis JT, Shkuropatov AY, van Stokkum IH, Gast P, Hoff AJ, Shuvalov VA, Aartsma TJ. Formation of a long-lived P+BA- state in plant pheophytin-exchanged reaction centers of Rhodobacter sphaeroides R26 at low temperature. Biochemistry 1997; 36:16231-8. [PMID: 9405057 DOI: 10.1021/bi9712605] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Femtosecond transient absorption spectroscopy in the range of 500-1040 nm was used to study electron transfer at 5 K in reaction centers of Rhodobacter sphaeroides R26 in which the bacteriopheophytins (BPhe) were replaced by plant pheophytin a (Phe). Primary charge separation took place with a time constant of 1.6 ps, similar to that found in native RCs. Spectral changes around 1020 nm indicated the formation of reduced bacteriochlorophyll (BChl) with the same time constant, and its subsequent decay in 620 ps. This observation identifies the accessory BChl as the primary electron acceptor. No evidence was found for electron transfer to Phe, indicating that electron transfer from BA- occurs directly to the quinone (QA) through superexchange. The results are explained by a model in which the free energy level of P+Phe- lies above that of P+BA-, which itself is below P*. Assuming that the pigment exchange does not affect the energy levels of P* and P+BA-, our results strongly support a two-step model for primary electron transfer in the native bacterial RC, with no, or very little, admixture of superexchange.
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Affiliation(s)
- J T Kennis
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA, Leiden, The Netherlands
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64
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Bratt PJ, Rohrer M, Krzystek J, Evans MCW, Brunel LC, Angerhofer A. Submillimeter High-Field EPR Studies of the Primary Donor in Plant Photosystem I P700•+. J Phys Chem B 1997. [DOI: 10.1021/jp9725238] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter J. Bratt
- The Department of Chemistry, The University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200, Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, and The Department of Biology, Darwin Building, University College London, Gower Street, London WC1H 9EW, United Kingdom
| | - Martin Rohrer
- The Department of Chemistry, The University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200, Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, and The Department of Biology, Darwin Building, University College London, Gower Street, London WC1H 9EW, United Kingdom
| | - J. Krzystek
- The Department of Chemistry, The University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200, Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, and The Department of Biology, Darwin Building, University College London, Gower Street, London WC1H 9EW, United Kingdom
| | - Michael C. W. Evans
- The Department of Chemistry, The University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200, Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, and The Department of Biology, Darwin Building, University College London, Gower Street, London WC1H 9EW, United Kingdom
| | - Louis-Claude Brunel
- The Department of Chemistry, The University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200, Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, and The Department of Biology, Darwin Building, University College London, Gower Street, London WC1H 9EW, United Kingdom
| | - Alexander Angerhofer
- The Department of Chemistry, The University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200, Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, and The Department of Biology, Darwin Building, University College London, Gower Street, London WC1H 9EW, United Kingdom
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65
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Stehlik D, Möbius K. NEW EPR METHODS FOR INVESTIGATING PHOTOPROCESSES WITH PARAMAGNETIC INTERMEDIATES. Annu Rev Phys Chem 1997; 48:745-84. [PMID: 15012455 DOI: 10.1146/annurev.physchem.48.1.745] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
▪ Abstract Some of the significant advances in time-resolved multifrequency electron paramagnetic resonance (EPR) methods are reviewed, with the explicit focus on studies of light-driven processes and photoreactions in real time. Prominent examples are excited state electron transfer reactions with transient charge-separated radical pairs playing a central role. Paramagnetic intermediates and products are key functional states; thus EPR is the method of choice for their characterization. Photogenerated spin polarization and coherences as process-inherent features add the practical advantage of compensation in the trade-off between sensitivity and time resolution. Additionally, they provide detailed structural and dynamic information on the photoreactive system. Significance and specificity of the results achieved for charge separation in photosynthetic reaction centers and donor-acceptor model complexes indicate highly promising perspectives in photochemical research.
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Affiliation(s)
- D Stehlik
- Department of Physics, Free University Berlin, Arnimallee 14, D-14195 Berlin, Germany.
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66
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Franken EM, Shkuropatov AY, Francke C, Neerken S, Gast P, Shuvalov VA, Hoff AJ, Aartsma TJ. Reaction centers of Rhodobacter sphaeroides R-26 with selective replacement of bacteriopheophytin a by pheophytin a. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1997. [DOI: 10.1016/s0005-2728(97)00039-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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67
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Levanon H, Möbius K. Advanced EPR spectroscopy on electron transfer processes in photosynthesis and biomimetic model systems. ANNUAL REVIEW OF BIOPHYSICS AND BIOMOLECULAR STRUCTURE 1997; 26:495-540. [PMID: 9241428 DOI: 10.1146/annurev.biophys.26.1.495] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This review focuses on the recent advances in EPR spectroscopy as they are applied both to photoinduced electron transfer in the photosynthetic apparatus and to biomimetic systems. The review deals with time-resolved direct-detection cw and pulsed EPR and ENDOR methods, both at conventional bands [X-(9.5 GHz), K-(24 GHz), and Q-(35 GHz)(] and at high frequency bands (W-band, 95 GHz, and even higher frequency bands). EPR studies on photosynthetic and model systems in their doublet, triplet and radical pair states are surveyed, including their static and dynamic properties. APplications of time-resolved EPR in studying photoinduced electron and energy transfer in isotropic and anisotropic environments, and the concepts of electron spin polarization and magnetic field effects in photochemical reactions are also reviewed.
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Affiliation(s)
- H Levanon
- Department of Physical Chemistry, Hebrew University of Jerusalem, Israel
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68
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Proskuryakov I, Klenina I, Hore P, Bosch M, Gast P, Hoff A. Electron paramagnetic resonance of the primary radical pair [D·+φA·−] in reaction centers of photosynthetic bacteria. Chem Phys Lett 1996. [DOI: 10.1016/0009-2614(96)00529-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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69
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Nugent JH. Oxygenic photosynthesis. Electron transfer in photosystem I and photosystem II. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 237:519-31. [PMID: 8647094 DOI: 10.1111/j.1432-1033.1996.00519.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Photosystems I and II drive oxygenic photosynthesis. This requires biochemical systems with remarkable properties, allowing these membrane-bound pigment-protein complexes to oxidise water and produce NAD(P)H. The protein environment provides a scaffold in the membrane on which cofactors are placed at optimum distance and orientation, ensuring a rapid, efficient trapping and conversion of light energy. The polypeptide core also tunes the redox potentials of cofactors and provides for unidirectional progress of various reaction steps. The electron transfer pathways use a variety of inorganic and organic cofactors, including amino acids. This review sets out some of the current ideas and data on the cofactors and polypeptides of photosystems I and II.
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Affiliation(s)
- J H Nugent
- Department of Biology, University College London, UK
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Bosch MK, Proskuryakov II, Gast P, Hoff AJ. Time-Resolved EPR Study of the Primary Donor Triplet in D1-D2-cyt b559 Complexes of Photosystem II: Temperature Dependence of Spin−Lattice Relaxation. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp951334r] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martin K. Bosch
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
| | - Ivan I. Proskuryakov
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
| | - Peter Gast
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
| | - Arnold J. Hoff
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
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71
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Di Valentin M, Kay C, Giacometti G, Möbius K. A time-resolved electron nuclear double resonance study of the photoexcited triplet state of P680 in isolated reaction centers of photosystem II. Chem Phys Lett 1996. [DOI: 10.1016/0009-2614(95)01347-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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72
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73
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Angiolillo PJ, Vanderkooi JM. Electron paramagnetic resonance of the excited triplet state of metal-free and metal-substituted cytochrome c. Biophys J 1995; 68:2505-18. [PMID: 7647253 PMCID: PMC1282160 DOI: 10.1016/s0006-3495(95)80433-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The photoactivated metastable triplate states of the porphyrin (free-base, i.e., metal-free) zinc and tin derivatives of horse cytochrome c were investigated using electron paramagnetic resonance. Zero-field splitting parameters, line shape, and Jahn-Teller distortion in the temperature range 3.8-150 K are discussed in terms of porphyrin-protein interactions. The zero-field splitting parameters D for the free-base, Zn and Sn derivatives are 465 x 10(-4), 342 x 10(-4) and 353 x 10(-4) cm-1, respectively, and are temperature invariant over the temperature ranges studied. AN E value at 4 K of 73 x 10(-4) cm-1 was obtained for Zn cytochrome c, larger than any previously found for Zn porphyrins derivatives of hemeproteins, showing that the heme site of cytochrome c imposes an asymmetric field. Though the E value for Zn cytochrome c is large, the geometry of the site appears quite constrained, as indicated by a spectral line shape showing a single species. Intersystem crossing occurred predominantly to the T2 > zero-field spin sublevel. EPR line shape changes with respect to temperature of Zn cyt c are interpreted in terms of vibronic coupling, and a maximum Jahn-Teller crystal-field splitting of approximately 180 cm-1 is obtained. Sn cytochrome c in comparison with the Zn protein exhibits a photoactivated triplet line shape that is less well resolved in the X-Y region. The magnitude of E value is approximately 60 x 10(-4) cm-1 at 4 K; its value rapidly tends toward zero with increasing temperature, from which a value for the Jahn-Teller crystal-field splitting of > or = 40 cm-1 is estimated. In contrast to those for the metal cytochromes, the magnitude of E value for the free-base derivative was essentially zero at all temperatures studied. This finding is discussed as a consequence of an excited-state tautomerization process that occurs even at 4 K.
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Affiliation(s)
- P J Angiolillo
- Johnson Research Foundation, Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia 19104, USA
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74
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Vrieze J, Hoff A. The orientation of the triplet axes with respect to the optical transition moments in (bacterio) chlorophylls. Chem Phys Lett 1995. [DOI: 10.1016/0009-2614(95)00354-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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75
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Klein MP. Perspectives on magnetic resonance and X-ray absorption spectroscopy in biochemistry. Methods Enzymol 1995; 246:529-36. [PMID: 7752936 DOI: 10.1016/0076-6879(95)46023-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- M P Klein
- Lawrence Berkeley Laboratory, University of California, Berkeley 94720, USA
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76
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Proskuryakov II, Shkuropatova VA, Zvereva MG, Shuvalov VA. Formation of charge separated state P+OA- and triplet state 3P at low temperature in Rhodobacter sphaeroides (R-26) reaction centers in which bacteriopheophytin a is replaced by plant pheophytin a. FEBS Lett 1994; 351:249-52. [PMID: 8082774 DOI: 10.1016/0014-5793(94)00843-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Low temperature optical and photochemical properties of Rhodobacter sphaeroides (R-26) reaction centers, in which bacteriopheophytin a has been replaced by plant pheophytin a, are reported. Modified reaction centers preserve the ability for photoinduced electron transfer from the primary electron donor P to the primary quinone acceptor QA at 80K. The triplet state ESR signal of modified reaction centers with prereduced QA at 10K shows an electron spin polarization pattern and ZFS parameters analogous to those for the triplet state 3P in non-treated reaction centers. It was found that at low temperature both P+QA- and 3P states are formed via a precursor radical pair P+I- in which I is the introduced plant pheophytin molecule. This shows that acceptor systems of bacterial and plant (photosystem II) reaction centers are mutually replacable in structural and functional aspects.
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77
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Angerhofer A, Aust V. A monomeric bacteriochlorophyll triplet state (3B) in reaction centres of Rhodobacter sphaeroides R26, studied by absorption-detected magnetic resonance. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1993. [DOI: 10.1016/1011-1344(93)80141-u] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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78
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Frank HA, Innes J, Aldema M, Neumann R, Schenck CC. Triplet state EPR of reaction centers from the His(L173)→Leu (L173) mutant of Rhodobacter sphaeroides which contains a heterodimer primary donor. PHOTOSYNTHESIS RESEARCH 1993; 38:99-109. [PMID: 24317835 DOI: 10.1007/bf00015066] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/1993] [Accepted: 08/11/1993] [Indexed: 06/02/2023]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy has been used to examine the triplet states in reaction centers of Rhodobacter sphaeroides which have undergone a genetic modification affecting the primary donor. Reaction centers containing the His(L173)→Leu(L173) substitution in the amino acid sequence have a primary donor which consists of a BChl-BPh heterodimer. The triplets formed in this heterodimer reaction center were compared with those formed in the wild-type reaction center which contains the BChl-BChl homodimer. Both reaction centers transfer triplet energy to the carotenoid under illumination at liquid nitrogen temperatures (∼90 K). However, the intensity of the carotenoid triplet signal is significantly decreased in the Leu(L173) mutant compared with the wild-type reaction center. At 12 K, in wild-type reaction centers only the primary donor triplet is observed. The Leu(L173) mutant exhibits a signal similar to that observed by Bylina et al. (1990) in His(M200)→Leu(M200) mutant reaction centers from Rb. capsulatus. The values of the zero-field splitting parameters of this triplet are discussed within the context of various models for the primary donor triplet state. No alteration in the ability of the carotenoid to quench the primary donor triplet state results from mutations at these sites.
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Affiliation(s)
- H A Frank
- Department of Chemistry, University of Connecticut, 06269-3060, Storrs, CT, USA
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79
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80
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Tkachenko NV, Grandell D, Ikonen M, Jutila A, Moritz V, Lemmetylnen H. PHOTOPHYSICAL PROPERTIES OF CHLOROPHYLL a LANGMUIR-BLODGETT MULTILAYER FILMS. Photochem Photobiol 1993. [DOI: 10.1111/j.1751-1097.1993.tb09563.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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81
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Davis IH, Heathcote P, MacLachlan DJ, Evans MC. Modulation analysis of the electron spin echo signals of in vivo oxidised primary donor 14N chlorophyll centres in bacterial, P870 and P960, and plant Photosystem I, P700, reaction centres. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1993. [DOI: 10.1016/0005-2728(93)90141-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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82
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Sieckmann I, Brettel K, Bock C, van der Est A, Stehlik D. Transient electron paramagnetic resonance of the triplet state of P700 in photosystem I: evidence for triplet delocalization at room temperature. Biochemistry 1993; 32:4842-7. [PMID: 8387818 DOI: 10.1021/bi00069a020] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Spin-polarized EPR spectra of the triplet state of P700, the primary electron donor in photosystem I (PS I), have been measured for the first time at room temperature. The measurements were performed on intact PS I from Synechococcus sp. after prereduction of all iron-sulfur centers and on vitamin K1 depleted PS I from Synechocystis 6803. The two preparations give similar spectra with a polarization pattern which indicates that the triplet state is formed via recombination of a radical pair. The axial and nonaxial zero-field splitting (zfs) parameters are found to be magnitude of D = (284 +/- 15) x 10(-4) cm-1 and magnitude of E = (22 +/- 3) x 10(-4) cm-1, respectively. The E-value is 42% smaller than in monomeric chlorophyll a, while the D-value is nearly the same. Measurements of the Synechocystis 6803 sample at 4.5 K yielded zfs parameters which are identical with those of the chlorophyll monomer, in agreement with previous results. In order to explain this behavior, it is proposed that the triplet excitation is delocalized over the two halves of a chlorophyll dimer at room temperature but appears localized on one half at low temperature. The observed zfs parameters are obtained if (1) the magnetic z-axes of the two chlorophylls are collinear, (2) the magnetic y-axes (and x-axes) of the two chlorophylls make an angle of approximately 55 degrees with each other, and (3) the admixture of charge-transfer states to 3P700 is negligible.(ABSTRACT TRUNCATED AT 250 WORDS)
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83
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Vass I, Styring S. Characterization of chlorophyll triplet promoting states in photosystem II sequentially induced during photoinhibition. Biochemistry 1993; 32:3334-41. [PMID: 8384878 DOI: 10.1021/bi00064a016] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
It has recently been demonstrated that strong illumination under anaerobic conditions leads to the double reduction of the primary quinone acceptor, QA, which in turn promotes the light-induced formation of triplet reaction center chlorophyll, 3P680, a potentially dangerous species to its protein surroundings in the presence of oxygen [Vass, I., Styring, S., Hundal, T., Koivuniemi, A., Aro, E.-M., & Anderson, B. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 1408-1412]. Here we have studied in further detail the formation of 3P680 producing centers in anaerobically photoinhibited photosystem II membranes by using low-temperature EPR spectroscopy. The results show that 3P680 formation occurs in three different populations of modified photosystem II centers. After a short period of photoinhibitory illumination, a very stable form of singly reduced QA is observed, with a decay halftime of several minutes at room temperature, and our results indicate that already this population of centers promotes the light-induced formation of the spin-polarized EPR signal from 3P680. The formation of these centers is enhanced below pH 6.0, indicating the involvement of a protonation event in neutralizing the negative charge on QA-, a prerequisite for efficient primary charge separation and subsequent triplet formation via the radical pair mechanism. If these centers are incubated in the dark, the stable singly reduced QA species is slowly reoxidized concomitant with the loss of its triplet forming ability. Extended photoinhibitory illumination converts the stable form of singly reduced QA to an EPR-silent species indicating the second reduction of QA-. The second negative charge on the double-reduced QA is neutralized most likely by a second protonation.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- I Vass
- Department of Biochemistry, Arrhenius Laboratories for Natural Sciences, University of Stockholm, Sweden
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84
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Angerhofer A, Bernlochner D, Robert B. Absorption Detected Magnetic Resonance of D1/D2-Complexes from Pisum sativum*. ACTA ACUST UNITED AC 1993. [DOI: 10.1524/zpch.1993.182.part_1_2.167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- A. Angerhofer
- 3. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | - D. Bernlochner
- 3. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | - B. Robert
- Départment de Biologie, CEN-Saclay, F-91191 Gif-Sur-Yvette, France
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86
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Gamliel D, Levanon H. Electron paramagnetic resonance line shapes of photoexcited triplets with rotational diffusion. J Chem Phys 1992. [DOI: 10.1063/1.463539] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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87
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Searle GF, Schaafsma TJ. Fluorescence detected magnetic resonance of the primary donor and inner core antenna chlorophyll in Photosystem I reaction centre protein: Sign inversion and energy transfer. PHOTOSYNTHESIS RESEARCH 1992; 32:193-206. [PMID: 24408360 DOI: 10.1007/bf00034795] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/1992] [Accepted: 03/24/1992] [Indexed: 05/28/2023]
Abstract
The Photosystem I reaction centre protein CP1, isolated from barley using polyacrylamide gel electrophoresis showed an EPR (Electron Paramgnetic Resonance) spectrum with the polarisation pattern AEEAAE, typical of the primary donor triplet state (3)P700, created via radical pair formation and recombination. (3)P700 could also be detected by Fluorescence Detected Magnetic Resonance (FDMR) at λf > 700 nm even in the presence of a large number of chlorophyll antennae. Its zero field splitting parameters, D=282.5×10(-4) cm(-1) and E=38.5×10(-4) cm(-1), were independent of the detection wavelength, and agreed with ADMR (Absorption Detected Magnetic Resonance) and EPR values. The signs of the (3)P700 D+E and D-E transitions were positive (increase in fluorescence intensity on applying a resonance microwave field). In contrast, in the emission band 685 < λf < 700 nm FDMR spectra with negative D+E and D-E transitions were detected, and the D value was wavelength-dependent. These FDMR results support an excitation energy transfer model for CP1, derived from time-resolved fluorescence studies, in which two chlorophyll antenna forms are distinguished, with fluorescence at 685 < λf < 700 nm (inner core antennae, F690), and λf > 700 nm (low energy antenna sites, F720), in addition to the P700. The FDMR spectrum in F690 emission can be interpreted as that of (3)P700, observed via reverse singlet excitation energy transfer and added to the FDMR spectrum of the antenna triplet states generated via intramolecular intersystem crossing. This would indicate that reversible energy transfer between F690 and P700 occurs even at 4.2 K.
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Affiliation(s)
- G F Searle
- Department of Molecular Physics, Agricultural University, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
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