1
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Kandrashkin YE, van der Est A. A two-site triplet exciton hopping model: Application to 3P 700. J Chem Phys 2022; 157:224109. [PMID: 36546793 DOI: 10.1063/5.0132157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
A model is presented describing the effect on spin-polarized transient EPR signals caused by incoherent state hopping between two sites. It is shown that the size of the spin state space can be reduced by half to the subspace described by the site-average Hamiltonian and that the dynamics of the system results in a redistribution of the population between its eigenstates. Analytical expressions for the rates of population redistribution and the line shape are derived for the general case in which the back-and-forth rates are unequal. The EPR signals calculated using these expressions are in very good agreement with those obtained by direct numerical solution of the density matrix rate equations. The model is then used to investigate the influence of exciton hopping on triplet state transient EPR spectra. Using the triplet state of the primary donor of Photosystem I as an example, it is shown that the influence of unequal hopping rates becomes more pronounced in the spectrum at longer delay times after the laser flash.
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Affiliation(s)
- Yuri E Kandrashkin
- Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of RAS, Sibirsky Tract 10/7, Kazan 420029, Russia
| | - Art van der Est
- Department of Chemistry, Brock University, St. Catharines, Ontario L2S 3A1, Canada
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2
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Niklas J, Agostini A, Carbonera D, Di Valentin M, Lubitz W. Primary donor triplet states of Photosystem I and II studied by Q-band pulse ENDOR spectroscopy. PHOTOSYNTHESIS RESEARCH 2022; 152:213-234. [PMID: 35290567 PMCID: PMC9424170 DOI: 10.1007/s11120-022-00905-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/14/2022] [Indexed: 05/05/2023]
Abstract
The photoexcited triplet state of the "primary donors" in the two photosystems of oxygenic photosynthesis has been investigated by means of electron-nuclear double resonance (ENDOR) at Q-band (34 GHz). The data obtained represent the first set of 1H hyperfine coupling tensors of the 3P700 triplet state in PSI and expand the existing data set for 3P680. We achieved an extensive assignment of the observed electron-nuclear hyperfine coupling constants (hfcs) corresponding to the methine α-protons and the methyl group β-protons of the chlorophyll (Chl) macrocycle. The data clearly confirm that in both photosystems the primary donor triplet is located on one specific monomeric Chl at cryogenic temperature. In comparison to previous transient ENDOR and pulse ENDOR experiments at standard X-band (9-10 GHz), the pulse Q-band ENDOR spectra demonstrate both improved signal-to-noise ratio and increased resolution. The observed ENDOR spectra for 3P700 and 3P680 differ in terms of the intensity loss of lines from specific methyl group protons, which is explained by hindered methyl group rotation produced by binding site effects. Contact analysis of the methyl groups in the PSI crystal structure in combination with the ENDOR analysis of 3P700 suggests that the triplet is located on the Chl a' (PA) in PSI. The results also provide additional evidence for the localization of 3P680 on the accessory ChlD1 in PSII.
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Affiliation(s)
- Jens Niklas
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave., Lemont, IL, 60439, USA.
| | - Alessandro Agostini
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy
- Biology Centre, Institute of Plant Molecular Biology, Czech Academy of Sciences, Branišovská 31, 370 05, Ceske Budejovice, Czech Republic
| | - Donatella Carbonera
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy
| | - Marilena Di Valentin
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy.
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.
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3
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Mathis P, Sage E, Byrdin M. Pushing the limits of flash photolysis to unravel the secrets of biological electron and proton transfer. Photochem Photobiol Sci 2022; 21:1533-1544. [DOI: 10.1007/s43630-021-00134-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2021] [Indexed: 11/25/2022]
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4
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Kandrashkin YE, Di Valentin M, van der Est A. Reversible triplet energy hopping in photo-excited molecules: A two-site model for the spin polarization. J Chem Phys 2020; 153:094304. [PMID: 32891093 DOI: 10.1063/5.0022164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The effect of reversible energy hopping between different local environments on the properties of spin-polarized excited states is investigated theoretically using a two-site model. The kinetic equations for the populations of the spin sublevels of the excited state are derived and then used to obtain analytical expressions for the evolution of the spin polarization of excited triplet states under specific conditions. The time dependence of the triplet state polarization patterns is also obtained by numerical solution of the kinetic equations. It is shown that the reversible energy hopping can lead to significant changes in the properties of the triplet state, including changes in the shape of the observed spectrum and, in some cases, the inversion of the sign of the polarization, the generation of the net polarization, and anisotropic spin-lattice relaxation. The relations between the parameters that can be observed experimentally by time-resolved electron paramagnetic resonance spectroscopy and the kinetic and dynamic parameters of the system are discussed.
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Affiliation(s)
- Yuri E Kandrashkin
- Zavoisky Physical-Technical Institute FRC Kazan Scientific Center of RAS, Sibirsky Tract 10/7, Kazan 420029, Russia
| | - Marilena Di Valentin
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Art van der Est
- Department of Chemistry Brock University, St. Catharines, Ontario L2S 3A1, Canada
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5
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Agarwala N, Makita H, Luo L, Xu W, Hastings G. Reversible inhibition and reactivation of electron transfer in photosystem I. PHOTOSYNTHESIS RESEARCH 2020; 145:97-109. [PMID: 32447611 DOI: 10.1007/s11120-020-00760-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
In photosystem I (PSI) complexes at room temperature electron transfer from A1- to FX is an order of magnitude faster on the B-branch compared to the A-branch. One factor that might contribute to this branch asymmetry in time constants is TrpB673 (Thermosynechococcus elongatus numbering), which is located between A1B and FX. The corresponding residue on the A-branch, between A1A and FX, is GlyA693. Here, microsecond time-resolved step-scan FTIR difference spectroscopy at 77 K has been used to study isolated PSI complexes from wild type and TrpB673Phe mutant (WB673F mutant) cells from Synechocystis sp. PCC 6803. WB673F mutant cells require glucose for growth and are light sensitive. Photoaccumulated FTIR difference spectra indicate changes in amide I and II protein vibrations upon mutation of TrpB673 to Phe, indicating the protein environment near FX is altered upon mutation. In the WB673F mutant PSI samples, but not in WT PSI samples, the phylloquinone molecule that occupies the A1 binding site is likely doubly protonated following long periods of repetitive flash illumination at room temperature. PSI with (doubly) protonated quinone in the A1 binding site are not functional in electron transfer. However, electron transfer functionality can be restored by incubating the light-treated mutant PSI samples in the presence of added phylloquinone.
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Affiliation(s)
- Neva Agarwala
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA
| | - Hiroki Makita
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA
| | - Lujun Luo
- Department of Chemistry, University of Louisiana At Lafayette, Lafayette, LA, 70503, USA
| | - Wu Xu
- Department of Chemistry, University of Louisiana At Lafayette, Lafayette, LA, 70503, USA
| | - Gary Hastings
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA.
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6
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Mutations in algal and cyanobacterial Photosystem I that independently affect the yield of initial charge separation in the two electron transfer cofactor branches. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:42-55. [DOI: 10.1016/j.bbabio.2017.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 10/16/2017] [Accepted: 10/17/2017] [Indexed: 01/02/2023]
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7
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Richert S, Tait CE, Timmel CR. Delocalisation of photoexcited triplet states probed by transient EPR and hyperfine spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 280:103-116. [PMID: 28579096 DOI: 10.1016/j.jmr.2017.01.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 01/05/2017] [Accepted: 01/07/2017] [Indexed: 05/22/2023]
Abstract
Photoexcited triplet states play a crucial role in photochemical mechanisms: long known to be of paramount importance in the study of photosynthetic reaction centres, they have more recently also been shown to play a major role in a number of applications in the field of molecular electronics. Their characterisation is crucial for an improved understanding of these processes with a particular focus on the determination of the spatial distribution of the triplet state wavefunction providing information on charge and energy transfer efficiencies. Currently, active research in this field is mostly focussed on the investigation of materials for organic photovoltaics (OPVs) and organic light emitting diodes (OLEDs). As the properties of triplet states and their spatial extent are known to have a major impact on device performance, a detailed understanding of the factors governing triplet state delocalisation is at the basis of the further development and improvement of these devices. Electron Paramagnetic Resonance (EPR) has proven a valuable tool in the study of triplet state properties and both experimental methods as well as data analysis and interpretation techniques have continuously improved over the last few decades. In this review, we discuss the theoretical and practical aspects of the investigation of triplet states and triplet state delocalisation by transient continuous wave and pulse EPR and highlight the advantages and limitations of the presently available techniques and the current trends in the field. Application of EPR in the study of triplet state delocalisation is illustrated on the example of linear multi-porphyrin chains designed as molecular wires.
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Affiliation(s)
- Sabine Richert
- Centre for Advanced Electron Spin Resonance (CAESR), Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom.
| | - Claudia E Tait
- Department of Chemistry, University of Washington, Seattle, WA 98195, United States.
| | - Christiane R Timmel
- Centre for Advanced Electron Spin Resonance (CAESR), Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom.
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8
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Shelaev I, Gorka M, Savitsky A, Kurashov V, Mamedov M, Gostev F, Möbius K, Nadtochenko V, Golbeck J, Semenov A. Effect of Dehydrated Trehalose Matrix on the Kinetics of Forward Electron Transfer Reactions in Photosystem I. ACTA ACUST UNITED AC 2016. [DOI: 10.1515/zpch-2016-0860] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
The effect of dehydration on the kinetics of forward electron transfer (ET) has been studied in cyanobacterial photosystem I (PS I) complexes in a trehalose glassy matrix by time-resolved optical and EPR spectroscopies in the 100 fs to 1 ms time domain. The kinetics of the flash-induced absorption changes in the subnanosecond time domain due to primary and secondary charge separation steps were monitored by pump–probe laser spectroscopy with 20-fs low-energy pump pulses centered at 720 nm. The back-reaction kinetics of P700 were measured by high-field time-resolved EPR spectroscopy and the forward kinetics of
A
1A
•
−
/
A
1
B
•
−
→
F
X
${\rm{A}}_{{\rm{1A}}}^{ \bullet - }/{\rm{A}}_{1{\rm{B}}}^{ \bullet - } \to {{\rm{F}}_{\rm{X}}}$
by time-resolved optical spectroscopy at 480 nm. The kinetics of the primary ET reactions to form the primary
P
700
•
+
A
0
•
−
${\rm{P}}_{700}^{ \bullet + }{\rm{A}}_0^{ \bullet - }$
and the secondary
P
700
•
+
A
1
•
−
${\rm{P}}_{700}^{ \bullet + }{\rm{A}}_1^{ \bullet - }$
ion radical pairs were not affected by dehydration in the trehalose matrix, while the yield of the
P
700
•
+
A
1
•
−
${\rm{P}}_{700}^{ \bullet + }{\rm{A}}_1^{ \bullet - }$
was decreased by ~20%. Forward ET from the phylloquinone molecules in the
A
1
A
•
−
${\rm{A}}_{1{\rm{A}}}^{ \bullet - }$
and
A
1
B
•
−
${\rm{A}}_{1{\rm{B}}}^{ \bullet - }$
sites to the iron–sulfur cluster FX slowed from ~220 ns and ~20 ns in solution to ~13 μs and ~80 ns, respectively. However, as shown by EPR spectroscopy, the ~15 μs kinetic phase also contains a small contribution from the recombination between
A
1
B
•
−
${\rm{A}}_{1{\rm{B}}}^{ \bullet - }$
and
P
700
•
+
.
${\rm{P}}_{700}^{ \bullet + }.$
These data reveal that the initial ET reactions from P700 to secondary phylloquinone acceptors in the A- and B-branches of cofactors (A1A and A1B) remain unaffected whereas ET beyond A1A and A1B is slowed or prevented by constrained protein dynamics due to the dry trehalose glass matrix.
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Affiliation(s)
- Ivan Shelaev
- N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, 119991 Moscow, Russian Federation
| | - Michael Gorka
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States of America
| | - Anton Savitsky
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany , Phone: 0049-208-3063555, Fax: 0049-208-3063955
| | - Vasily Kurashov
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States of America
| | - Mahir Mamedov
- A.N. Belozersky Institute of Physical–Chemical Biology, Moscow State University, Moscow, Leninskie Gory, Moscow 119992, Russian Federation
| | - Fedor Gostev
- N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, 119991 Moscow, Russian Federation
| | - Klaus Möbius
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Victor Nadtochenko
- N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, 119991 Moscow, Russian Federation
| | - John Golbeck
- Department of Biochemistry and Molecular Biology, Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States of America
| | - Alexey Semenov
- N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, 119991 Moscow, Russian Federation
- A.N. Belozersky Institute of Physical–Chemical Biology, Moscow State University, Moscow, Leninskie Gory, Moscow 119992, Russian Federation
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9
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Ferlez B, Agostini A, Carbonera D, Golbeck JH, van der Est A. Triplet Charge Recombination in Heliobacterial Reaction Centers Does Not Produce a Spin-Polarized EPR Spectrum. Z PHYS CHEM 2016. [DOI: 10.1515/zpch-2016-0825] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In photosynthetic reaction centers, reduction of the secondary acceptors leads to triplet charge recombination of the primary radical pair (RP). This process is spin selective and in a magnetic field it populates only the T0 state of the donor triplet state. As a result, the triplet state of the donor has a distinctive spin polarization pattern that can be measured by transient electron paramagnetic resonance (TREPR) spectroscopy. In heliobacterial reaction centers (HbRCs), the primary donor, P800, is composed of two bacteriochlorophyll g′ molecules and its triplet state has not been studied as extensively as those of other reaction centers. Here, we present TREPR and optically detected magnetic resonance (ODMR) data of 3P800 and show that although it can be detected by ODMR it is not observed in the TREPR data. We demonstrate that the absence of the TREPR spectrum is a result of the fact that the zero-field splitting (ZFS) tensor of 3P800 is maximally rhombic, which results in complete cancelation of the absorptive and emissive polarization in randomly oriented samples.
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Affiliation(s)
- Bryan Ferlez
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States of America
| | - Alessandro Agostini
- Dipartimento di Scienze Chimiche, Università di Padova, Via Marzolo, 1, 35131 Padova, Italy
| | - Donatella Carbonera
- Dipartimento di Scienze Chimiche, Università di Padova, Via Marzolo, 1, 35131 Padova, Italy
| | - John H. Golbeck
- Department of Biochemistry and Molecular Biology and Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States of America
- Freiburg Institute of Advanced Studies (FRIAS), Albert-Ludwigs-Universität Freiburg, Albertstr.19, 79104 Freiburg, Germany
| | - Art van der Est
- Freiburg Institute of Advanced Studies (FRIAS), Albert-Ludwigs-Universität Freiburg, Albertstr.19, 79104 Freiburg, Germany
- Departments of Chemistry and Physics, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, Canada L2S 3A1
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10
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Richert S, Peeks MD, Tait CE, Anderson HL, Timmel CR. Photogenerated triplet states in supramolecular porphyrin ladder assemblies: an EPR study. Phys Chem Chem Phys 2016; 18:24171-5. [DOI: 10.1039/c6cp04444a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ladder formation and planarisation do not enhance delocalisation in the triplet excited states of linear porphyrin oligomers.
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Affiliation(s)
- Sabine Richert
- Centre for Advanced Electron Spin Resonance (CAESR)
- University of Oxford
- Oxford
- UK
| | | | - Claudia E. Tait
- Centre for Advanced Electron Spin Resonance (CAESR)
- University of Oxford
- Oxford
- UK
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11
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Evidence that histidine forms a coordination bond to the A0A and A0B chlorophylls and a second H-bond to the A1A and A1B phylloquinones in M688HPsaA and M668HPsaB variants of Synechocystis sp. PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1362-75. [DOI: 10.1016/j.bbabio.2014.04.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 04/02/2014] [Accepted: 04/04/2014] [Indexed: 11/21/2022]
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12
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Kamlowski A, Frankemöller L, van der Est A, Stehlik D, Holzwart AR. Evidence for delocalization of the triplet state 3P680 in the D1D2cytb559-complex of photosystem II. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19961001221] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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13
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Stehli D, van der Est A, Kamlowski A. Transient magnetic resonance. Transient spin states in the primary processes of photosynthesis. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19961001218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Sakuragi Y, Zybailov B, Shen G, Bryant DA, Golbeck JH, Diner BA, Karygina I, Pushkar Y, Stehlik D. Recruitment of a Foreign Quinone into the A1 Site of Photosystem I. J Biol Chem 2005; 280:12371-81. [PMID: 15681848 DOI: 10.1074/jbc.m412943200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A photosystem I (PS I) complex containing plastoquinone-9 (PQ-9) but devoid of F(X), F(B), and F(A) was isolated and characterized from a mutant strain of Synechococcus sp. PCC 7002 in which the menB and rubA genes were insertionally inactivated. In isolated PS I trimers, the decay of P700+ measured in the near-IR and the decay of A1- measured in the near-UV were found to be biphasic, with (averaged) room temperature lifetimes of 12 and 350 micros. The decay-associated spectra of both kinetic phases are characteristic of the oxidized minus reduced difference spectrum of a semiquinone, consistent with charge recombination between P700+ and PQ-9-. The amplitude of the flash-induced absorbance changes in both the near-IR and the near-UV show that approximately one-half of the A1 binding sites are either empty or nonfunctional. A spin-polarized chlorophyll triplet is observed by time-resolved EPR, and it is attributed to the 3P700 product of P700+A0- charge recombination via the T0 spin level in those PS I complexes that do not contain a functional quinone. In those A1 sites that are occupied, the P700+Q- polarization pattern indicates that PQ-9 is oriented in a similar manner to that in the menB mutant. When excess 9,10-anthraquinone is added in vitro, it displaces PQ-9 and occupies the A1 binding site more readily than in the menB mutant. This can be explained by a greater accessibility to the A1 site in the menB rubA mutant due to the absence of F(X) and the stromal ridge polypeptides. The relatively low binding affinity of 9,10-anthraquinone allows it to be readily removed from the A1 site by washing. However, all A1 sites are shown to bind napthoquinones with high affinity and thus are proven to be functionally competent in quinone binding. The ability to readily displace PQ-9 from the A1 site makes the menB rubA mutant ideal for introducing novel quinones, particularly anthraquinones, into PS I.
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Affiliation(s)
- Yumiko Sakuragi
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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15
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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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16
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Yamauchi S, Takahashi A, Iwasaki Y, Unno M, Ohba Y, Higuchi J, Blank A, Levanon H. The Lowest Photoexcited Triplet State of Subphthalocyanine in Solid and Fluid Environments. Time-Resolved Electron Paramagnetic Resonance Studies. J Phys Chem A 2003. [DOI: 10.1021/jp0258210] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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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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18
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Lubitz W, Lendzian F, Bittl R. Radicals, radical pairs and triplet states in photosynthesis. Acc Chem Res 2002; 35:313-20. [PMID: 12020169 DOI: 10.1021/ar000084g] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The investigation of radical ions, radical pairs, and triplet states that occur in the primary processes of photosynthesis by various EPR techniques is described. The determination of the valence electron spin density distribution by ENDOR/TRIPLE spectroscopy is demonstrated for the primary electron donor. In combination with site-directed mutagenesis, these studies show that the spin distribution in the chlorophyll donor is strongly affected by the protein environment, and a link is established with the donor's oxidation potential and function in the electron transfer process. Similarities and differences between electron donors in anoxygenic (bacterial) and oxygenic photosynthesis are briefly discussed. Application of transient and pulse EPR techniques give information also on short-lived intermediates, such as radical pairs and triplet states, and allow the determination of distances and relative orientations of these species. The extension to time-resolved pulse ENDOR spectroscopy opens the possibility to resolve the electron-nuclear hyperfine structure of these reaction intermediates, even on a very short time scale.
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Affiliation(s)
- Wolfgang Lubitz
- Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, 45470 Mülheim/Ruhr, Germany
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Webber AN, Lubitz W. P700: the primary electron donor of photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1507:61-79. [PMID: 11687208 DOI: 10.1016/s0005-2728(01)00198-0] [Citation(s) in RCA: 211] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The primary electron donor of photosystem I, P700, is a chlorophyll species that in its excited state has a potential of approximately -1.2 V. The precise chemical composition and electronic structure of P700 is still unknown. Recent evidence indicates that P700 is a dimer of one chlorophyll (Chl) a and one Chl a'. The Chl a' and Chl a are axially coordinated by His residues provided by protein subunits PsaA and PsaB, respectively. The Chl a', but not the Chl a, is also H-bonded to the protein. The H-bonding is likely responsible for selective insertion of Chl a' into the reaction center. EPR studies of P700(+*) in frozen solution and single crystals indicate a large asymmetry in the electron spin and charge distribution towards one Chl of the dimer. Molecular orbital calculations indicate that H-bonding will specifically stabilize the Chl a'-side of the dimer, suggesting that the unpaired electron would predominantly reside on the Chl a. This is supported by results of specific mutagenesis of the PsaA and PsaB axial His residues, which show that only mutations of the PsaB subunit significantly alter the hyperfine coupling constants associated with a single Chl molecule. The PsaB mutants also alter the microwave induced triplet-minus-singlet spectrum indicating that the triplet state is localized on the same Chl. Excitonic coupling between the two Chl a of P700 is weak due to the distance and overlap of the porphyrin planes. Evidence of excitonic coupling is found in PsaB mutants which show a new bleaching band at 665 nm that likely represents an increased intensity of the upper exciton band of P700. Additional properties of P700 that may give rise to its unusually low potential are discussed.
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Affiliation(s)
- A N Webber
- Department of Plant Biology and Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe 85287-1601, USA.
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Abstract
In plants and cyanobacteria, the primary step in oxygenic photosynthesis, the light induced charge separation, is driven by two large membrane intrinsic protein complexes, the photosystems I and II. Photosystem I catalyses the light driven electron transfer from plastocyanin/cytochrome c(6) on the lumenal side of the membrane to ferredoxin/flavodoxin at the stromal side by a chain of electron carriers. Photosystem I of Synechococcus elongatus consists of 12 protein subunits, 96 chlorophyll a molecules, 22 carotenoids, three [4Fe4S] clusters and two phylloquinones. Furthermore, it has been discovered that four lipids are intrinsic components of photosystem I. Photosystem I exists as a trimer in the native membrane with a molecular mass of 1068 kDa for the whole complex. The X-ray structure of photosystem I at a resolution of 2.5 A shows the location of the individual subunits and cofactors and provides new information on the protein-cofactor interactions. [P. Jordan, P. Fromme, H.T. Witt, O. Klukas, W. Saenger, N. Krauss, Nature 411 (2001) 909-917]. In this review, biochemical data and results of biophysical investigations are discussed with respect to the X-ray crystallographic structure in order to give an overview of the structure and function of this large membrane protein.
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Affiliation(s)
- P Fromme
- Max Volmer Laboratorium für Biophysikalische Chemie Institut für Chemie, Technische Universität Berlin, Germany.
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Käss H, Fromme P, Witt HT, Lubitz W. Orientation and Electronic Structure of the Primary Donor Radical Cation in Photosystem I: A Single Crystals EPR and ENDOR Study. J Phys Chem B 2001. [DOI: 10.1021/jp0032311] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hanno Käss
- Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Str. d. 17. Juni 135, D-10623 Berlin, Germany
| | - Petra Fromme
- Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Str. d. 17. Juni 135, D-10623 Berlin, Germany
| | - Horst T. Witt
- Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Str. d. 17. Juni 135, D-10623 Berlin, Germany
| | - Wolfgang Lubitz
- Max-Volmer-Institut für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Str. d. 17. Juni 135, D-10623 Berlin, Germany
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Kim S, Barry BA. Identification of Carbonyl Modes of P700 and P700+ by in situ Chlorophyll Labeling in Photosystem I†. J Am Chem Soc 2000. [DOI: 10.1021/ja000512d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sunyoung Kim
- University of Minnesota Department of Biochemistry, Molecular Biology, & Biophysics St. Paul, Minnesota 55108-1022
| | - Bridgette A. Barry
- University of Minnesota Department of Biochemistry, Molecular Biology, & Biophysics St. Paul, Minnesota 55108-1022
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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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Carbonera D, Giacometti G, Segre U, Angerhofer A, Gross U. Model for Triplet−Triplet Energy Transfer in Natural Clusters of Peridinin Molecules Contained in Dinoflagellate's Outer Antenna Proteins. J Phys Chem B 1999. [DOI: 10.1021/jp984641g] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Donatella Carbonera
- Dipartimento di Chimica-Fisica, Università di Padova, Via Loredan 2, I-35131 Padova, Italy
| | - Giovanni Giacometti
- Dipartimento di Chimica-Fisica, Università di Padova, Via Loredan 2, I-35131 Padova, Italy
| | - Ulderico Segre
- Dipartimento di Chimica, Università di Modena, Via Campi 183, 41100 Modena, Italy, and CSSMRE CNR, Via Loredan 2, I-35131 Padova, Italy
| | | | - Ulrich Gross
- 3. Physikalisches Institut, Universität Stuttgart, Stuttgart, Germany
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The P700 triplet state in an intact environment detected by ODMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1997. [DOI: 10.1016/s0005-2728(97)00068-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Electron transfer and arrangement of the redox cofactors in photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1997. [DOI: 10.1016/s0005-2728(96)00112-0] [Citation(s) in RCA: 380] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Vrieze J, Gast P, Hoff AJ. Structure of the Reaction Center of Photosystem I of Plants. An Investigation with Linear-Dichroic Absorbance-Detected Magnetic Resonance. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp9524789] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Vrieze
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - P. Gast
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
| | - A. J. Hoff
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
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Nabedryk E, Leibl W, Breton J. FTIR spectroscopy of primary donor photooxidation in Photosystem I, Heliobacillus mobilis, and Chlorobium limicola. Comparison with purple bacteria. PHOTOSYNTHESIS RESEARCH 1996; 48:301-308. [PMID: 24271311 DOI: 10.1007/bf00041021] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/1995] [Accepted: 02/12/1996] [Indexed: 06/02/2023]
Abstract
The photooxidation of the primary electron donor in several Photosystem I-related organisms (Synechocystis sp. PCC 6803, Heliobacillus mobilis, and Chlorobium limicola f. sp. thiosulphatophilum) has been studied by light-induced FTIR difference spectroscopy at 100 K in the 4000 to 1200 cm(-1) spectral range. The data are compared to the well-characterized FTIR difference spectra of the photooxidation of the primary donor P in Rhodobacter sphaeroides (both wild type and the heterodimer mutant HL M202) in order to get information on the charge localization and the extent of coupling within the (bacterio)chlorophylls constituting the oxidized primary donors. In Rb. sphaeroides RC, four marker bands mostly related to the dimeric nature of the oxidized primary donor have been previously observed at ≈2600, 1550, 1480, and 1295 cm(-1). The high-frequency band has been shown to correspond to an electronic transition (Breton et al. (1992) Biochemistry 31: 7503-7510) while the three other marker bands have been described as phase-phonon bands (Reimers and Hush (1995) Chem Phys 197: 323-332). The absence of these bands in PS I as well as in the heterodimer HL M202 demonstrates that in P700(+) the charge is essentially localized on a single chlorophyll molecule. For both H. mobilis and C. limicola, the presence of a high-frequency band at ≈ 2050 and 2450 cm(-1), respectively, and of phase-phonon bands (at ≈ 1535 and 1300 cm(-1) in H. mobilis, at ≈ 1465 and 1280 cm(-1) in C. limicola) indicate that the positive charge in the photooxidized primary donor is shared between two coupled BChls. The structure of P840(+) in C. limicola, in terms of the resonance interactions between the two BChl a molecules constituting the oxidized primary donor, is close to that of P(+) in purple bacteria reaction centers while for H. mobilis the FTIR data are interpreted in terms of a weaker coupling of the two bacteriochlorophylls.
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Affiliation(s)
- E Nabedryk
- Section de Bioénergétique, Departement de Biologie Cellulaire et Moléculaire, CEA/Saclay, 91191, Gif-sur-Yvette Cedex, France
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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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Weber S, Ohmes E, Thurnauer MC, Norris JR, Kothe G. Light-generated nuclear quantum beats: a signature of photosynthesis. Proc Natl Acad Sci U S A 1995; 92:7789-93. [PMID: 11607572 PMCID: PMC41231 DOI: 10.1073/pnas.92.17.7789] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Light-induced radical pairs in deuterated and deuterated plus 15N-substituted Synechococcus lividus cyanobacteria have been studied by transient EPR following pulsed laser excitation. Nuclear quantum beats are observed in the transverse electron magnetization at lower temperatures. Model calculations for the time profiles, evaluated at the high-field emissive maximum of the spectrum, indicate assignment of these coherences to nitrogen nuclei in the primary donor. Thorough investigation of the nuclear modulation patterns can provide detailed information on the electronic structure of the primary donor, providing insight into the mechanism of the primary events of plant photosynthesis.
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Affiliation(s)
- S Weber
- Department of Physical Chemistry, University of Stuttgart, Stuttgart, Germany
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van der Vos R, Hoff AJ. Optically-detected magnetic field effects on the Dl-D2-cyt b-559 complex of Photosystem II. Temperature dependence of kinetics and structure. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1995. [DOI: 10.1016/0005-2728(94)00167-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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