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Kamada S, Nakajima Y, Shen JR. Structural insights into the action mechanisms of artificial electron acceptors in photosystem II. J Biol Chem 2023:104839. [PMID: 37209822 PMCID: PMC10300377 DOI: 10.1016/j.jbc.2023.104839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/07/2023] [Accepted: 05/15/2023] [Indexed: 05/22/2023] Open
Abstract
Photosystem II (PSII) utilizes light energy to split water, and the electrons extracted from water are transferred to QB, a plastoquinone (PQ) molecule bound to the D1 subunit of PSII. Many artificial electron acceptors (AEAs) with similar molecular structures to PQ can accept electrons from PSII. However, the molecular mechanism by which AEAs act on PSII is unclear. Here, we solved the crystal structure of PSII treated with three different AEAs, 2,5-dibromo-1,4-benzoquinone, 2,6-dichloro-1,4-benzoquinone, and 2-phenyl-1,4-benzoquinone, at 1.95-2.10 Å resolution. Our results show that all AEAs substitute for QB and are bound to the QB-binding site (QB site) to receive electrons, but their binding strengths are different, resulting in differences in their efficiencies to accept electrons. The acceptor 2-phenyl-1,4-benzoquinone binds most weakly to the QB site, and showed the highest oxygen-evolving activity, implying a reverse relationship between the binding strength and oxygen-evolving activity. In addition, a novel quinone binding site, designated the QD site, was discovered, which is located in the vicinity of QB site and close to QC site, a binding site reported previously. This QD site is expected to play a role as a channel or a storage site for quinones to be transported to the QB site. These results provide the structural basis for elucidating the actions of AEAs and exchange mechanism of QB in PSII, and also provide information for the design of more efficient electron acceptors.
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Affiliation(s)
- Shinji Kamada
- Faculty of Science, Okayama University, Okayama 700-8503, Japan
| | - Yoshiki Nakajima
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8503, Japan.
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8503, Japan.
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2
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Lambertz J, Meier-Credo J, Kucher S, Bordignon E, Langer JD, Nowaczyk MM. Isolation of a novel heterodimeric PSII complex via strep-tagged PsbO. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148953. [PMID: 36572329 DOI: 10.1016/j.bbabio.2022.148953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 11/28/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022]
Abstract
The multi-subunit membrane protein complex photosystem II (PSII) catalyzes the light-driven oxidation of water and with this the initial step of photosynthetic electron transport in plants, algae, and cyanobacteria. Its biogenesis is coordinated by a network of auxiliary proteins that facilitate the stepwise assembly of individual subunits and cofactors, forming various intermediate complexes until fully functional mature PSII is present at the end of the process. In the current study, we purified PSII complexes from a mutant line of the thermophilic cyanobacterium Thermosynechococcus vestitus BP-1 in which the extrinsic subunit PsbO, characteristic for active PSII, was fused with an N-terminal Twin-Strep-tag. Three distinct PSII complexes were separated by ion-exchange chromatography after the initial affinity purification. Two complexes differ in their oligomeric state (monomeric and dimeric) but share the typical subunit composition of mature PSII. They are characterized by the very high oxygen evolving activity of approx. 6000 μmol O2·(mg Chl·h)-1. Analysis of the third (heterodimeric) PSII complex revealed lower oxygen evolving activity of approx. 3000 μmol O2·(mg Chl·h)-1 and a manganese content of 2.7 (±0.2) per reaction center compared to 3.7 (±0.2) of fully active PSII. Mass spectrometry and time-resolved fluorescence spectroscopy further indicated that PsbO is partially replaced by Psb27 in this PSII fraction, thus implying a role of this complex in PSII repair.
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Affiliation(s)
- Jan Lambertz
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Jakob Meier-Credo
- Proteomics, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany
| | - Svetlana Kucher
- Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Enrica Bordignon
- Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44801 Bochum, Germany; Department of Physical Chemistry, University of Geneva, Quai Ernest Ansermet 30, 1211 Geneva, Switzerland(1)
| | - Julian D Langer
- Proteomics, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany; Proteomics, Max Planck Institute for Brain Research, Max-von-Laue-Str. 4, 60438 Frankfurt am Main, Germany
| | - Marc M Nowaczyk
- Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Universitätsstraße 150, 44801 Bochum, Germany; Department of Biochemistry, University of Rostock, Albert-Einstein-Str. 3, 18059 Rostock, Germany(1).
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3
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Manoj KM, Gideon DA, Parashar A, Nirusimhan V, Annadurai P, Jacob VD, Manekkathodi A. Validating the predictions of murburn model for oxygenic photosynthesis: Analyses of ligand-binding to protein complexes and cross-system comparisons. J Biomol Struct Dyn 2022; 40:11024-11056. [PMID: 34328391 DOI: 10.1080/07391102.2021.1953607] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this second half of our treatise on oxygenic photosynthesis, we provide support for the murburn model of the light reaction of photosynthesis and ratify key predictions made in the first part. Molecular docking and visualization of various ligands of quinones/quinols (and their derivatives) with PS II/Cytochrome b6f complexes did not support chartered 2e-transport role of quinols. A broad variety of herbicides did not show any affinity/binding-based rationales for inhibition of photosynthesis. We substantiate the proposal that disubstituted phenolics (perceived as protonophores/uncouplers or affinity-based inhibitors in the classical purview) serve as interfacial modulators of diffusible reactive (oxygen) species or DR(O)S. The DRS-based murburn model is evidenced by the identification of multiple ADP-binding sites on the extra-membraneous projection of protein complexes and structure/distribution of the photo/redox catalysts. With a panoramic comparison of the redox metabolic machinery across diverse organellar/cellular systems, we highlight the ubiquitous one-electron murburn facets (cofactors of porphyrin, flavin, FeS, other metal centers and photo/redox active pigments) that enable a facile harnessing of the utility of DRS. In the summative analyses, it is demonstrated that the murburn model of light reaction explains the structures of membrane supercomplexes recently observed in thylakoids and also accounts for several photodynamic experimental observations and evolutionary considerations. In toto, the work provides a new orientation and impetus to photosynthesis research. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kelath Murali Manoj
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Daniel Andrew Gideon
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Abhinav Parashar
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Vijay Nirusimhan
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Pushparaj Annadurai
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Vivian David Jacob
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Afsal Manekkathodi
- RedOx Lab, Department of Life Sciences, Satyamjayatu: The Science & Ethics Foundation, Palakkad District, Kerala, India
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Bicarbonate-controlled reduction of oxygen by the Q A semiquinone in Photosystem II in membranes. Proc Natl Acad Sci U S A 2022; 119:2116063119. [PMID: 35115403 PMCID: PMC8833163 DOI: 10.1073/pnas.2116063119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2021] [Indexed: 12/15/2022] Open
Abstract
In Photosystem II (PSII), O2 reduction by QA•− is often discussed but has not been demonstrated. Here, we show in PSII membranes that QA•− can reduce O2 to superoxide, but only when bicarbonate is absent from its binding site on the nonheme Fe2+. Bicarbonate’s role in PSII was recently shown to involve a regulatory/protective redox-tuning mechanism linking PSII function to CO2 concentration. A key aspect is the presence of stable QA•− causing release of bicarbonate from its site on Fe2+. Here, we show that under these conditions, O2 binds to the empty site on the Fe2+ and is reduced by QA•−. This unexpected reaction may be a further indication of cross-talk between the regulation of PSII and CO2 fixation. Photosystem II (PSII), the water/plastoquinone photo-oxidoreductase, plays a key energy input role in the biosphere. QA•−, the reduced semiquinone form of the nonexchangeable quinone, is often considered capable of a side reaction with O2, forming superoxide, but this reaction has not yet been demonstrated experimentally. Here, using chlorophyll fluorescence in plant PSII membranes, we show that O2 does oxidize QA•− at physiological O2 concentrations with a t1/2 of 10 s. Superoxide is formed stoichiometrically, and the reaction kinetics are controlled by the accessibility of O2 to a binding site near QA•−, with an apparent dissociation constant of 70 ± 20 µM. Unexpectedly, QA•− could only reduce O2 when bicarbonate was absent from its binding site on the nonheme iron (Fe2+) and the addition of bicarbonate or formate blocked the O2-dependant decay of QA•−. These results, together with molecular dynamics simulations and hybrid quantum mechanics/molecular mechanics calculations, indicate that electron transfer from QA•− to O2 occurs when the O2 is bound to the empty bicarbonate site on Fe2+. A protective role for bicarbonate in PSII was recently reported, involving long-lived QA•− triggering bicarbonate dissociation from Fe2+ [Brinkert et al., Proc. Natl. Acad. Sci. U.S.A. 113, 12144–12149 (2016)]. The present findings extend this mechanism by showing that bicarbonate release allows O2 to bind to Fe2+ and to oxidize QA•−. This could be beneficial by oxidizing QA•− and by producing superoxide, a chemical signal for the overreduced state of the electron transfer chain.
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Mäusle SM, Abzaliyeva A, Greife P, Simon PS, Perez R, Zilliges Y, Dau H. Activation energies for two steps in the S 2→ S 3 transition of photosynthetic water oxidation from time-resolved single-frequency infrared spectroscopy. J Chem Phys 2020; 153:215101. [PMID: 33291916 DOI: 10.1063/5.0027995] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The mechanism of water oxidation by the Photosystem II (PSII) protein-cofactor complex is of high interest, but specifically, the crucial coupling of protonation dynamics to electron transfer (ET) and dioxygen chemistry remains insufficiently understood. We drove spinach-PSII membranes by nanosecond-laser flashes synchronously through the water-oxidation cycle and traced the PSII processes by time-resolved single-frequency infrared (IR) spectroscopy in the spectral range of symmetric carboxylate vibrations of protein side chains. After the collection of IR-transients from 100 ns to 1 s, we analyzed the proton-removal step in the S2 ⇒ S3 transition, which precedes the ET that oxidizes the Mn4CaOx-cluster. Around 1400 cm-1, pronounced changes in the IR-transients reflect this pre-ET process (∼40 µs at 20 °C) and the ET step (∼300 µs at 20 °C). For transients collected at various temperatures, unconstrained multi-exponential simulations did not provide a coherent set of time constants, but constraining the ET time constants to previously determined values solved the parameter correlation problem and resulted in an exceptionally high activation energy of 540 ± 30 meV for the pre-ET step. We assign the pre-ET step to deprotonation of a group that is re-protonated by accepting a proton from the substrate-water, which binds concurrently with the ET step. The analyzed IR-transients disfavor carboxylic-acid deprotonation in the pre-ET step. Temperature-dependent amplitudes suggest thermal equilibria that determine how strongly the proton-removal step is reflected in the IR-transients. Unexpectedly, the proton-removal step is only weakly reflected in the 1400 cm-1 transients of PSII core complexes of a thermophilic cyanobacterium (T. elongatus).
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Affiliation(s)
- Sarah M Mäusle
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Aiganym Abzaliyeva
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Paul Greife
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Philipp S Simon
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Rebeca Perez
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Yvonne Zilliges
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Holger Dau
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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6
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Zaspa AA, Vitukhnovskaya LA, Mamedova AM, Semenov AY, Mamedov MD. Photovoltage generation by photosystem II core complexes immobilized onto a Millipore filter on an indium tin oxide electrode. J Bioenerg Biomembr 2020; 52:495-504. [PMID: 33190172 DOI: 10.1007/s10863-020-09857-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/28/2020] [Indexed: 10/23/2022]
Abstract
The light-induced functioning of photosynthetic pigment-protein complex of photosystem II (PSII) is linked to the vectorial translocation of charges across the membrane, which results in the formation of voltage. Direct measurement of the light-induced voltage (∆V) generated by spinach oxygen-evolving PSII core complexes adsorbed onto a Millipore membrane filter (MF) on an indium tin oxide (ITO) electrode under continuous illumination has been performed. PSII was shown to participate in electron transfer from water to the ITO electrode, resulting in ∆V generation. No photovoltage was detected in PSII deprived of the water-oxidizing complex. The maximal and stable photoelectric signal was observed in the presence of disaccharide trehalose and 2,6-dichloro-1,4-benzoquinone, acting as a redox mediator between the primary quinone acceptor QA of PSII and electrode surface. Long time preservation of the steady-state photoactivity at room temperature in a simple in design ITO|PSII-MF|ITO system may be related to the retention of water molecules attached to the PSII surface in the presence of trehalose.
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Affiliation(s)
- Andrey A Zaspa
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Liya A Vitukhnovskaya
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - Aida M Mamedova
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,First Moscow State Medical University, Moscow, Russia
| | - Alexey Yu Semenov
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - Mahir D Mamedov
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.
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Ibrahim M, Fransson T, Chatterjee R, Cheah MH, Hussein R, Lassalle L, Sutherlin KD, Young ID, Fuller FD, Gul S, Kim IS, Simon PS, de Lichtenberg C, Chernev P, Bogacz I, Pham CC, Orville AM, Saichek N, Northen T, Batyuk A, Carbajo S, Alonso-Mori R, Tono K, Owada S, Bhowmick A, Bolotovsky R, Mendez D, Moriarty NW, Holton JM, Dobbek H, Brewster AS, Adams PD, Sauter NK, Bergmann U, Zouni A, Messinger J, Kern J, Yachandra VK, Yano J. Untangling the sequence of events during the S 2 → S 3 transition in photosystem II and implications for the water oxidation mechanism. Proc Natl Acad Sci U S A 2020; 117:12624-12635. [PMID: 32434915 PMCID: PMC7293653 DOI: 10.1073/pnas.2000529117] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In oxygenic photosynthesis, light-driven oxidation of water to molecular oxygen is carried out by the oxygen-evolving complex (OEC) in photosystem II (PS II). Recently, we reported the room-temperature structures of PS II in the four (semi)stable S-states, S1, S2, S3, and S0, showing that a water molecule is inserted during the S2 → S3 transition, as a new bridging O(H)-ligand between Mn1 and Ca. To understand the sequence of events leading to the formation of this last stable intermediate state before O2 formation, we recorded diffraction and Mn X-ray emission spectroscopy (XES) data at several time points during the S2 → S3 transition. At the electron acceptor site, changes due to the two-electron redox chemistry at the quinones, QA and QB, are observed. At the donor site, tyrosine YZ and His190 H-bonded to it move by 50 µs after the second flash, and Glu189 moves away from Ca. This is followed by Mn1 and Mn4 moving apart, and the insertion of OX(H) at the open coordination site of Mn1. This water, possibly a ligand of Ca, could be supplied via a "water wheel"-like arrangement of five waters next to the OEC that is connected by a large channel to the bulk solvent. XES spectra show that Mn oxidation (τ of ∼350 µs) during the S2 → S3 transition mirrors the appearance of OX electron density. This indicates that the oxidation state change and the insertion of water as a bridging atom between Mn1 and Ca are highly correlated.
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Affiliation(s)
- Mohamed Ibrahim
- Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany
| | - Thomas Fransson
- Interdisciplinary Center for Scientific Computing, University of Heidelberg, 69120 Heidelberg, Germany
| | - Ruchira Chatterjee
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Mun Hon Cheah
- Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University, SE 75120 Uppsala, Sweden
| | - Rana Hussein
- Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany
| | - Louise Lassalle
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Kyle D Sutherlin
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Iris D Young
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Franklin D Fuller
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025
| | - Sheraz Gul
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - In-Sik Kim
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Philipp S Simon
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Casper de Lichtenberg
- Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University, SE 75120 Uppsala, Sweden
- Institutionen för Kemi, Kemiskt Biologiskt Centrum, Umeå Universitet, SE 90187 Umeå, Sweden
| | - Petko Chernev
- Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University, SE 75120 Uppsala, Sweden
| | - Isabel Bogacz
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Cindy C Pham
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Allen M Orville
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, OX11 0DE Didcot, United Kingdom
- Research Complex at Harwell, Rutherford Appleton Laboratory, OX11 0FA Didcot, United Kingdom
| | - Nicholas Saichek
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Trent Northen
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Alexander Batyuk
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025
| | - Sergio Carbajo
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025
| | - Roberto Alonso-Mori
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute, Sayo-cho, Sayo-gun, 679-5198 Hyogo, Japan
- RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, 679-5148 Hyogo, Japan
| | - Shigeki Owada
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Japan Synchrotron Radiation Research Institute, Sayo-cho, Sayo-gun, 679-5198 Hyogo, Japan
| | - Asmit Bhowmick
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Robert Bolotovsky
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Derek Mendez
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Nigel W Moriarty
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - James M Holton
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158
| | - Holger Dobbek
- Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany
| | - Aaron S Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Paul D Adams
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Department of Bioengineering, University of California, Berkeley, CA 94720
| | - Nicholas K Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Uwe Bergmann
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA 94025
| | - Athina Zouni
- Institut für Biologie, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany;
| | - Johannes Messinger
- Department of Chemistry - Ångström, Molecular Biomimetics, Uppsala University, SE 75120 Uppsala, Sweden;
- Institutionen för Kemi, Kemiskt Biologiskt Centrum, Umeå Universitet, SE 90187 Umeå, Sweden
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Vittal K Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720;
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720;
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Swatch GK, Singh DP, Khattar JS, Mohapatra PK. Interaction of pretilachlor with PS-II activity of the cyanobacterium Desmonostoc muscorum PUPCCC 405.10. J Basic Microbiol 2020; 60:532-542. [PMID: 32159865 DOI: 10.1002/jobm.201900706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/03/2020] [Accepted: 02/26/2020] [Indexed: 11/10/2022]
Abstract
Interaction of pretilachlor with photosystem (PS)-II of the cyanobacterium Desmonostoc muscorum PUPCCC 405.10 has been studied in this paper. Pretilachlor negatively affected growth, chlorophyll a (Chl a), photosynthesis, and carbon dissimilation in a dose-dependent manner. Effects were also observed in PSs, especially PS-II (an 11-35% decrease), as well as the whole photosynthetic electron transport activity. The fluorescence emission spectrum of Chl a revealed a dose-dependent effect of pretilachlor on both the antenna and the core complex of PSs, with more severe effect on the former. Data of O-J-I-P fluorescence transient of Chl a revealed that pretilachlor interfered with electron flow between QA and QB sites of PS-II. It was further observed that pretilachlor decreased maximum fluorescence, variable and relative variable fluorescence, maximum quantum yield, quantum yield of electron transport, the rate of trapped exciton movement, quantum yield of electron transfer, and performance index of primary photochemistry; however, there was a progressive increase in the net rate of PS-II closure, quantum yield of energy dissipation, and effective antenna size per active reaction center. A decrease in photosynthetic activity leads to a decrease in carbon dissimilation, as evidenced by low activity of glucose-6-phosphate dehydrogenase and pyruvate kinase. Thus, pretilachlor, which is otherwise known to kill weeds by interfering with cell division, affected the growth of the cyanobacteria by interacting with PS-II.
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Brenes-Guillén L, Fuentes-Schweizer P, García-Piñeres A, Uribe-Lorío L. Tolerance and sorption of Bromacil and Paraquat by thermophilic cyanobacteria Leptolyngbya 7M from Costa Rican thermal springs. JOURNAL OF CONTAMINANT HYDROLOGY 2019; 226:103539. [PMID: 31408829 DOI: 10.1016/j.jconhyd.2019.103539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/18/2019] [Accepted: 08/01/2019] [Indexed: 06/10/2023]
Abstract
We studied the adsorption ability and tolerance of the thermophilic filamentous cyanobacteria Letolyngbya 7M towards Paraquat and Bromacil. Adsorption isotherms at pH = 7.0 showed an adsorption capacity of 24.4 mg/g and 66.8 mg/g, respectively, and a good fit to the Langmuir model (R2 = 0.97 and 0.99, respectively). To evaluate the effect of both herbicides on photosynthetic pigments and viability of cyanobacteria, cell autoflorescence and esterase activity was determined using flow cytometry. Autofluorescence was less sensitive to changes in cell viability, as it was only slightly reduced at high Paraquat and Bromacil concentrations. Herbicide effect on esterase activity is dose-dependent. Bromacil did not cause a significant effect on either chlorophyll a content or cell viability. This study demonstrates the potential of Leptolyngbya 7M to remove Paraquat and Bromacil herbicides from aqueous solution under laboratory conditions.
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Affiliation(s)
- Laura Brenes-Guillén
- Centro de Investigación en Biología Celular y Molecular, Universidad de Costa Rica, Costa Rica.
| | - Paola Fuentes-Schweizer
- Centro de Investigación en Electroquímica y Energía Química, Universidad de Costa Rica, Costa Rica; Escuela de Química, Universidad de Costa Rica, Costa Rica
| | - Alfonso García-Piñeres
- Centro de Investigación en Biología Celular y Molecular, Universidad de Costa Rica, Costa Rica; Escuela de Química, Universidad de Costa Rica, Costa Rica
| | - Lorena Uribe-Lorío
- Centro de Investigación en Biología Celular y Molecular, Universidad de Costa Rica, Costa Rica
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10
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Binding of ferredoxin NADP + oxidoreductase (FNR) to plant photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:689-698. [PMID: 31336103 DOI: 10.1016/j.bbabio.2019.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/11/2019] [Accepted: 07/18/2019] [Indexed: 12/17/2022]
Abstract
The binding of FNR to PSI has been postulated long ago, however, a clear evidence is still missing. In this work, using isothermal titration calorimetry (ITC), we found that FNR binds to photosystem I with its light harvesting complex I (PSI-LHCI) from C. reinhardtii with a 1:1 stoichiometry, a Kd of ~0.8 μM and ∆H of -20.7 kcal/mol. Titrations at different temperatures were used to determine the heat capacity change, ∆CP, of the binding, through which the size of the interface area between the proteins was assessed as ~3000 Å2. In a different set of ITC experiments, introduction of various sucrose concentrations was used to estimate that ~95 water molecules are released to the solvent. These observations support the notion of a binding site shared by few of the photosystem I - light harvesting complex I (PSI-LHCI) subunits in addition to PsaE. Based on these results, a hypothetical model was built for the binding site of FNR at PSI, using known crystallographic structures of: cyanobacterial PSI in complex with ferredoxin (Fd), plant PSI-LHCI and Fd:FNR complex from cyanobacteria. FNR binding site location is proposed to be at the foot of the stromal ridge and above the inner LHCI belt. It is expected to form contacts with PsaE, PsaB, PsaF and at least one of the LHCI. In addition, a ~4.5-fold increased affinity between FNR and PSI-LHCI under crowded 1 M sucrose environment led us to conclude that in C. reinhardtii FNR also functions as a subunit of PSI-LHCI.
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11
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Influence of Chemically Disrupted Photosynthesis on Cyanobacterial Thylakoid Dynamics in Synechocystis sp. PCC 6803. Sci Rep 2019; 9:5711. [PMID: 30952892 PMCID: PMC6450941 DOI: 10.1038/s41598-019-42024-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 03/18/2019] [Indexed: 12/22/2022] Open
Abstract
The photosynthetic machinery of the cyanobacterium Synechocystis sp. PCC 6803 resides in flattened membrane sheets called thylakoids, situated in the peripheral part of the cellular cytoplasm. Under photosynthetic conditions these thylakoid membranes undergo various dynamical processes that could be coupled to their energetic functions. Using Neutron Spin Echo Spectroscopy (NSE), we have investigated the undulation dynamics of Synechocystis sp. PCC 6803 thylakoids under normal photosynthetic conditions and under chemical treatment with DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea), an herbicide that disrupts photosynthetic electron transfer. Our measurements show that DCMU treatment has a similar effect as dark conditions, with differences in the undulation modes of the untreated cells compared to the chemically inhibited cells. We found that the disrupted membranes are 1.5-fold more rigid than the native membranes during the dark cycle, while in light they relax approximately 1.7-fold faster than native and they are 1.87-fold more flexible. The strength of the herbicide disruption effect is characterized further by the damping frequency of the relaxation mode and the decay rate of the local shape fluctuations. In the dark, local thicknesses and shape fluctuations relax twice as fast in native membranes, at 17% smaller mode amplitude, while in light the decay rate of local fluctuations is 1.2-fold faster in inhibited membranes than in native membranes, at 56% higher amplitude. The disrupted electron transfer chain and the decreased proton motive force within the lumenal space partially explain the variations observed in the mechanical properties of the Synechocystis membranes, and further support the hypothesis that the photosynthetic process is tied to thylakoid rigidity in this type of cyanobacterial cell.
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12
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Yao M, Liu Y, Fei L, Zhou Y, Wang F, Chen J. Self-Adaptable Quinone-Quinol Exchange Mechanism of Photosystem II. J Phys Chem B 2018; 122:10478-10489. [PMID: 30380868 DOI: 10.1021/acs.jpcb.8b09641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The step of plastoquinone (PQ) reduction to plastoquinol (PQH2) can regulate the photoreaction rate of photosystem II (PSII). To experimentally unravel the PQ-PQH2 exchange mechanism of PSII, we investigate the reaction kinetics of plant PSII membranes and the subunits-trimmed PSII core complexes with various PQ analogues and directly probe the reductions of PQ and other quinones by 257 nm resonance Raman scattering. Two phases of quinone concentration effect on the reaction rate originate from the quinone-quinol exchange mechanism. The results indicate that high concentrations of quinone, more than one movable quinone molecule per PSII reaction center, could trigger quinone-quinol exchange adapting to the unidirectional route: quinones enter through channel I and/or III, and quinols leave through channel II. A weak quinone binding site near QB probably plays a crucial role in pushing quinone-quinol exchange forward in the unidirectional route. Our work provides experimental proofs demonstrating a self-adaptable quinone-quinol exchange mechanism of PSII.
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Affiliation(s)
- Mingdong Yao
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics , Chinese Academy of Sciences , Dalian 116023 , China.,Key Laboratory of Systems Bioengineering (Ministry of Education) , Tianjin University , Tianjin 300072 , China
| | - Ying Liu
- Institute of Materials , China Academy of Engineering Physics , Mianyang 621907 , China
| | - Liping Fei
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics , Chinese Academy of Sciences , Dalian 116023 , China
| | - Ye Zhou
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics , Chinese Academy of Sciences , Dalian 116023 , China
| | - Fangjun Wang
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics , Chinese Academy of Sciences , Dalian 116023 , China
| | - Jun Chen
- Science and Technology on Surface Physics and Chemistry Laboratory , Jiangyou 621908 , China.,State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics , Chinese Academy of Sciences , Dalian 116023 , China
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13
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Marco P, Kozuleva M, Eilenberg H, Mazor Y, Gimeson P, Kanygin A, Redding K, Weiner I, Yacoby I. Binding of ferredoxin to algal photosystem I involves a single binding site and is composed of two thermodynamically distinct events. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:234-243. [DOI: 10.1016/j.bbabio.2018.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 01/07/2018] [Accepted: 01/08/2018] [Indexed: 10/18/2022]
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14
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Shahzad B, Tanveer M, Che Z, Rehman A, Cheema SA, Sharma A, Song H, Rehman SU, Zhaorong D. Role of 24-epibrassinolide (EBL) in mediating heavy metal and pesticide induced oxidative stress in plants: A review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 147:935-944. [PMID: 29029379 DOI: 10.1016/j.ecoenv.2017.09.066] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/20/2017] [Accepted: 09/26/2017] [Indexed: 05/18/2023]
Abstract
Industrialization and urbanization have posed serious threats to the environment. Excessive release of heavy metals from industrial effluents and overuse of pesticides in modern agriculture are limiting crop production by polluting environment and deteriorating food quality. Sustaining food quality under heavy metals and pesticide stress is crucial to meet the increasing demands for food. 24-Epibrassinolide (EBL), a ubiquitously occurring plant growth hormone shows great potential to alleviate heavy metals and pesticide stress in plants. This review sums up the potential role of EBL in ameliorating heavy metals and pesticide toxicity in plants extensively. EBL application increases plant's overall growth, biomass accumulation and photosynthetic efficiency by the modulation of numerous biochemical and physiological processes under heavy metals and pesticide stress. In addition, EBL scavenges reactive oxygen species (ROS) by triggering the production of antioxidant enzymes such as SOD, CAT, POX etc. EBL also induces the production of proline and soluble proteins that helps in maintaining osmotic potential and osmo-protection under both heavy metals and pesticide stress. At the end, future needs of research about the application of 24-epibrassinolide have also been discussed.
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Affiliation(s)
- Babar Shahzad
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia.
| | - Mohsin Tanveer
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
| | - Zhao Che
- School of Agronomy, Anhui Agricultural University, Hefei 230036, China
| | - Abdul Rehman
- Department of Agronomy, University of Agriculture Faisalabad, Pakistan
| | | | - Anket Sharma
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar 143005, Punjab, India
| | - He Song
- School of Agronomy, Anhui Agricultural University, Hefei 230036, China
| | - Shams Ur Rehman
- National Maize Key Laboratory, Department of Crop Biotechnology, School of Life Sciences, Hefei 230036, China
| | - Dong Zhaorong
- School of Agronomy, Anhui Agricultural University, Hefei 230036, China
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15
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Yotsova EK, Stefanov MA, Dobrikova AG, Apostolova EL. Different sensitivities of photosystem II in green algae and cyanobacteria to phenylurea and phenol-type herbicides: effect on electron donor side. ACTA ACUST UNITED AC 2017; 72:315-324. [PMID: 28258977 DOI: 10.1515/znc-2016-0089] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 02/05/2017] [Indexed: 11/15/2022]
Abstract
Abstract
The effects of short-term treatment with phenylurea (DCMU, isoproturon) and phenol-type (ioxynil) herbicides on the green alga Chlorella kessleri and the cyanobacterium Synechocystis salina with different organizations of photosystem II (PSII) were investigated using pulse amplitude modulated (PAM) chlorophyll fluorescence and photosynthetic oxygen evolution measured by polarographic oxygen electrodes (Clark-type and Joliot-type). The photosynthetic oxygen evolution showed stronger inhibition than the PSII photochemistry. The effects of the studied herbicides on both algal and cyanobacterial cells decreased in the following order: DCMU>isoproturon>ioxynil. Furthermore, we observed that the number of blocked PSII centers increased significantly after DCMU treatment (204–250 times) and slightly after ioxynil treatment (19–35 times) in comparison with the control cells. This study suggests that the herbicides affect not only the acceptor side but also the donor side of PSII by modifications of the Mn cluster of the oxygen-evolving complex. We propose that one of the reasons for the different PSII inhibitions caused by herbicides is their influence, in different extents, on the kinetic parameters of the oxygen-evolving reactions (the initial S0−S1 state distribution, the number of blocked centers SB, the turnover time of Si states, misses and double hits). The relationship between the herbicide-induced inhibition and the changes in the kinetic parameters is discussed.
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Affiliation(s)
- Ekaterina K Yotsova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, Sofia 1113, Bulgaria
| | - Martin A Stefanov
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, Sofia 1113, Bulgaria
| | - Anelia G Dobrikova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, Sofia 1113, Bulgaria
| | - Emilia L Apostolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria, Tel: +359-2979-2621, Fax: +359-2971-2493
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16
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Yoneda Y, Katayama T, Nagasawa Y, Miyasaka H, Umena Y. Dynamics of Excitation Energy Transfer Between the Subunits of Photosystem II Dimer. J Am Chem Soc 2016; 138:11599-605. [DOI: 10.1021/jacs.6b04316] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yusuke Yoneda
- Graduate
School of Engineering Science, Osaka University, Toyonaka, Osaka560-8531, Japan
| | - Tetsuro Katayama
- Graduate
School of Engineering Science, Osaka University, Toyonaka, Osaka560-8531, Japan
| | - Yutaka Nagasawa
- Graduate
School of Engineering Science, Osaka University, Toyonaka, Osaka560-8531, Japan
- College
of Life Science, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
- PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Hiroshi Miyasaka
- Graduate
School of Engineering Science, Osaka University, Toyonaka, Osaka560-8531, Japan
| | - Yasufumi Umena
- Research
Institute for Interdisciplinary Science, Okayama University, Kita-ku, Okayama 700-8530, Japan
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17
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Brinkert K, Le Formal F, Li X, Durrant J, Rutherford AW, Fantuzzi A. Photocurrents from photosystem II in a metal oxide hybrid system: Electron transfer pathways. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1857:1497-1505. [PMID: 26946088 PMCID: PMC4990130 DOI: 10.1016/j.bbabio.2016.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 02/19/2016] [Accepted: 03/01/2016] [Indexed: 12/21/2022]
Abstract
We have investigated the nature of the photocurrent generated by Photosystem II (PSII), the water oxidizing enzyme, isolated from Thermosynechococcus elongatus, when immobilized on nanostructured titanium dioxide on an indium tin oxide electrode (TiO2/ITO). We investigated the properties of the photocurrent from PSII when immobilized as a monolayer versus multilayers, in the presence and absence of an inhibitor that binds to the site of the exchangeable quinone (QB) and in the presence and absence of exogenous mobile electron carriers (mediators). The findings indicate that electron transfer occurs from the first quinone (QA) directly to the electrode surface but that the electron transfer through the nanostructured metal oxide is the rate-limiting step. Redox mediators enhance the photocurrent by taking electrons from the nanostructured semiconductor surface to the ITO electrode surface not from PSII. This is demonstrated by photocurrent enhancement using a mediator incapable of accepting electrons from PSII. This model for electron transfer also explains anomalies reported in the literature using similar and related systems. The slow rate of the electron transfer step in the TiO2 is due to the energy level of electron injection into the semiconducting material being below the conduction band. This limits the usefulness of the present hybrid electrode. Strategies to overcome this kinetic limitation are discussed.
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Affiliation(s)
- Katharina Brinkert
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Florian Le Formal
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - Xiaoe Li
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - James Durrant
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | | | - Andrea Fantuzzi
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
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18
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Noji T, Kawakami K, Shen JR, Dewa T, Nango M, Kamiya N, Itoh S, Jin T. Oxygen-Evolving Porous Glass Plates Containing the Photosynthetic Photosystem II Pigment-Protein Complex. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:7796-7805. [PMID: 27400072 DOI: 10.1021/acs.langmuir.6b02106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The development of artificial photosynthesis has focused on the efficient coupling of reaction at photoanode and cathode, wherein the production of hydrogen (or energy carriers) is coupled to the electrons derived from water-splitting reactions. The natural photosystem II (PSII) complex splits water efficiently using light energy. The PSII complex is a large pigment-protein complex (20 nm in diameter) containing a manganese cluster. A new photoanodic device was constructed incorporating stable PSII purified from a cyanobacterium Thermosynechococcus vulcanus through immobilization within 20 or 50 nm nanopores contained in porous glass plates (PGPs). PSII in the nanopores retained its native structure and high photoinduced water splitting activity. The photocatalytic rate (turnover frequency) of PSII in PGP was enhanced 11-fold compared to that in solution, yielding a rate of 50-300 mol e(-)/(mol PSII·s) with 2,6-dichloroindophenol (DCIP) as an electron acceptor. The PGP system realized high local concentrations of PSII and DCIP to enhance the collisional reactions in nanotubes with low disturbance of light penetration. The system allows direct visualization/determination of the reaction inside the nanotubes, which contributes to optimize the local reaction condition. The PSII/PGP device will substantively contribute to the construction of artificial photosynthesis using water as the ultimate electron source.
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Affiliation(s)
- Tomoyasu Noji
- The OCU Advanced Research Institute for Natural Science & Technology (OCARINA), Osaka City University , 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Keisuke Kawakami
- The OCU Advanced Research Institute for Natural Science & Technology (OCARINA), Osaka City University , 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Jian-Ren Shen
- Photosynthesis Research Center, Graduate School of Natural Science and Technology/Faculty of Science, Okayama University , Okayama 700-8530, Japan
| | - Takehisa Dewa
- Department of Life Science and Applied Chemistry, Graduate School of Engineering, Nagoya Institute of Technology , Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
| | - Mamoru Nango
- The OCU Advanced Research Institute for Natural Science & Technology (OCARINA), Osaka City University , 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Nobuo Kamiya
- The OCU Advanced Research Institute for Natural Science & Technology (OCARINA), Osaka City University , 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Shigeru Itoh
- Graduate School of Science, Nagoya University , Furo-cho, Chikusa-ku Nagoya, Aichi 464-8602, Japan
| | - Tetsuro Jin
- Inorganic Functional Materials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , 1-8-31, Midorigaoka, Ikeda, Osaka 563-8577, Japan
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19
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Sauter NK, Echols N, Adams PD, Zwart PH, Kern J, Brewster AS, Koroidov S, Alonso-Mori R, Zouni A, Messinger J, Bergmann U, Yano J, Yachandra VK. No observable conformational changes in PSII. Nature 2016; 533:E1-2. [PMID: 27193689 DOI: 10.1038/nature17983] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/21/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Nicholas K Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Nathaniel Echols
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Paul D Adams
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Petrus H Zwart
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Aaron S Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Sergey Koroidov
- Institutionen för Kemi, Kemiskt Biologiskt Centrum, Umeå Universitet, 90187 Umeå, Sweden
| | - Roberto Alonso-Mori
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Athina Zouni
- Institut für Biologie, Humboldt-Universität zu Berlin, D-10099 Berlin, Germany
| | - Johannes Messinger
- Institutionen för Kemi, Kemiskt Biologiskt Centrum, Umeå Universitet, 90187 Umeå, Sweden
| | - Uwe Bergmann
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Vittal K Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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20
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Khan S, Sun JS, Brudvig GW. Cation Effects on the Electron-Acceptor Side of Photosystem II. J Phys Chem B 2015; 119:7722-8. [DOI: 10.1021/jp513035u] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Sahr Khan
- Department
of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Jennifer S. Sun
- Department
of Molecular, Cellular, and Developmental Biology, Yale University, 219
Prospect Street, New Haven, Connecticut 06520-8114, United States
| | - Gary W. Brudvig
- Department
of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
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21
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Deng C, Shao H, Pan X, Wang S, Zhang D. Herbicidal effects of harmaline from Peganum harmala on photosynthesis of Chlorella pyrenoidosa: probed by chlorophyll fluorescence and thermoluminescence. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2014; 115:23-31. [PMID: 25307462 DOI: 10.1016/j.pestbp.2014.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 07/25/2014] [Accepted: 08/12/2014] [Indexed: 05/26/2023]
Abstract
The herbicidal effects of harmaline extracted from Peganum harmala seed on cell growth and photosynthesis of green algae Chlorella pyrenoidosa were investigated using chlorophyll a fluorescence and thermoluminescence techniques. Exposure to harmaline inhibited cell growth, pigments contents and oxygen evolution of C. pyrenoidosa. Oxygen evolution was more sensitive to harmaline toxicity than cell growth or the whole photosystem II (PSII) activity, maybe it was the first target site of harmaline. The JIP-test parameters showed that harmaline inhibited the donor side of PSII. Harmaline decreased photochemical efficiency and electron transport flow of PSII but increased the energy dissipation. The charge recombination was also affected by harmaline. Amplitude of the fast phase decreased and the slow phase increased at the highest level of harmaline. Electron transfer from QA(-) to QB was inhibited and backward electron transport flow from QA(-) to oxygen evolution complex was enhanced at 10 μg mL(-1) harmaline. Exposure to 10 μg mL(-1) harmaline caused appearance of C band in thermoluminescence. Exposure to 5 μg mL(-1) harmaline inhibited the formation of proton gradient. The highest concentration of harmaline treatment inhibited S3QB(-) charge recombination but promoted formation of QA(-)YD(+) charge pairs. P. harmala harmaline may be a promising herbicide because of its inhibition of cell growth, pigments synthesis, oxygen evolution and PSII activities.
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Affiliation(s)
- Chunnuan Deng
- Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; College of Tourism and Geography, Yunnan Normal University, Kunming 650500, China
| | - Hua Shao
- Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
| | - Xiangliang Pan
- Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
| | - Shuzhi Wang
- Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Daoyong Zhang
- Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
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22
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Singh DP, Khattar JIS, Gupta M, Kaur G. Evaluation of toxicological impact of cartap hydrochloride on some physiological activities of a non-heterocystous cyanobacterium Leptolyngbya foveolarum. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2014; 110:63-70. [PMID: 24759053 DOI: 10.1016/j.pestbp.2014.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 02/08/2014] [Accepted: 03/05/2014] [Indexed: 06/03/2023]
Abstract
The present study was aimed to the evaluation of toxicological impact of insecticide cartap hydrochloride on photosynthesis and nitrogen assimilation of a non-heterocystous cyanoprokaryote Leptolyngbya foveolarum isolated from paddy fields of Punjab, India. The microorganism tolerated commercial grade insecticide up to 80 ppm. Lower concentration (20 ppm) of cartap supported good growth with high dry weight of biomass, total protein content, photosynthetic pigments, photosynthesis and respiration compared to untreated control cultures while higher concentrations (40 and 60 ppm) inhibited these parameters in a dose dependent manner. Treatment of the microorganism with 60 ppm cartap lowered the content of photosynthetic pigments with maximum inhibitory effect on phycoerythrin (70% decrease) followed by allophycocyanin (66% decrease). Rates of photosynthesis and respiration were inhibited by 63% and 45%, respectively, while PS-I, II and whole chain activity were decreased by 45%, 67% and 40% respectively, compared to untreated control cultures. Cartap at 60 ppm decreased nitrate and nitrite uptake by 31% and 61%, respectively, whereas uptake of ammonium was slightly increased (18%) in cartap (60 ppm) treated cells. Nitrate and nitrite reductase, and glutamine synthetase activities of the microorganism decreased by 36-50% in 60 ppm cartap. The low levels of growth, photosynthetic pigments and activities of nitrogen assimilating enzymes in cells grown in nitrogen depleted medium supplement with insecticide indicated that insecticide may be used by the organism as a nitrogen source.
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Affiliation(s)
- D P Singh
- Department of Botany, Punjabi University, Patiala 147002, India.
| | - J I S Khattar
- Department of Botany, Punjabi University, Patiala 147002, India
| | - Meenu Gupta
- Department of Botany, Punjabi University, Patiala 147002, India
| | - Gurdeep Kaur
- Department of Botany, Punjabi University, Patiala 147002, India
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23
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Müh F, Zouni A. The nonheme iron in photosystem II. PHOTOSYNTHESIS RESEARCH 2013; 116:295-314. [PMID: 24077892 DOI: 10.1007/s11120-013-9926-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 09/17/2013] [Indexed: 06/02/2023]
Abstract
Photosystem II (PSII), the light-driven water:plastoquinone (PQ) oxidoreductase of oxygenic photosynthesis, contains a nonheme iron (NHI) at its electron acceptor side. The NHI is situated between the two PQs QA and QB that serve as one-electron transmitter and substrate of the reductase part of PSII, respectively. Among the ligands of the NHI is a (bi)carbonate originating from CO2, the substrate of the dark reactions of oxygenic photosynthesis. Based on recent advances in the crystallography of PSII, we review the structure of the NHI in PSII and discuss ideas concerning its function and the role of bicarbonate along with a comparison to the reaction center of purple bacteria and other enzymes containing a mononuclear NHI site.
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Rajarathnam K, Rösgen J. Isothermal titration calorimetry of membrane proteins - progress and challenges. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:69-77. [PMID: 23747362 DOI: 10.1016/j.bbamem.2013.05.023] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 05/16/2013] [Accepted: 05/20/2013] [Indexed: 11/20/2022]
Abstract
Integral membrane proteins, including G protein-coupled receptors (GPCR) and ion channels, mediate diverse biological functions that are crucial to all aspects of life. The knowledge of the molecular mechanisms, and in particular, the thermodynamic basis of the binding interactions of the extracellular ligands and intracellular effector proteins is essential to understand the workings of these remarkable nanomachines. In this review, we describe how isothermal titration calorimetry (ITC) can be effectively used to gain valuable insights into the thermodynamic signatures (enthalpy, entropy, affinity, and stoichiometry), which would be most useful for drug discovery studies, considering that more than 30% of the current drugs target membrane proteins. This article is part of a Special Issue entitled: Structural and biophysical characterisation of membrane protein-ligand binding.
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Affiliation(s)
- Krishna Rajarathnam
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX 77555, USA.
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Singh DP, Khattar JIS, Kaur M, Kaur G, Gupta M, Singh Y. Anilofos tolerance and its mineralization by the cyanobacterium Synechocystis sp. strain PUPCCC 64. PLoS One 2013; 8:e53445. [PMID: 23382844 PMCID: PMC3561370 DOI: 10.1371/journal.pone.0053445] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 11/28/2012] [Indexed: 11/19/2022] Open
Abstract
This study deals with anilofos tolerance and its mineralization by the common rice field cyanobacterium Synechocystis sp. strain PUPCCC 64. The organism tolerated anilofos up to 25 mg L−1. The herbicide caused inhibitory effects on photosynthetic pigments of the test organism in a dose-dependent manner. The organism exhibited 60, 89, 96, 85 and 79% decrease in chlorophyll a, carotenoids, phycocyanin, allophycocyanin and phycoerythrin, respectively, in 20 mg L−1 anilofos on day six. Activities of superoxide dismutase, catalase and peroxidase increased by 1.04 to 1.80 times over control cultures in presence of 20 mg L−1 anilofos. Glutathione content decreased by 26% while proline content was unaffected by 20 mg L−1 anilofos. The test organism showed intracellular uptake and metabolized the herbicide. Uptake of herbicide by test organism was fast during initial six hours followed by slow uptake until 120 hours. The organism exhibited maximum anilofos removal at 100 mg protein L−1, pH 8.0 and 30°C. Its growth in phosphate deficient basal medium in the presence of anilofos (2.5 mg L−1) indicated that herbicide was used by the strain PUPCCC 64 as a source of phosphate.
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Affiliation(s)
- D P Singh
- Department of Botany, Punjabi University, Patiala, Punjab, India.
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Wöhri AB, Hillertz P, Eriksson PO, Meuller J, Dekker N, Snijder A. Thermodynamic studies of ligand binding to the human homopentameric glycine receptor using isothermal titration calorimetry. Mol Membr Biol 2012; 30:169-83. [DOI: 10.3109/09687688.2012.696733] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Broser M, Glöckner C, Gabdulkhakov A, Guskov A, Buchta J, Kern J, Müh F, Dau H, Saenger W, Zouni A. Structural basis of cyanobacterial photosystem II Inhibition by the herbicide terbutryn. J Biol Chem 2011; 286:15964-72. [PMID: 21367867 DOI: 10.1074/jbc.m110.215970] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Herbicides that target photosystem II (PSII) compete with the native electron acceptor plastoquinone for binding at the Q(B) site in the D1 subunit and thus block the electron transfer from Q(A) to Q(B). Here, we present the first crystal structure of PSII with a bound herbicide at a resolution of 3.2 Å. The crystallized PSII core complexes were isolated from the thermophilic cyanobacterium Thermosynechococcus elongatus. The used herbicide terbutryn is found to bind via at least two hydrogen bonds to the Q(B) site similar to photosynthetic reaction centers in anoxygenic purple bacteria. Herbicide binding to PSII is also discussed regarding the influence on the redox potential of Q(A), which is known to affect photoinhibition. We further identified a second and novel chloride position close to the water-oxidizing complex and in the vicinity of the chloride ion reported earlier (Guskov, A., Kern, J., Gabdulkhakov, A., Broser, M., Zouni, A., and Saenger, W. (2009) Nat. Struct. Mol. Biol. 16, 334-342). This discovery is discussed in the context of proton transfer to the lumen.
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Affiliation(s)
- Matthias Broser
- Institut für Chemie/Max-Volmer-Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, Berlin, Germany
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Guskov A, Gabdulkhakov A, Broser M, Glöckner C, Hellmich J, Kern J, Frank J, Müh F, Saenger W, Zouni A. Recent Progress in the Crystallographic Studies of Photosystem II. Chemphyschem 2010; 11:1160-71. [DOI: 10.1002/cphc.200900901] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Takano A, Takahashi R, Suzuki H, Noguchi T. Herbicide effect on the hydrogen-bonding interaction of the primary quinone electron acceptor QA in photosystem II as studied by Fourier transform infrared spectroscopy. PHOTOSYNTHESIS RESEARCH 2008; 98:159-167. [PMID: 18425599 DOI: 10.1007/s11120-008-9302-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2007] [Accepted: 03/31/2008] [Indexed: 05/26/2023]
Abstract
The redox potential of Q(A) in photosystem II (PSII) is known to be lower by approximately 100 mV in the presence of phenolic herbicides compared with the presence of DCMU-type herbicides. In this study, the structural basis underlying the herbicide effects on the Q(A) redox potential was studied using Fourier transform infrared (FTIR) spectroscopy. Light-induced Q(A)(-)/Q(A) FTIR difference spectra of Mn-depleted PSII membranes in the presence of DCMU, atrazine, terbutryn, and bromacil showed a strong CO stretching peak of Q(A)(-) at 1,479 cm(-1), while binding of phenolic herbicides, bromoxynil and ioxynil, induced a small but clear downshift by approximately 1 cm(-1). The CO peak positions and the small frequency difference were reproduced in the S(2)Q(A)(-)/S(1)Q(A) spectra of oxygen-evolving PSII membranes with DCMU and bromoxynil. The relationship of the CO frequency with herbicide species correlated well with that of the peak temperatures of thermoluminescence due to S(2)Q(A)(-) recombination. Density functional theory calculations of model hydrogen-bonded complexes of plastoquinone radical anion showed that the small shift of the CO frequency is consistent with a change in the hydrogen-bond structure most likely as a change in its strength. The Q(A)(-)/Q(A) spectra in the presence of bromoxynil, and ioxynil, which bear a nitrile group in the phenolic ring, also showed CN stretching bands around 2,210 cm(-1). Comparison with the CN frequencies of bromoxynil in solutions suggested that the phenolic herbicides take a phenotate anion form in the Q(B) pocket. It was proposed that interaction of the phenolic C-O(-) with D1-His215 changes the strength of the hydrogen bond between the CO of Q(A) with D2-His214 via the iron-histidine bridge, causing the decrease in the Q(A) redox potential.
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Affiliation(s)
- Akira Takano
- Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
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Okhrimenko O, Jelesarov I. A survey of the year 2006 literature on applications of isothermal titration calorimetry. J Mol Recognit 2008; 21:1-19. [DOI: 10.1002/jmr.859] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Suhai T, Dencher NA, Poetsch A, Seelert H. Remarkable stability of the proton translocating F1FO-ATP synthase from the thermophilic cyanobacterium Thermosynechococcus elongatus BP-1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1778:1131-40. [PMID: 18206981 DOI: 10.1016/j.bbamem.2007.12.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Revised: 11/28/2007] [Accepted: 12/13/2007] [Indexed: 10/22/2022]
Abstract
For functional characterization, we isolated the F1FO-ATP synthase of the thermophilic cyanobacterium Thermosynechococcus elongatus. Because of the high content of phycobilisomes, a combination of dye-ligand chromatography and anion exchange chromatography was necessary to yield highly pure ATP synthase. All nine single F1FO subunits were identified by mass spectrometry. Western blotting revealed the SDS stable oligomer of subunits c in T. elongatus. In contrast to the mass archived in the database (10,141 Da), MALDI-TOF-MS revealed a mass of the subunit c monomer of only 8238 Da. A notable feature of the ATP synthase was its ability to synthesize ATP in a wide temperature range and its stability against chaotropic reagents. After reconstitution of F1FO into liposomes, ATP synthesis energized by an applied electrochemical proton gradient demonstrated functional integrity. The highest ATP synthesis rate was determined at the natural growth temperature of 55 degrees C, but even at 95 degrees C ATP production occurred. In contrast to other prokaryotic and eukaryotic ATP synthases which can be disassembled with Coomassie dye into the membrane integral and the hydrophilic part, the F1FO-ATP synthase possessed a particular stability. Also with the chaotropic reagents sodium bromide and guanidine thiocyanate, significantly harsher conditions were required for disassembly of the thermophilic ATP synthase.
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Affiliation(s)
- Tina Suhai
- Physical Biochemistry, Department of Chemistry, Darmstadt University of Technology, Petersenstrasse 22, D-64287 Darmstadt, Germany
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Kern J, Renger G. Photosystem II: structure and mechanism of the water:plastoquinone oxidoreductase. PHOTOSYNTHESIS RESEARCH 2007; 94:183-202. [PMID: 17634752 DOI: 10.1007/s11120-007-9201-1] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 05/16/2007] [Indexed: 05/07/2023]
Abstract
This mini-review briefly summarizes our current knowledge on the reaction pattern of light-driven water splitting and the structure of Photosystem II that acts as a water:plastoquinone oxidoreductase. The overall process comprises three types of reaction sequences: (a) light-induced charge separation leading to formation of the radical ion pair P680+*QA(-*) ; (b) reduction of plastoquinone to plastoquinol at the QB site via a two-step reaction sequence with QA(-*) as reductant and (c) oxidative water splitting into O2 and four protons at a manganese-containing catalytic site via a four-step sequence driven by P680+* as oxidant and a redox active tyrosine YZ acting as mediator. Based on recent progress in X-ray diffraction crystallographic structure analysis the array of the cofactors within the protein matrix is discussed in relation to the functional pattern. Special emphasis is paid on the structure of the catalytic sites of PQH2 formation (QB-site) and oxidative water splitting (Mn4OxCa cluster). The energetics and kinetics of the reactions taking place at these sites are presented only in a very concise manner with reference to recent up-to-date reviews. It is illustrated that several questions on the mechanism of oxidative water splitting and the structure of the catalytic sites are far from being satisfactorily answered.
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Affiliation(s)
- Jan Kern
- Institut für Chemie, Max-Volmer-Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, 10623, Berlin, Germany.
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Kern J, Biesiadka J, Loll B, Saenger W, Zouni A. Structure of the Mn4-Ca cluster as derived from X-ray diffraction. PHOTOSYNTHESIS RESEARCH 2007; 92:389-405. [PMID: 17492491 DOI: 10.1007/s11120-007-9173-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Accepted: 04/10/2007] [Indexed: 05/15/2023]
Abstract
The catalytic centre for light-induced water oxidation in photosystem II (PSII) is a multinuclear metal cluster containing four manganese and one calcium cations. Knowing the structure of this biological catalyst is of utmost importance for unravelling the mechanism of water oxidation in photosynthesis. In this review we describe the current state of the X-ray structure determination at 3.0 A resolution of the water oxidation complex (WOC) of PSII. The arrangement of metal cations in the cluster, their coordination and protein surroundings are discussed with regard to spectroscopic and mutagenesis studies. Limitations of the presently available structural data are pointed out and possible perspectives for the future are outlined, including the combination of X-ray diffraction and X-ray spectroscopy on single crystals.
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Affiliation(s)
- Jan Kern
- Institut für Chemie, Max Volmer Laboratorium für Biophysikalische Chemie, Sekr. PC 14, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
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Krivanek R, Kern J, Zouni A, Dau H, Haumann M. Spare quinones in the QB cavity of crystallized photosystem II from Thermosynechococcus elongatus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:520-7. [PMID: 17397795 DOI: 10.1016/j.bbabio.2007.02.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 02/13/2007] [Accepted: 02/19/2007] [Indexed: 11/25/2022]
Abstract
The recent crystallographic structure at 3.0 A resolution of PSII from Thermosynechococcus elongatus has revealed a cavity in the protein which connects the membrane phase to the binding pocket of the secondary plastoquinone Q(B). The cavity may serve as a quinone diffusion pathway. By fluorescence methods, electron transfer at the donor and acceptor sides was investigated in the same membrane-free PSII core particle preparation from T. elongatus prior to and after crystallization; PSII membrane fragments from spinach were studied as a reference. The data suggest selective enrichment of those PSII centers in the crystal that are intact with respect to O(2) evolution at the manganese-calcium complex of water oxidation and with respect to the integrity of the quinone binding site. One and more functional quinone molecules (per PSII monomer) besides of Q(A) and Q(B) were found in the crystallized PSII. We propose that the extra quinones are located in the Q(B) cavity and serve as a PSII intrinsic pool of electron acceptors.
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Affiliation(s)
- Roland Krivanek
- Freie Universität Berlin, FB Physik, Arnimallee 14, D-14195 Berlin, Germany
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Kargul J, Maghlaoui K, Murray JW, Deak Z, Boussac A, Rutherford AW, Vass I, Barber J. Purification, crystallization and X-ray diffraction analyses of the T. elongatus PSII core dimer with strontium replacing calcium in the oxygen-evolving complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:404-13. [PMID: 17321490 DOI: 10.1016/j.bbabio.2007.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2006] [Revised: 01/05/2007] [Accepted: 01/09/2007] [Indexed: 11/17/2022]
Abstract
The core complex of photosystem II (PSII) was purified from thermophilic cyanobacterium Thermosynechococcus elongatus grown in Sr(2+)-containing and Ca(2+)-free medium. Functional in vivo incorporation of Sr(2+) into the oxygen-evolving complex (OEC) was confirmed by EPR analysis of the isolated and highly purified SrPSII complex in agreement with the previous study of Boussac et al. [J. Biol. Chem. 279 (2004) 22809-22819]. Three-dimensional crystals of SrPSII complex were obtained which diffracted to 3.9 A and belonged to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions of a=133.6 A, b=236.6 A, c=307.8 A. Anomalous diffraction data collected at the Sr K-X-ray absorption edge identified a novel Sr(2+)-binding site which, within the resolution of these data (6.5 A), is consistent with the positioning of Ca(2+) in the recent crystallographic models of PSII [Ferreira et al. Science 303 (2004) 1831-1838, Loll et al. Nature 438 (2005) 1040-1044]. Fluorescence measurements on SrPSII crystals confirmed that crystallized SrPSII was active in transferring electrons from the OEC to the acceptor site of the reaction centre. However, SrPSII showed altered functional properties of its modified OEC in comparison with that of the CaPSII counterpart: slowdown of the Q(A)-to-Q(B) electron transfer and stabilized S(2)Q(A)(-) charge recombination.
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Affiliation(s)
- Joanna Kargul
- Wolfson Laboratories, Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London, UK
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Loll B, Kern J, Saenger W, Zouni A, Biesiadka J. Lipids in photosystem II: interactions with protein and cofactors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:509-19. [PMID: 17292322 DOI: 10.1016/j.bbabio.2006.12.009] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Revised: 12/14/2006] [Accepted: 12/19/2006] [Indexed: 10/23/2022]
Abstract
Photosystem II (PSII) is a homodimeric protein-cofactor complex embedded in the thylakoid membrane that catalyses light-driven charge separation accompanied by the oxidation of water during oxygenic photosynthesis. Biochemical analysis of the lipid content of PSII indicates a number of integral lipids, their composition being similar to the average lipid composition of the thylakoid membrane. The crystal structure of PSII at 3.0 A resolution allowed for the first time the assignment of 14 integral lipids within the protein scaffold, all of them being located at the interface of different protein subunits. The reaction centre subunits D1 and D2 are encircled by a belt of 11 lipids providing a flexible environment for the exchange of D1. Three lipids are located in the dimerization interface and mediate interactions between the PSII monomers. Several lipids are located close to the binding pocket of the mobile plastoquinone Q(B), forming part of a postulated diffusion pathway for plastoquinone. Furthermore two lipids were found, each ligating one antenna chlorophyll a. A detailed analysis of lipid-protein and lipid-cofactor interactions allows to derive some general principles of lipid binding pockets in PSII and to suggest possible functional properties of the various identified lipid molecules.
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Affiliation(s)
- Bernhard Loll
- Institut für Chemie und Biochemie/Kristallographie, Freie Universität Berlin, Takustrasse 6, D-14195 Berlin, Germany
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