1
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Gray C, Kailas L, Adams PG, Duffy CDP. Unravelling the fluorescence kinetics of light-harvesting proteins with simulated measurements. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149004. [PMID: 37699505 DOI: 10.1016/j.bbabio.2023.149004] [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: 02/21/2023] [Revised: 08/24/2023] [Accepted: 08/31/2023] [Indexed: 09/14/2023]
Abstract
The plant light-harvesting pigment-protein complex LHCII is the major antenna sub-unit of PSII and is generally (though not universally) accepted to play a role in photoprotective energy dissipation under high light conditions, a process known Non-Photochemical Quenching (NPQ). The underlying mechanisms of energy trapping and dissipation within LHCII are still debated. Various models have been proposed for the underlying molecular detail of NPQ, but they are often based on different interpretations of very similar transient absorption measurements of isolated complexes. Here we present a simulated measurement of the fluorescence decay kinetics of quenched LHCII aggregates to determine whether this relatively simple measurement can discriminate between different potential NPQ mechanisms. We simulate not just the underlying physics (excitation, energy migration, quenching and singlet-singlet annihilation) but also the signal detection and typical experimental data analysis. Comparing this to a selection of published fluorescence decay kinetics we find that: (1) Different proposed quenching mechanisms produce noticeably different fluorescence kinetics even at low (annihilation free) excitation density, though the degree of difference is dependent on pulse width. (2) Measured decay kinetics are consistent with most LHCII trimers becoming relatively slow excitation quenchers. A small sub-population of very fast quenchers produces kinetics which do not resemble any observed measurement. (3) It is necessary to consider at least two distinct quenching mechanisms in order to accurately reproduce experimental kinetics, supporting the idea that NPQ is not a simple binary switch.
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Affiliation(s)
- Callum Gray
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End, London E1 4NS, United Kingdom
| | - Lekshmi Kailas
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Peter G Adams
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Christopher D P Duffy
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End, London E1 4NS, United Kingdom.
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2
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Li DH, Wilson S, Mastroianni G, Ruban AV. Altered lipid acyl chain length controls energy dissipation in light-harvesting complex II proteoliposomes by hydrophobic mismatch. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2023; 246:112758. [PMID: 37531665 DOI: 10.1016/j.jphotobiol.2023.112758] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 08/04/2023]
Abstract
In plants, the major light-harvesting antenna complex (LHCII) is vital for both light harvesting and photoprotection in photosystem II. Previously, we proposed that the thylakoid membrane itself could switch LHCII into the photoprotective state, qE, via a process known as hydrophobic mismatch. The decrease in the membrane thickness that followed the formation of ΔpH was a key fact that prompted this idea. To test this, we made proteoliposomes from lipids with altered acyl chain length (ACL). Here, we show that ACL regulates the average chlorophyll fluorescence lifetime of LHCII. For liposomes made of lipids with an ACL of 18 carbons, the lifetime was ∼2 ns, like that for the thylakoid membrane. Furthermore, LHCII appears to be quenched in proteoliposomes with an ACL both shorter and longer than 18 carbons. The proteoliposomes made of short ACL lipids display structural heterogeneity revealing two quenched conformations of LHCII, each having characteristic 77 K fluorescence spectra. One conformation spectrally resembles isolated LHCII aggregates, whilst the other resembles LHCII immobilized in polyacrylamide gels. Overall, the decrease in the ACL appears to produce quenched conformations of LHCII, which renders plausible the idea that the trigger of qE is the hydrophobic mismatch.
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Affiliation(s)
- Dan-Hong Li
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
| | - Sam Wilson
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
| | - Giulia Mastroianni
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
| | - Alexander V Ruban
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
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3
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Ruan M, Li H, Zhang Y, Zhao R, Zhang J, Wang Y, Gao J, Wang Z, Wang Y, Sun D, Ding W, Weng Y. Cryo-EM structures of LHCII in photo-active and photo-protecting states reveal allosteric regulation of light harvesting and excess energy dissipation. NATURE PLANTS 2023; 9:1547-1557. [PMID: 37653340 DOI: 10.1038/s41477-023-01500-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 07/26/2023] [Indexed: 09/02/2023]
Abstract
The major light-harvesting complex of photosystem II (LHCII) has a dual regulatory function in a process called non-photochemical quenching to avoid the formation of reactive oxygen. LHCII undergoes reversible conformation transitions to switch between a light-harvesting state for excited-state energy transfer and an energy-quenching state for dissipating excess energy under full sunshine. Here we report cryo-electron microscopy structures of LHCII in membrane nanodiscs, which mimic in vivo LHCII, and in detergent solution at pH 7.8 and 5.4, respectively. We found that, under low pH conditions, the salt bridges at the lumenal side of LHCII are broken, accompanied by the formation of two local α-helices on the lumen side. The formation of α-helices in turn triggers allosterically global protein conformational change, resulting in a smaller crossing angle between transmembrane helices. The fluorescence decay rates corresponding to different conformational states follow the Dexter energy transfer mechanism with a characteristic transition distance of 5.6 Å between Lut1 and Chl612. The experimental observations are consistent with the computed electronic coupling strengths using multistate density function theory.
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Affiliation(s)
- Meixia Ruan
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hao Li
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Ying Zhang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ruoqi Zhao
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Jun Zhang
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Yingjie Wang
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Jiali Gao
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China.
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China.
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, MN, USA.
| | - Zhuan Wang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Yumei Wang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Dapeng Sun
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Wei Ding
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Yuxiang Weng
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
- Songshan Lake Materials Laboratory, Dongguan, China.
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4
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Navakoudis E, Stergiannakos T, Daskalakis V. A perspective on the major light-harvesting complex dynamics under the effect of pH, salts, and the photoprotective PsbS protein. PHOTOSYNTHESIS RESEARCH 2023; 156:163-177. [PMID: 35816266 PMCID: PMC10070230 DOI: 10.1007/s11120-022-00935-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
The photosynthetic apparatus is a highly modular assembly of large pigment-binding proteins. Complexes called antennae can capture the sunlight and direct it from the periphery of two Photosystems (I, II) to the core reaction centers, where it is converted into chemical energy. The apparatus must cope with the natural light fluctuations that can become detrimental to the viability of the photosynthetic organism. Here we present an atomic scale view of the photoprotective mechanism that is activated on this line of defense by several photosynthetic organisms to avoid overexcitation upon excess illumination. We provide a complete macroscopic to microscopic picture with specific details on the conformations of the major antenna of Photosystem II that could be associated with the switch from the light-harvesting to the photoprotective state. This is achieved by combining insight from both experiments and all-atom simulations from our group and the literature in a perspective article.
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Affiliation(s)
- Eleni Navakoudis
- Department of Chemical Engineering, Cyprus University of Technology, 95 Eirinis Street, 3603, Limassol, Cyprus
| | - Taxiarchis Stergiannakos
- Department of Chemical Engineering, Cyprus University of Technology, 95 Eirinis Street, 3603, Limassol, Cyprus
| | - Vangelis Daskalakis
- Department of Chemical Engineering, Cyprus University of Technology, 95 Eirinis Street, 3603, Limassol, Cyprus.
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5
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Bru P, Steen CJ, Park S, Amstutz CL, Sylak-Glassman EJ, Lam L, Fekete A, Mueller MJ, Longoni F, Fleming GR, Niyogi KK, Malnoë A. The major trimeric antenna complexes serve as a site for qH-energy dissipation in plants. J Biol Chem 2022; 298:102519. [PMID: 36152752 PMCID: PMC9615032 DOI: 10.1016/j.jbc.2022.102519] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 09/08/2022] [Accepted: 09/10/2022] [Indexed: 11/28/2022] Open
Abstract
Plants and algae are faced with a conundrum: harvesting sufficient light to drive their metabolic needs while dissipating light in excess to prevent photodamage, a process known as nonphotochemical quenching. A slowly relaxing form of energy dissipation, termed qH, is critical for plants’ survival under abiotic stress; however, qH location in the photosynthetic membrane is unresolved. Here, we tested whether we could isolate subcomplexes from plants in which qH was induced that would remain in an energy-dissipative state. Interestingly, we found that chlorophyll (Chl) fluorescence lifetimes were decreased by qH in isolated major trimeric antenna complexes, indicating that they serve as a site for qH-energy dissipation and providing a natively quenched complex with physiological relevance to natural conditions. Next, we monitored the changes in thylakoid pigment, protein, and lipid contents of antenna with active or inactive qH but did not detect any evident differences. Finally, we investigated whether specific subunits of the major antenna complexes were required for qH but found that qH was insensitive to trimer composition. Because we previously observed that qH can occur in the absence of specific xanthophylls, and no evident changes in pigments, proteins, or lipids were detected, we tentatively propose that the energy-dissipative state reported here may stem from Chl–Chl excitonic interaction.
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Affiliation(s)
- Pierrick Bru
- Umeå Plant Science Centre (UPSC), Department of Plant Physiology, Umeå University, 901 87 Umeå, Sweden
| | - Collin J Steen
- Department of Chemistry, University of California, Berkeley, CA 94720, USA; Molecular Biophysics and Integrated Bioimaging Division (formerly Physical Biosciences Division), Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Kavli Energy Nanoscience Institute, Berkeley, CA 94720, USA
| | - Soomin Park
- Department of Chemistry, University of California, Berkeley, CA 94720, USA; Molecular Biophysics and Integrated Bioimaging Division (formerly Physical Biosciences Division), Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Kavli Energy Nanoscience Institute, Berkeley, CA 94720, USA; School of Energy, Materials and Chemical Engineering, Korea University of Technology and Education, Cheonan, Chungnam 31253, Republic of Korea
| | - Cynthia L Amstutz
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Emily J Sylak-Glassman
- Department of Chemistry, University of California, Berkeley, CA 94720, USA; Molecular Biophysics and Integrated Bioimaging Division (formerly Physical Biosciences Division), Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Lam Lam
- Molecular Biophysics and Integrated Bioimaging Division (formerly Physical Biosciences Division), Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Kavli Energy Nanoscience Institute, Berkeley, CA 94720, USA; Graduate Group in Biophysics, University of California, Berkeley, CA 94720, USA
| | - Agnes Fekete
- Julius-von-Sachs-Institute, Biocenter, Pharmaceutical Biology, University of Wuerzburg, D-97082 Wuerzburg, Germany
| | - Martin J Mueller
- Julius-von-Sachs-Institute, Biocenter, Pharmaceutical Biology, University of Wuerzburg, D-97082 Wuerzburg, Germany
| | - Fiamma Longoni
- Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Graham R Fleming
- Department of Chemistry, University of California, Berkeley, CA 94720, USA; Molecular Biophysics and Integrated Bioimaging Division (formerly Physical Biosciences Division), Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Kavli Energy Nanoscience Institute, Berkeley, CA 94720, USA; Graduate Group in Biophysics, University of California, Berkeley, CA 94720, USA
| | - Krishna K Niyogi
- Molecular Biophysics and Integrated Bioimaging Division (formerly Physical Biosciences Division), Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Alizée Malnoë
- Umeå Plant Science Centre (UPSC), Department of Plant Physiology, Umeå University, 901 87 Umeå, Sweden.
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6
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Wilson S, Li DH, Ruban AV. The Structural and Spectral Features of Light-Harvesting Complex II Proteoliposomes Mimic Those of Native Thylakoid Membranes. J Phys Chem Lett 2022; 13:5683-5691. [PMID: 35709359 PMCID: PMC9237827 DOI: 10.1021/acs.jpclett.2c01019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
The major photosystem II light-harvesting antenna (LHCII) is the most abundant membrane protein in nature and plays an indispensable role in light harvesting and photoprotection in the plant thylakoid. Here, we show that "pseudothylakoid characteristics" can be observed in artificial LHCII membranes. In our proteoliposomal system, at high LHCII densities, the liposomes become stacked, mimicking the in vivo thylakoid grana membranes. Furthermore, an unexpected, unstructured emission peak at ∼730 nm appears, similar in appearance to photosystem I emission, but with a clear excimeric character that has never been previously reported. These states correlate with the increasing density of LHCII in the membrane and a decrease in its average fluorescence lifetime. The appearance of these low-energy states can also occur in natural plant membrane structures, which has unique consequences for the interpretation of the spectroscopic and physiological properties of the photosynthetic membrane.
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7
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Brotosudarmo THP, Wittmann B, Seki S, Fujii R, Köhler J. Wavelength-Dependent Optical Response of Single Photosynthetic Antenna Complexes from Siphonous Green Alga Codium fragile. J Phys Chem Lett 2022; 13:5226-5231. [PMID: 35670598 DOI: 10.1021/acs.jpclett.2c01160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The siphonaxanthin-siphonein-Chl-a/b-protein (SCP) complex from the siphonous green alga Codium fragile is the major light-harvesting complex (LHC) of these alga and is highly homologous to that of green plants (trimeric pigment-protein complex, LHCII). Interestingly, we find remarkable differences in the spectral response from individual SCP complexes when excited at 561 and 639 nm. While excitation in the green spectral range reproduces the common LHCII-like emission features for most of the complexes, excitation in the red spectral range yields a red-shifted emission and a significant reduction of the fluorescence decay time. We hypothesize that the difference in spectral response of SCP to light in the green and red spectral ranges can be associated with the adaption of the algae to their natural habitat under water, where sudden intensity changes are diminished, and excess light features a red-enhanced spectrum that comes at tidal timings.
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Affiliation(s)
- Tatas Hardo Panintingjati Brotosudarmo
- Spectroscopy of Soft Matter, University of Bayreuth, 95440 Bayreuth, Germany
- Department of Food Technology, Universitas Ciputra, Citraland CBD Boulevard, Surabaya 60219, Indonesia
| | - Bernd Wittmann
- Spectroscopy of Soft Matter, University of Bayreuth, 95440 Bayreuth, Germany
| | - Soichiro Seki
- Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Ritsuko Fujii
- Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
- Research Center for Artificial Photosynthesis, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Jürgen Köhler
- Spectroscopy of Soft Matter, University of Bayreuth, 95440 Bayreuth, Germany
- Bavarian Polymer Institute, University of Bayreuth, 95440 Bayreuth, Germany
- Bayreuther Institut für Makromolekülforschung (BIMF), 95440 Bayreuth, Germany
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8
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Preprocess dependence of optical properties of ensembles and single siphonaxanthin-containing major antenna from the marine green alga Codium fragile. Sci Rep 2022; 12:8461. [PMID: 35589761 PMCID: PMC9120457 DOI: 10.1038/s41598-022-11572-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/26/2022] [Indexed: 11/23/2022] Open
Abstract
The siphonaxanthin-siphonein-Chl-a/b-protein (SCP) is the light-harvesting complex of the marine alga Codium fragile. Its structure resembles that of the major light-harvesting complexes of higher plants, LHC II, yet it features a reversed Chl a:Chl b ratio and it accommodates other variants of carotenoids. We have recorded the fluorescence emission spectra and fluorescence lifetimes from ensembles and single SCP complexes for three different scenarios of handling the samples. While the data obtained from ensembles of SCP complexes yield equivalent results, those obtained from single SCP complexes featured significant differences as a function of the sample history. We ascribe this discrepancy to the different excitation intensities that have been used for ensemble and single complex spectroscopy, and conclude that the SCP complexes undergo an aging process during storage. This process is manifested as a lowering of energetic barriers within the protein, enabling thermal activation of conformational changes at room temperature. This in turn leads to the preferential population of a red-shifted state that features a significant decrease of the fluorescence lifetime.
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9
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Ruban A, Saccon F. Chlorophyll a De-Excitation Pathways in the LHCII antenna. J Chem Phys 2022; 156:070902. [DOI: 10.1063/5.0073825] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Alexander Ruban
- SBBS, Queen Mary University of London - Mile End Campus, United Kingdom
| | - Francesco Saccon
- School of Biological and Chemical Sciences, Queen Mary University of London - Mile End Campus, United Kingdom
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10
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Ruban AV, Wilson S. The Mechanism of Non-Photochemical Quenching in Plants: Localization and Driving Forces. PLANT & CELL PHYSIOLOGY 2021; 62:1063-1072. [PMID: 33351147 DOI: 10.1093/pcp/pcaa155] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 11/25/2020] [Indexed: 05/20/2023]
Abstract
Non-photochemical chlorophyll fluorescence quenching (NPQ) remains one of the most studied topics of the 21st century in photosynthesis research. Over the past 30 years, profound knowledge has been obtained on the molecular mechanism of NPQ in higher plants. First, the largely overlooked significance of NPQ in protecting the reaction center of photosystem II (RCII) against damage, and the ways to assess its effectiveness are highlighted. Then, the key in vivo signals that can monitor the life of the major NPQ component, qE, are presented. Finally, recent knowledge on the site of qE and the possible molecular events that transmit ΔpH into the conformational change in the major LHCII [the major trimeric light harvesting complex of photosystem II (PSII)] antenna complex are discussed. Recently, number of reports on Arabidopsis mutants lacking various antenna components of PSII confirmed that the in vivo site of qE rests within the major trimeric LHCII complex. Experiments on biochemistry, spectroscopy, microscopy and molecular modeling suggest an interplay between thylakoid membrane geometry and the dynamics of LHCII, the PsbS (PSII subunit S) protein and thylakoid lipids. The molecular basis for the qE-related conformational change in the thylakoid membrane, including the possible onset of a hydrophobic mismatch between LHCII and lipids, potentiated by PsbS protein, begins to unfold.
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Affiliation(s)
- Alexander V Ruban
- Department of Biochemistry, School of Biological and Chemical Sciences, Queen Mary University of London, Fogg Building, Mile End Road, London E1 4NS, UK
| | - Sam Wilson
- Department of Biochemistry, School of Biological and Chemical Sciences, Queen Mary University of London, Fogg Building, Mile End Road, London E1 4NS, UK
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11
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Ara AM, Ahmed MK, D'Haene S, van Roon H, Ilioaia C, van Grondelle R, Wahadoszamen M. Absence of far-red emission band in aggregated core antenna complexes. Biophys J 2021; 120:1680-1691. [PMID: 33675767 DOI: 10.1016/j.bpj.2021.02.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 01/31/2021] [Accepted: 02/22/2021] [Indexed: 10/22/2022] Open
Abstract
Reported herein is a Stark fluorescence spectroscopy study performed on photosystem II core antenna complexes CP43 and CP47 in their native and aggregated states. The systematic mathematical modeling of the Stark fluorescence spectra with the aid of conventional Liptay formalism revealed that induction of aggregation in both the core antenna complexes via detergent removal results in a single quenched species characterized by a remarkably broad and inhomogenously broadened emission lineshape peaking around 700 nm. The quenched species possesses a fairly large magnitude of charge-transfer character. From the analogy with the results from aggregated peripheral antenna complexes, the quenched species is thought to originate from the enhanced chlorophyll-chlorophyll interaction due to aggregation. However, in contrast, aggregation of both core antenna complexes did not produce a far-red emission band at ∼730 nm, which was identified in most of the aggregated peripheral antenna complexes. The 730-nm emission band of the aggregated peripheral antenna complexes was attributed to the enhanced chlorophyll-carotenoid (lutein1) interaction in the terminal emitter locus. Therefore, it is very likely that the no occurrence of the far-red band in the aggregated core antenna complexes is directly related to the absence of lutein1 in their structures. The absence of the far-red band also suggests the possibility that aggregation-induced conformational change of the core antenna complexes does not yield a chlorophyll-carotenoid interaction associated energy dissipation channel.
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Affiliation(s)
- Anjue Mane Ara
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Amsterdam, the Netherlands; Department of Physics, Jagannath University, Dhaka, Bangladesh
| | | | - Sandrine D'Haene
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Amsterdam, the Netherlands
| | - Henny van Roon
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Amsterdam, the Netherlands
| | - Cristian Ilioaia
- Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Rienk van Grondelle
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Amsterdam, the Netherlands
| | - Md Wahadoszamen
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, Amsterdam, the Netherlands; Department of Physics, University of Dhaka, Dhaka, Bangladesh.
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12
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Tu W, Wu L, Zhang C, Sun R, Wang L, Yang W, Yang C, Liu C. Neoxanthin affects the stability of the C 2 S 2 M 2 -type photosystem II supercomplexes and the kinetics of state transition in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:1724-1735. [PMID: 33085804 DOI: 10.1111/tpj.15033] [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: 06/17/2020] [Revised: 09/29/2020] [Accepted: 10/02/2020] [Indexed: 06/11/2023]
Abstract
Neoxanthin (Neo), which is only bound to the peripheral antenna proteins of photosystem (PS) II, is a conserved carotenoid in all green plants. It has been demonstrated that Neo plays an important role in photoprotection and its deficiency fails to impact LHCII stability in vitro and indoor plant growth in vivo. Whether Neo is involved in maintaining the PSII complex structure or adaptive mechanisms for the everchanging environment has not yet been elucidated. In this study, the role of Neo in maintaining the structure and function of the PSII-LHCII supercomplexes was studied using Neo deficient Arabidopsis mutants. Our results show that Neo deficiency had little effect on the electron transport capacity and the plant fitness, but the PSII-LHCII supercomplexes were significantly impacted by the lack of Neo. In the absence of Neo, the M-type LHCII trimer cannot effectively associate with the C2 S2 -type PSII-LHCII supercomplexes even in moderate light conditions. Interestingly, Neo deficiency also leads to decreased PSII protein phosphorylation but rapid transition from state 1 to state 2. We suggest that Neo might enforce the interactions between LHCII and the minor antennas and that the absence of Neo makes M-type LHCII disassociate from the PSII complex, leading to the disassembly of the PSII-LHCII C2 S2 M2 supercomplexes, which results in alterations in the phosphorylation patterns of the thylakoid photosynthetic proteins and the kinetics of state transition.
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Affiliation(s)
- Wenfeng Tu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Lishuan Wu
- Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chunyan Zhang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Ruixue Sun
- Qingdao Institute, Shanghai Institute of Technological Physics, Chinese Academy of Sciences, Qingdao, 264000, China
| | - Liangsheng Wang
- Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenqiang Yang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chunhong Yang
- Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Cheng Liu
- Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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13
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Saccon F, Durchan M, Polívka T, Ruban AV. The robustness of the terminal emitter site in major LHCII complexes controls xanthophyll function during photoprotection. Photochem Photobiol Sci 2020; 19:1308-1318. [PMID: 32815966 DOI: 10.1039/d0pp00174k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Xanthophylls in light harvesting complexes perform a number of functions ranging from structural support to light-harvesting and photoprotection. In the major light harvesting complex of photosystem II in plants (LHCII), the innermost xanthophyll binding pockets are occupied by lutein molecules. The conservation of these sites within the LHC protein family suggests their importance in LHCII functionality. In the present work, we induced the photoprotective switch in LHCII isolated from the Arabidopsis mutant npq1lut2, where the lutein molecules are exchanged with violaxanthin. Despite the differences in the energetics of the pigments and the impairment of chlorophyll fluorescence quenching in vivo, we show that isolated complexes containing violaxanthin are still able to induce the quenching switch to a similar extent to wild type LHCII monomers. Moreover, the same spectroscopic changes take place, which suggest the involvement of the terminal emitter site (L1) in energy dissipation in both complexes. These results indicate the robust nature of the L1 xanthophyll binding domain in LHCII, where protein structural cues are the major determinant of the function of the bound carotenoid.
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Affiliation(s)
- Francesco Saccon
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road E1 4NS, London, UK.
| | - Milan Durchan
- University of South Bohemia, Institute of Physics, Faculty of Science, České Budějovice, Czech Republic
| | - Tomáš Polívka
- University of South Bohemia, Institute of Physics, Faculty of Science, České Budějovice, Czech Republic
| | - Alexander V Ruban
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road E1 4NS, London, UK.
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14
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Photoprotective Role of Neoxanthin in Plants and Algae. Molecules 2020; 25:molecules25204617. [PMID: 33050573 PMCID: PMC7587190 DOI: 10.3390/molecules25204617] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 11/17/2022] Open
Abstract
Light is a paramount parameter driving photosynthesis. However, excessive irradiance leads to the formation of reactive oxygen species that cause cell damage and hamper the growth of photosynthetic organisms. Xanthophylls are key pigments involved in the photoprotective response of plants and algae to excessive light. Of particular relevance is the operation of xanthophyll cycles (XC) leading to the formation of de-epoxidized molecules with energy dissipating capacities. Neoxanthin, found in plants and algae in two different isomeric forms, is involved in the light stress response at different levels. This xanthophyll is not directly involved in XCs and the molecular mechanisms behind its photoprotective activity are yet to be fully resolved. This review comprehensively addresses the photoprotective role of 9′-cis-neoxanthin, the most abundant neoxanthin isomer, and one of the major xanthophyll components in plants’ photosystems. The light-dependent accumulation of all-trans-neoxanthin in photosynthetic cells was identified exclusively in algae of the order Bryopsidales (Chlorophyta), that lack a functional XC. A putative photoprotective model involving all-trans-neoxanthin is discussed.
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15
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Saccon F, Durchan M, Bína D, Duffy CD, Ruban AV, Polívka T. A Protein Environment-Modulated Energy Dissipation Channel in LHCII Antenna Complex. iScience 2020; 23:101430. [PMID: 32818906 PMCID: PMC7452274 DOI: 10.1016/j.isci.2020.101430] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/19/2020] [Accepted: 07/31/2020] [Indexed: 12/14/2022] Open
Abstract
The major light-harvesting complex of photosystem II (LHCII) is the main contributor to sunlight energy harvesting in plants. The flexible design of LHCII underlies a photoprotective mechanism whereby this complex switches to a dissipative state in response to high light stress, allowing the rapid dissipation of excess excitation energy (non-photochemical quenching, NPQ). In this work, we locked single LHCII trimers in a quenched conformation after immobilization of the complexes in polyacrylamide gels to impede protein interactions. A comparison of their pigment excited-state dynamics with quenched LHCII aggregates in buffer revealed the presence of a new spectral band at 515 nm arising after chlorophyll excitation. This is suggested to be the signature of a carotenoid excited state, linked to the quenching of chlorophyll singlet excited states. Our data highlight the marked sensitivity of pigment excited-state dynamics in LHCII to structural changes induced by the environment.
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Affiliation(s)
- Francesco Saccon
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, E1 4NS London, UK
| | - Milan Durchan
- University of South Bohemia, Institute of Physics, Faculty of Science, České Budějovice, Czech Republic
- Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, České Budějovice, Czech Republic
| | - David Bína
- University of South Bohemia, Institute of Chemistry, Faculty of Science, České Budějovice, Czech Republic
- Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, České Budějovice, Czech Republic
| | - Christopher D.P. Duffy
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, E1 4NS London, UK
| | - Alexander V. Ruban
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, E1 4NS London, UK
| | - Tomáš Polívka
- University of South Bohemia, Institute of Physics, Faculty of Science, České Budějovice, Czech Republic
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16
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Kim E, Kawakami K, Sato R, Ishii A, Minagawa J. Photoprotective Capabilities of Light-Harvesting Complex II Trimers in the Green Alga Chlamydomonas reinhardtii. J Phys Chem Lett 2020; 11:7755-7761. [PMID: 32822182 DOI: 10.1021/acs.jpclett.0c02098] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Major light-harvesting complex (LHCII) trimers in plants induce the thermal dissipation of absorbed excitation energy against photooxidative damage under excess light conditions. LHCII trimers in green algae have been thought to be incapable of energy dissipation without additional quencher proteins, although LHCIIs in plants and green algae are homologous. In this study, we investigated the energy-dissipative capabilities of four distinct types of LHCII trimers isolated from the model green alga Chlamydomonas reinhardtii using spectroscopic analysis. Our results revealed that the LHCII trimers possessing LHCII type II (LHCBM5) and LHCII type IV (LHCBM1) had efficient energy-dissipative capabilities, whereas LHCII type I (LHCBM3/4/6/8/9) and type III (LHCBM2/7) did not. On the basis of the amino acid sequences of LHCBM5 and LHCBM1 compared with the other LHCBMs, we propose that positively charged extra N-terminal amino acid residues mediate the interactions between LHCII trimers to form energy-dissipative states.
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Affiliation(s)
- Eunchul Kim
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan
| | - Keisuke Kawakami
- Research Center for Artificial Photosynthesis, Osaka City University, 3-3-138, Osaka, Japan
| | - Ryoichi Sato
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Asako Ishii
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki 444-8585, Japan
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17
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Li H, Wang Y, Ye M, Li S, Li D, Ren H, Wang M, Du L, Li H, Veglia G, Gao J, Weng Y. Dynamical and allosteric regulation of photoprotection in light harvesting complex II. Sci China Chem 2020; 63:1121-1133. [PMID: 33163014 DOI: 10.1007/s11426-020-9771-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Major light-harvesting complex of photosystem II (LHCII) plays a dual role in light-harvesting and excited energy dissipation to protect photodamage from excess energy. The regulatory switch is induced by increased acidity, temperature or both. However, the molecular origin of the protein dynamics at the atomic level is still unknown. We carried out temperature-jump time-resolved infrared spectroscopy and molecular dynamics simulations to determine the energy quenching dynamics and conformational changes of LHCII trimers. We found that the spontaneous formation of a pair of local α-helices from the 310-helix E/loop and the C-terminal coil of the neighboring monomer, in response to the increased environmental temperature and/or acidity, induces a scissoring motion of transmembrane helices A and B, shifting the conformational equilibrium to a more open state, with an increased angle between the associated carotenoids. The dynamical allosteric conformation change leads to close contacts between the first excited state of carotenoid lutein 1 and chlorophyll pigments, facilitating the fluorescence quenching. Based on these results, we suggest a unified mechanism by which the LHCII trimer controls the dissipation of excess excited energy in response to increased temperature and acidity, as an intrinsic result of intense sun light in plant photosynthesis.
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Affiliation(s)
- Hao Li
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingjie Wang
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
- Shenzhen Bay Laboratory, Shenzhen 518055, China
| | - Manping Ye
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Shanshan Li
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Deyong Li
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Haisheng Ren
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mohan Wang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Luchao Du
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Heng Li
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Gianluigi Veglia
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jiali Gao
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455, USA
- Shenzhen Bay Laboratory, Shenzhen 518055, China
- Laboratory of Computational Chemistry and Drug Design, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Yuxiang Weng
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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18
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Ostroumov EE, Götze JP, Reus M, Lambrev PH, Holzwarth AR. Characterization of fluorescent chlorophyll charge-transfer states as intermediates in the excited state quenching of light-harvesting complex II. PHOTOSYNTHESIS RESEARCH 2020; 144:171-193. [PMID: 32307623 DOI: 10.1007/s11120-020-00745-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 03/31/2020] [Indexed: 05/20/2023]
Abstract
Light-harvesting complex II (LHCII) is the major antenna complex in higher plants and green algae. It has been suggested that a major part of the excited state energy dissipation in the so-called "non-photochemical quenching" (NPQ) is located in this antenna complex. We have performed an ultrafast kinetics study of the low-energy fluorescent states related to quenching in LHCII in both aggregated and the crystalline form. In both sample types the chlorophyll (Chl) excited states of LHCII are strongly quenched in a similar fashion. Quenching is accompanied by the appearance of new far-red (FR) fluorescence bands from energetically low-lying Chl excited states. The kinetics of quenching, its temperature dependence down to 4 K, and the properties of the FR-emitting states are very similar both in LHCII aggregates and in the crystal. No such FR-emitting states are found in unquenched trimeric LHCII. We conclude that these states represent weakly emitting Chl-Chl charge-transfer (CT) states, whose formation is part of the quenching process. Quantum chemical calculations of the lowest energy exciton and CT states, explicitly including the coupling to the specific protein environment, provide detailed insight into the chemical nature of the CT states and the mechanism of CT quenching. The experimental data combined with the results of the calculations strongly suggest that the quenching mechanism consists of a sequence of two proton-coupled electron transfer steps involving the three quenching center Chls 610/611/612. The FR-emitting CT states are reaction intermediates in this sequence. The polarity-controlled internal reprotonation of the E175/K179 aa pair is suggested as the switch controlling quenching. A unified model is proposed that is able to explain all known conditions of quenching or non-quenching of LHCII, depending on the environment without invoking any major conformational changes of the protein.
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Affiliation(s)
- Evgeny E Ostroumov
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany
- Quantum Matter Institute, University of British Columbia, 2355 East Mall, Vancouver, V6T 1Z1, Canada
| | - Jan P Götze
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany
- Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, 14195, Berlin, Germany
| | - Michael Reus
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany
| | - Petar H Lambrev
- Biological Research Centre, Temesvári krt. 62, Szeged, 6726, Hungary
| | - Alfred R Holzwarth
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim a. d. Ruhr, Germany.
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19
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Mascoli V, Liguori N, Xu P, Roy LM, van Stokkum IH, Croce R. Capturing the Quenching Mechanism of Light-Harvesting Complexes of Plants by Zooming in on the Ensemble. Chem 2019. [DOI: 10.1016/j.chempr.2019.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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20
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Macroorganisation and flexibility of thylakoid membranes. Biochem J 2019; 476:2981-3018. [DOI: 10.1042/bcj20190080] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 09/19/2019] [Accepted: 10/03/2019] [Indexed: 02/07/2023]
Abstract
Abstract
The light reactions of photosynthesis are hosted and regulated by the chloroplast thylakoid membrane (TM) — the central structural component of the photosynthetic apparatus of plants and algae. The two-dimensional and three-dimensional arrangement of the lipid–protein assemblies, aka macroorganisation, and its dynamic responses to the fluctuating physiological environment, aka flexibility, are the subject of this review. An emphasis is given on the information obtainable by spectroscopic approaches, especially circular dichroism (CD). We briefly summarise the current knowledge of the composition and three-dimensional architecture of the granal TMs in plants and the supramolecular organisation of Photosystem II and light-harvesting complex II therein. We next acquaint the non-specialist reader with the fundamentals of CD spectroscopy, recent advances such as anisotropic CD, and applications for studying the structure and macroorganisation of photosynthetic complexes and membranes. Special attention is given to the structural and functional flexibility of light-harvesting complex II in vitro as revealed by CD and fluorescence spectroscopy. We give an account of the dynamic changes in membrane macroorganisation associated with the light-adaptation of the photosynthetic apparatus and the regulation of the excitation energy flow by state transitions and non-photochemical quenching.
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21
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Saccon F, Durchan M, Kaňa R, Prášil O, Ruban AV, Polívka T. Spectroscopic Properties of Violaxanthin and Lutein Triplet States in LHCII are Independent of Carotenoid Composition. J Phys Chem B 2019; 123:9312-9320. [DOI: 10.1021/acs.jpcb.9b06293] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Francesco Saccon
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, E1 4NS London, U.K
| | - Milan Durchan
- Institute of Physics, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | - Radek Kaňa
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, 379 81 Třeboň, Czech Republic
| | - Ondřej Prášil
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Opatovický mlýn, 379 81 Třeboň, Czech Republic
| | - Alexander V. Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, E1 4NS London, U.K
| | - Tomáš Polívka
- Institute of Physics, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic
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22
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Kuthanová Trsková E, Bína D, Santabarbara S, Sobotka R, Kaňa R, Belgio E. Isolation and characterization of CAC antenna proteins and photosystem I supercomplex from the cryptophytic alga Rhodomonas salina. PHYSIOLOGIA PLANTARUM 2019; 166:309-319. [PMID: 30677144 DOI: 10.1111/ppl.12928] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
In the present paper, we report an improved method combining sucrose density gradient with ion-exchange chromatography for the isolation of pure chlorophyll a/c antenna proteins from the model cryptophytic alga Rhodomonas salina. Antennas were used for in vitro quenching experiments in the absence of xanthophylls, showing that protein aggregation is a plausible mechanism behind non-photochemical quenching in R. salina. From sucrose gradient, it was also possible to purify a functional photosystem I supercomplex, which was in turn characterized by steady-state and time-resolved fluorescence spectroscopy. R. salina photosystem I showed a remarkably fast photochemical trapping rate, similar to what recently reported for other red clade algae such as Chromera velia and Phaeodactylum tricornutum. The method reported therefore may also be suitable for other still partially unexplored algae, such as cryptophytes.
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Affiliation(s)
- Eliška Kuthanová Trsková
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 379 81, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice, 370 05, České Budějovice, Czech Republic
| | - David Bína
- Faculty of Science, University of South Bohemia in České Budějovice, 370 05, České Budějovice, Czech Republic
- Institute of Plant Molecular Biology, Biology Centre CAS, 370 05, České Budějovice, Czech Republic
| | - Stefano Santabarbara
- Photosynthesis Research Unit, Centro Studi sulla Biologia Cellulare e Molecolare delle Piante, 20133, Milan, Italy
| | - Roman Sobotka
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 379 81, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice, 370 05, České Budějovice, Czech Republic
| | - Radek Kaňa
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 379 81, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice, 370 05, České Budějovice, Czech Republic
| | - Erica Belgio
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 379 81, Třeboň, Czech Republic
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23
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Adams PG, Vasilev C, Hunter CN, Johnson MP. Correlated fluorescence quenching and topographic mapping of Light-Harvesting Complex II within surface-assembled aggregates and lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2018; 1859:1075-1085. [PMID: 29928860 PMCID: PMC6135645 DOI: 10.1016/j.bbabio.2018.06.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 06/11/2018] [Accepted: 06/15/2018] [Indexed: 01/30/2023]
Abstract
Light-Harvesting Complex II (LHCII) is a chlorophyll-protein antenna complex that efficiently absorbs solar energy and transfers electronic excited states to photosystems I and II. Under excess light intensity LHCII can adopt a photoprotective state in which excitation energy is safely dissipated as heat, a process known as Non-Photochemical Quenching (NPQ). In vivo NPQ is triggered by combinatorial factors including transmembrane ΔpH, PsbS protein and LHCII-bound zeaxanthin, leading to dramatically shortened LHCII fluorescence lifetimes. In vitro, LHCII in detergent solution or in proteoliposomes can reversibly adopt an NPQ-like state, via manipulation of detergent/protein ratio, lipid/protein ratio, pH or pressure. Previous spectroscopic investigations revealed changes in exciton dynamics and protein conformation that accompany quenching, however, LHCII-LHCII interactions have not been extensively studied. Here, we correlated fluorescence lifetime imaging microscopy (FLIM) and atomic force microscopy (AFM) of trimeric LHCII adsorbed to mica substrates and manipulated the environment to cause varying degrees of quenching. AFM showed that LHCII self-assembled onto mica forming 2D-aggregates (25-150 nm width). FLIM determined that LHCII in these aggregates were in a quenched state, with much lower fluorescence lifetimes (~0.25 ns) compared to free LHCII in solution (2.2-3.9 ns). LHCII-LHCII interactions were disrupted by thylakoid lipids or phospholipids, leading to intermediate fluorescent lifetimes (0.6-0.9 ns). To our knowledge, this is the first in vitro correlation of nanoscale membrane imaging with LHCII quenching. Our findings suggest that lipids could play a key role in modulating the extent of LHCII-LHCII interactions within the thylakoid membrane and so the propensity for NPQ activation.
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Affiliation(s)
- Peter G Adams
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK; Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Cvetelin Vasilev
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
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24
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Ruban AV. Light harvesting control in plants. FEBS Lett 2018; 592:3030-3039. [PMID: 29797317 DOI: 10.1002/1873-3468.13111] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 04/30/2018] [Accepted: 05/18/2018] [Indexed: 01/02/2023]
Abstract
In 1991, my colleagues and I published a hypothesis article that proposed a mechanism that controls light harvesting in plants and protects them against photodamage. The major light harvesting complex, LHCII, was suggested to undergo aggregation upon exposure of the plant to damaging levels of light. Aggregated LHCII was found to be much less efficient in light harvesting, as it promptly dissipated absorbed energy into heat, possessing a very low chlorophyll fluorescence yield. Nonphotochemical quenching (NPQ) is a term coined to describe this reduction in chlorophyll fluorescence yield. This article is a story of how the hypothesis that LHCII aggregation is involved in NPQ is developed into a model that is now becoming broadly accepted by the research community.
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Affiliation(s)
- Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
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25
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Shibata Y, Mohamed A, Taniyama K, Kanatani K, Kosugi M, Fukumura H. Red shift in the spectrum of a chlorophyll species is essential for the drought-induced dissipation of excess light energy in a poikilohydric moss, Bryum argenteum. PHOTOSYNTHESIS RESEARCH 2018; 136:229-243. [PMID: 29124652 DOI: 10.1007/s11120-017-0461-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 10/27/2017] [Indexed: 06/07/2023]
Abstract
Some mosses are extremely tolerant of drought stress. Their high drought tolerance relies on their ability to effectively dissipate absorbed light energy to heat under dry conditions. The energy dissipation mechanism in a drought-tolerant moss, Bryum argenteum, has been investigated using low-temperature picosecond time-resolved fluorescence spectroscopy. The results are compared between moss thalli samples harvested in Antarctica and in Japan. Both samples show almost the same quenching properties, suggesting an identical drought tolerance mechanism for the same species with two completely different habitats. A global target analysis was applied to a large set of data on the fluorescence-quenching dynamics for the 430-nm (chlorophyll-a selective) and 460-nm (chlorophyll-b and carotenoid selective) excitations in the temperature region from 5 to 77 K. This analysis strongly suggested that the quencher is formed in the major peripheral antenna of photosystem II, whose emission spectrum is significantly broadened and red-shifted in its quenched form. Two emission components at around 717 and 725 nm were assigned to photosystem I (PS I). The former component at around 717 nm is mildly quenched and probably bound to the PS I core complex, while the latter at around 725 nm is probably bound to the light-harvesting complex. The dehydration treatment caused a blue shift of the PS I emission peak via reduction of the exciton energy flow to the pigment responsible for the 725 nm band.
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Affiliation(s)
- Yutaka Shibata
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki Aza Aoba, Aoba-Ku, Sendai, 980-8578, Japan.
| | - Ahmed Mohamed
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki Aza Aoba, Aoba-Ku, Sendai, 980-8578, Japan
- Institut national de la recherche scientifique (INRS-EMT), Varennes, QC, J3X 1S2, Canada
| | - Koichiro Taniyama
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki Aza Aoba, Aoba-Ku, Sendai, 980-8578, Japan
| | - Kentaro Kanatani
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki Aza Aoba, Aoba-Ku, Sendai, 980-8578, Japan
| | - Makiko Kosugi
- Department of Biological Science, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-Ku, Tokyo, 112-8551, Japan
| | - Hiroshi Fukumura
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki Aza Aoba, Aoba-Ku, Sendai, 980-8578, Japan
- National Institute of Technology, 4-16-1 Ayashi-chuo, Aoba-ku, Sendai, 989-3128, Japan
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26
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Magyar M, Sipka G, Kovács L, Ughy B, Zhu Q, Han G, Špunda V, Lambrev PH, Shen JR, Garab G. Rate-limiting steps in the dark-to-light transition of Photosystem II - revealed by chlorophyll-a fluorescence induction. Sci Rep 2018; 8:2755. [PMID: 29426901 DOI: 10.1038/s41598-41018-21195-41592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 01/31/2018] [Indexed: 05/28/2023] Open
Abstract
Photosystem II (PSII) catalyses the photoinduced oxygen evolution and, by producing reducing equivalents drives, in concert with PSI, the conversion of carbon dioxide to sugars. Our knowledge about the architecture of the reaction centre (RC) complex and the mechanisms of charge separation and stabilisation is well advanced. However, our understanding of the processes associated with the functioning of RC is incomplete: the photochemical activity of PSII is routinely monitored by chlorophyll-a fluorescence induction but the presently available data are not free of controversy. In this work, we examined the nature of gradual fluorescence rise of PSII elicited by trains of single-turnover saturating flashes (STSFs) in the presence of a PSII inhibitor, permitting only one stable charge separation. We show that a substantial part of the fluorescence rise originates from light-induced processes that occur after the stabilisation of charge separation, induced by the first STSF; the temperature-dependent relaxation characteristics suggest the involvement of conformational changes in the additional rise. In experiments using double flashes with variable waiting times (∆τ) between them, we found that no rise could be induced with zero or short ∆τ, the value of which depended on the temperature - revealing a previously unknown rate-limiting step in PSII.
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Affiliation(s)
- Melinda Magyar
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary
| | - Gábor Sipka
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary
| | - László Kovács
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary
| | - Bettina Ughy
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary
| | - Qingjun Zhu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany the Chinese Academy of Sciences, Beijing, 100093, China
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany the Chinese Academy of Sciences, Beijing, 100093, China
| | - Vladimír Špunda
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, CZ-710 00, Ostrava, Czech Republic
- Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic
| | - Petar H Lambrev
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany the Chinese Academy of Sciences, Beijing, 100093, China
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, 1-1, Naka 3-chome, Tsushima, Okayama, 700-8530, Japan
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Temesvári körút 62, H-6726, Szeged, Hungary.
- Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, CZ-710 00, Ostrava, Czech Republic.
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27
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Rate-limiting steps in the dark-to-light transition of Photosystem II - revealed by chlorophyll-a fluorescence induction. Sci Rep 2018; 8:2755. [PMID: 29426901 PMCID: PMC5807364 DOI: 10.1038/s41598-018-21195-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 01/31/2018] [Indexed: 12/21/2022] Open
Abstract
Photosystem II (PSII) catalyses the photoinduced oxygen evolution and, by producing reducing equivalents drives, in concert with PSI, the conversion of carbon dioxide to sugars. Our knowledge about the architecture of the reaction centre (RC) complex and the mechanisms of charge separation and stabilisation is well advanced. However, our understanding of the processes associated with the functioning of RC is incomplete: the photochemical activity of PSII is routinely monitored by chlorophyll-a fluorescence induction but the presently available data are not free of controversy. In this work, we examined the nature of gradual fluorescence rise of PSII elicited by trains of single-turnover saturating flashes (STSFs) in the presence of a PSII inhibitor, permitting only one stable charge separation. We show that a substantial part of the fluorescence rise originates from light-induced processes that occur after the stabilisation of charge separation, induced by the first STSF; the temperature-dependent relaxation characteristics suggest the involvement of conformational changes in the additional rise. In experiments using double flashes with variable waiting times (∆τ) between them, we found that no rise could be induced with zero or short ∆τ, the value of which depended on the temperature - revealing a previously unknown rate-limiting step in PSII.
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28
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Janik E, Bednarska J, Sowinski K, Luchowski R, Zubik M, Grudzinski W, Gruszecki WI. Light-induced formation of dimeric LHCII. PHOTOSYNTHESIS RESEARCH 2017; 132:265-276. [PMID: 28425025 PMCID: PMC5443882 DOI: 10.1007/s11120-017-0387-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 04/11/2017] [Indexed: 05/14/2023]
Abstract
It emerges from numerous experiments that LHCII, the major photosynthetic antenna complex of plants, can appear not only in the trimeric or monomeric states but also as a dimer. We address the problem whether the dimeric form of the complex is just a simple intermediate element of the trimer-monomer transformation or if it can also be a physiologically relevant molecular organization form? Dimers of LHCII were analyzed with application of native electrophoresis, time-resolved fluorescence spectroscopy, and fluorescence correlation spectroscopy. The results reveal the appearance of two types of LHCII dimers: one formed by the dissociation of one monomer from the trimeric structure and the other formed by association of monomers into a distinctively different molecular organizational form, characterized by a high rate of chlorophyll excitation quenching. The hypothetical structure of such an energy quencher is proposed. The high light-induced LHCII dimerization is discussed as a potential element of the photoprotective response in plants.
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Affiliation(s)
- Ewa Janik
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, Pl. Marii Curie-Sklodowskiej 1, 20-031 Lublin, Poland
- Department of Cell Biology, Institute of Biology and Biochemistry, Maria Curie-Sklodowska University, ul. Akademicka 19, 20-033 Lublin, Poland
| | - Joanna Bednarska
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, Pl. Marii Curie-Sklodowskiej 1, 20-031 Lublin, Poland
- Department of Medicine, Imperial College London, Du Cane Road, London, W12 0NN UK
| | - Karol Sowinski
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, Pl. Marii Curie-Sklodowskiej 1, 20-031 Lublin, Poland
- Chair and Department of Synthesis and Chemical Technology of Pharmaceutical Substances, Faculty of Pharmacy, Medical University, ul. Chodzki 4a, 20-093 Lublin, Poland
| | - Rafal Luchowski
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, Pl. Marii Curie-Sklodowskiej 1, 20-031 Lublin, Poland
| | - Monika Zubik
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, Pl. Marii Curie-Sklodowskiej 1, 20-031 Lublin, Poland
- Department of Metrology and Modelling of Agrophysical Processes, Institute of Agrophysics of Polish Academy of Sciences, ul. Doswiadczalna 4, 20-290 Lublin, Poland
| | - Wojciech Grudzinski
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, Pl. Marii Curie-Sklodowskiej 1, 20-031 Lublin, Poland
| | - Wieslaw I. Gruszecki
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, Pl. Marii Curie-Sklodowskiej 1, 20-031 Lublin, Poland
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29
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Disentangling protein and lipid interactions that control a molecular switch in photosynthetic light harvesting. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:40-47. [DOI: 10.1016/j.bbamem.2016.10.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Revised: 09/30/2016] [Accepted: 10/21/2016] [Indexed: 11/18/2022]
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30
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Karthik S, Suriyaprabha R, Balu KS, Manivasakan P, Rajendran V. Influence of ball milling on the particle size and antimicrobial properties of
Tridax procumbens
leaf nanoparticles. IET Nanobiotechnol 2016; 11:12-17. [DOI: 10.1049/iet-nbt.2016.0028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Subramani Karthik
- Centre for Nano Science and TechnologyK. S. Rangasamy College of TechnologyTiruchengode 637 215Tamil NaduIndia
| | - Rangaraj Suriyaprabha
- Centre for Nano Science and TechnologyK. S. Rangasamy College of TechnologyTiruchengode 637 215Tamil NaduIndia
| | | | - Palanisamy Manivasakan
- Centre for Nano Science and TechnologyK. S. Rangasamy College of TechnologyTiruchengode 637 215Tamil NaduIndia
| | - Venkatachalam Rajendran
- Centre for Nano Science and TechnologyK. S. Rangasamy College of TechnologyTiruchengode 637 215Tamil NaduIndia
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31
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Santabarbara S, Zubik M, Remelli W, Zucchelli G, Gruszecki WI. Two wavelength-dependent mechanisms of sensitisation of light-induced quenching in the isolated light-harvesting complex II. FEBS Lett 2016; 590:2549-57. [PMID: 27364980 DOI: 10.1002/1873-3468.12279] [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: 03/30/2016] [Revised: 05/30/2016] [Accepted: 06/24/2016] [Indexed: 11/06/2022]
Abstract
The efficiency of visible light in inducing fluorescence quenching in the isolated light-harvesting complex II (LHCII) of higher plants is investigated by action spectroscopy in the visible portion of photosynthetic active radiation. The efficiency spectrum displays a relatively homogenous quenching yield across the most intense electronic transitions of the chlorophyll a and carotenoid pigments, indicating that quenching proceeds from the equilibrated state of the complex. Larger yields are observed in the 510-640-nm window, where weak transitions of LHCII-bound chromophores occur. This observation is interpreted in terms of an additional quenching sensitisation process mediated by these electronic transitions.
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Affiliation(s)
| | - Monika Zubik
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, Lublin, Poland
| | - William Remelli
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Milano, Italy
| | - Giuseppe Zucchelli
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Milano, Italy
| | - Wieslaw I Gruszecki
- Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, Lublin, Poland
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32
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LHCSR1 induces a fast and reversible pH-dependent fluorescence quenching in LHCII in Chlamydomonas reinhardtii cells. Proc Natl Acad Sci U S A 2016; 113:7673-8. [PMID: 27335457 DOI: 10.1073/pnas.1605380113] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To avoid photodamage, photosynthetic organisms are able to thermally dissipate the energy absorbed in excess in a process known as nonphotochemical quenching (NPQ). Although NPQ has been studied extensively, the major players and the mechanism of quenching remain debated. This is a result of the difficulty in extracting molecular information from in vivo experiments and the absence of a validation system for in vitro experiments. Here, we have created a minimal cell of the green alga Chlamydomonas reinhardtii that is able to undergo NPQ. We show that LHCII, the main light harvesting complex of algae, cannot switch to a quenched conformation in response to pH changes by itself. Instead, a small amount of the protein LHCSR1 (light-harvesting complex stress related 1) is able to induce a large, fast, and reversible pH-dependent quenching in an LHCII-containing membrane. These results strongly suggest that LHCSR1 acts as pH sensor and that it modulates the excited state lifetimes of a large array of LHCII, also explaining the NPQ observed in the LHCSR3-less mutant. The possible quenching mechanisms are discussed.
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33
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Ruban AV. Nonphotochemical Chlorophyll Fluorescence Quenching: Mechanism and Effectiveness in Protecting Plants from Photodamage. PLANT PHYSIOLOGY 2016; 170:1903-16. [PMID: 26864015 PMCID: PMC4825125 DOI: 10.1104/pp.15.01935] [Citation(s) in RCA: 503] [Impact Index Per Article: 62.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/01/2016] [Indexed: 05/18/2023]
Abstract
We review the mechanism underlying nonphotochemical chlorophyll fluorescence quenching (NPQ) and its role in protecting plants against photoinhibition. This review includes an introduction to this phenomenon, a brief history of major milestones in our understanding of NPQ, definitions, and a discussion of quantitative measurements of NPQ We discuss the current knowledge and unknown aspects in the NPQ scenario, including the following: ΔpH, the proton gradient (trigger); light-harvesting complex II (LHCII), PSII light harvesting antenna (site); and changes in the antenna induced by ΔpH (change), which lead to the creation of the quencher We conclude that the minimum requirements for NPQ in vivo are ΔpH, LHCII complexes, and the PsbS protein. We highlight the most important unknown in the NPQ scenario, the mechanism by which PsbS acts upon the LHCII antenna. Finally, we describe a novel, emerging technology for assessing the photoprotective "power" of NPQ and the important findings obtained through this technology.
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Affiliation(s)
- Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
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34
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Enriquez MM, Akhtar P, Zhang C, Garab G, Lambrev PH, Tan HS. Energy transfer dynamics in trimers and aggregates of light-harvesting complex II probed by 2D electronic spectroscopy. J Chem Phys 2016; 142:212432. [PMID: 26049452 DOI: 10.1063/1.4919239] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The pathways and dynamics of excitation energy transfer between the chlorophyll (Chl) domains in solubilized trimeric and aggregated light-harvesting complex II (LHCII) are examined using two-dimensional electronic spectroscopy (2DES). The LHCII trimers and aggregates exhibit the unquenched and quenched excitonic states of Chl a, respectively. 2DES allows direct correlation of excitation and emission energies of coupled states over population time delays, hence enabling mapping of the energy flow between Chls. By the excitation of the entire Chl b Qy band, energy transfer from Chl b to Chl a states is monitored in the LHCII trimers and aggregates. Global analysis of the two-dimensional (2D) spectra reveals that energy transfer from Chl b to Chl a occurs on fast and slow time scales of 240-270 fs and 2.8 ps for both forms of LHCII. 2D decay-associated spectra resulting from the global analysis identify the correlation between Chl states involved in the energy transfer and decay at a given lifetime. The contribution of singlet-singlet annihilation on the kinetics of Chl energy transfer and decay is also modelled and discussed. The results show a marked change in the energy transfer kinetics in the time range of a few picoseconds. Owing to slow energy equilibration processes, long-lived intermediate Chl a states are present in solubilized trimers, while in aggregates, the population decay of these excited states is significantly accelerated, suggesting that, overall, the energy transfer within the LHCII complexes is faster in the aggregated state.
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Affiliation(s)
- Miriam M Enriquez
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Parveen Akhtar
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, Hungary
| | - Cheng Zhang
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, Hungary
| | - Petar H Lambrev
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, Hungary
| | - Howe-Siang Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
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35
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Bielczynski LW, Schansker G, Croce R. Effect of Light Acclimation on the Organization of Photosystem II Super- and Sub-Complexes in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2016; 7:105. [PMID: 26925068 PMCID: PMC4756287 DOI: 10.3389/fpls.2016.00105] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 01/20/2016] [Indexed: 05/18/2023]
Abstract
To survive under highly variable environmental conditions, higher plants have acquired a large variety of acclimation responses. Different strategies are used to cope with changes in light intensity with the common goal of modulating the functional antenna size of Photosystem II (PSII). Here we use a combination of biochemical and biophysical methods to study these changes in response to acclimation to high light (HL). After 2 h of exposure, a decrease in the amount of the large PSII supercomplexes is observed indicating that plants are already acclimating to HL at this stage. It is also shown that in HL the relative amount of antenna proteins decreases but this decrease is far less than the observed decrease of the functional antenna size, suggesting that part of the antenna present in the membranes in HL does not transfer energy efficiently to the reaction center. Finally, we observed LHCII monomers in all conditions. As the solubilization conditions used do not lead to monomerization of purified LHCII trimers, we should conclude that a population of LHCII monomers exists in the membrane. The relative amount of LHCII monomers strongly increases in plants acclimated to HL, while no changes in the trimer to monomer ratio are observed upon short exposure to stress.
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36
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Fox KF, Bricker WP, Lo C, Duffy CDP. Distortions of the Xanthophylls Caused by Interactions with Neighboring Pigments and the LHCII Protein Are Crucial for Studying Energy Transfer Pathways within the Complex. J Phys Chem B 2015; 119:15550-60. [DOI: 10.1021/acs.jpcb.5b08941] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- K. F. Fox
- The
School of Biological and Chemical Sciences, Queen Mary’s University of London, Mile End Road, London E1 4NS, England
| | - William P. Bricker
- Department
of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, 1 Brookings Drive, Saint Louis, Missouri 63130-4899, United States
| | - Cynthia Lo
- Department
of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, 1 Brookings Drive, Saint Louis, Missouri 63130-4899, United States
| | - C. D. P. Duffy
- The
School of Biological and Chemical Sciences, Queen Mary’s University of London, Mile End Road, London E1 4NS, England
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37
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Duffy CD, Ruban AV. Dissipative pathways in the photosystem-II antenna in plants. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 152:215-26. [DOI: 10.1016/j.jphotobiol.2015.09.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/07/2015] [Accepted: 09/11/2015] [Indexed: 10/23/2022]
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38
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Xu P, Tian L, Kloz M, Croce R. Molecular insights into Zeaxanthin-dependent quenching in higher plants. Sci Rep 2015; 5:13679. [PMID: 26323786 PMCID: PMC4555179 DOI: 10.1038/srep13679] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/03/2015] [Indexed: 11/14/2022] Open
Abstract
Photosynthetic organisms protect themselves from high-light stress by dissipating excess absorbed energy as heat in a process called non-photochemical quenching (NPQ). Zeaxanthin is essential for the full development of NPQ, but its role remains debated. The main discussion revolves around two points: where does zeaxanthin bind and does it quench? To answer these questions we have followed the zeaxanthin-dependent quenching from leaves to individual complexes, including supercomplexes. We show that small amounts of zeaxanthin are associated with the complexes, but in contrast to what is generally believed, zeaxanthin binding per se does not cause conformational changes in the complexes and does not induce quenching, not even at low pH. We show that in NPQ conditions zeaxanthin does not exchange for violaxanthin in the internal binding sites of the antennas but is located at the periphery of the complexes. These results together with the observation that the zeaxanthin-dependent quenching is active in isolated membranes, but not in functional supercomplexes, suggests that zeaxanthin is acting in between the complexes, helping to create/participating in a variety of quenching sites. This can explain why none of the antennas appears to be essential for NPQ and the multiple quenching mechanisms that have been observed in plants.
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Affiliation(s)
- Pengqi Xu
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam and LaserLab Amsterdam. De Boelelaan, 1081, 1081 HV, Amsterdam, The Netherlands
| | - Lijin Tian
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam and LaserLab Amsterdam. De Boelelaan, 1081, 1081 HV, Amsterdam, The Netherlands
| | - Miroslav Kloz
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam and LaserLab Amsterdam. De Boelelaan, 1081, 1081 HV, Amsterdam, The Netherlands
| | - Roberta Croce
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam and LaserLab Amsterdam. De Boelelaan, 1081, 1081 HV, Amsterdam, The Netherlands
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39
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van Oort B, van Grondelle R, van Stokkum IHM. A Hidden State in Light-Harvesting Complex II Revealed By Multipulse Spectroscopy. J Phys Chem B 2015; 119:5184-93. [PMID: 25815531 PMCID: PMC4500649 DOI: 10.1021/acs.jpcb.5b01335] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 03/23/2015] [Indexed: 11/28/2022]
Abstract
Light-harvesting complex II (LHCII) is pivotal both for collecting solar radiation for photosynthesis, and for protection against photodamage under high light intensities (via a process called nonphotochemical quenching, NPQ). Aggregation of LHCII is associated with fluorescence quenching, and is used as an in vitro model system of NPQ. However, there is no agreement on the nature of the quencher and on the validity of aggregation as a model system. Here, we use ultrafast multipulse spectroscopy to populate a quenched state in unquenched (unaggregated) LHCII. The state shows characteristic features of lutein and chlorophyll, suggesting that it is an excitonically coupled state between these two compounds. This state decays in approximately 10 ps, making it a strong competitor for photodamage and photochemical quenching. It is observed in trimeric and monomeric LHCII, upon re-excitation with pulses of different wavelengths and duration. We propose that this state is always present, but is scarcely populated under low light intensities. Under high light intensities it may become more accessible, e.g. by conformational changes, and then form a quenching channel. The same state may be the cause of fluorescence blinking observed in single-molecule spectroscopy of LHCII trimers, where a small subpopulation is in an energetically higher state where the pathway to the quencher opens up.
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Affiliation(s)
- Bart van Oort
- Department
of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
- Institute
for Lasers, Life and Biophotonics, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Rienk van Grondelle
- Department
of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
- Institute
for Lasers, Life and Biophotonics, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Ivo H. M. van Stokkum
- Department
of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
- Institute
for Lasers, Life and Biophotonics, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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40
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A megacomplex composed of both photosystem reaction centres in higher plants. Nat Commun 2015; 6:6675. [PMID: 25809225 DOI: 10.1038/ncomms7675] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 02/19/2015] [Indexed: 11/08/2022] Open
Abstract
Throughout the history of oxygen evolution, two types of photosystem reaction centres (PSI and PSII) have worked in a coordinated manner. The oxygen evolving centre is an integral part of PSII, and extracts an electron from water. PSI accepts the electron, and accumulates reducing power. Traditionally, PSI and PSII are thought to be spatially dispersed. Here, we show that about half of PSIIs are physically connected to PSIs in Arabidopsis thaliana. In the PSI-PSII complex, excitation energy is transferred efficiently between the two closely interacting reaction centres. PSII diverts excitation energy to PSI when PSII becomes closed-state in the PSI-PSII complex. The formation of PSI-PSII complexes is regulated by light conditions. Quenching of excess energy by PSI might be one of the physiological functions of PSI-PSII complexes.
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41
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Akhtar P, Dorogi M, Pawlak K, Kovács L, Bóta A, Kiss T, Garab G, Lambrev PH. Pigment interactions in light-harvesting complex II in different molecular environments. J Biol Chem 2015; 290:4877-4886. [PMID: 25525277 PMCID: PMC4335227 DOI: 10.1074/jbc.m114.607770] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 12/16/2014] [Indexed: 11/06/2022] Open
Abstract
Extraction of plant light-harvesting complex II (LHCII) from the native thylakoid membrane or from aggregates by the use of surfactants brings about significant changes in the excitonic circular dichroism (CD) spectrum and fluorescence quantum yield. To elucidate the cause of these changes, e.g. trimer-trimer contacts or surfactant-induced structural perturbations, we compared the CD spectra and fluorescence kinetics of LHCII aggregates, artificial and native LHCII-lipid membranes, and LHCII solubilized in different detergents or trapped in polymer gel. By this means we were able to identify CD spectral changes specific to LHCII-LHCII interactions, at (-)-437 and (+)-484 nm, and changes specific to the interaction with the detergent n-dodecyl-β-maltoside (β-DM) or membrane lipids, at (+)-447 and (-)-494 nm. The latter change is attributed to the conformational change of the LHCII-bound carotenoid neoxanthin, by analyzing the CD spectra of neoxanthin-deficient plant thylakoid membranes. The neoxanthin-specific band at (-)-494 nm was not pronounced in LHCII in detergent-free gels or solubilized in the α isomer of DM but was present when LHCII was reconstituted in membranes composed of phosphatidylcholine or plant thylakoid lipids, indicating that the conformation of neoxanthin is sensitive to the molecular environment. Neither the aggregation-specific CD bands, nor the surfactant-specific bands were positively associated with the onset of fluorescence quenching, which could be triggered without invoking such spectral changes. Significant quenching was not active in reconstituted LHCII proteoliposomes, whereas a high degree of energetic connectivity, depending on the lipid:protein ratio, in these membranes allows for efficient light harvesting.
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Affiliation(s)
- Parveen Akhtar
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and
| | - Márta Dorogi
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and
| | - Krzysztof Pawlak
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and
| | - László Kovács
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and
| | - Attila Bóta
- Hungarian Academy of Sciences, Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Magyar tudósok körútja 2, 1117 Budapest, Hungary
| | - Teréz Kiss
- Hungarian Academy of Sciences, Research Centre for Natural Sciences, Institute of Materials and Environmental Chemistry, Magyar tudósok körútja 2, 1117 Budapest, Hungary
| | - Győző Garab
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and
| | - Petar H Lambrev
- Hungarian Academy of Sciences, Biological Research Centre, Temesvári krt. 62, 6726 Szeged and.
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42
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Ruban AV. Evolution under the sun: optimizing light harvesting in photosynthesis. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:7-23. [PMID: 25336689 DOI: 10.1093/jxb/eru400] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The emergence and evolution of life on our planet was possible because the sun provides energy to our biosphere. Indeed, all life forms need energy for existence and proliferation in space and time. Light-energy conversion takes place in photosynthetic organisms that evolve in various environments featuring an impressive range of light intensities that span several orders of magnitude. This property is achieved by the evolution of mechanisms of efficient energy capture that involved development of antenna pigments and pigment-protein complexes as well as the emergence of various strategies on the organismal, cellular, and molecular levels to counteract the detrimental effects of high light intensity on the delicate photosynthetic apparatus. Darwin was one of the first to describe the behaviour of plants towards light. He noticed that some plants try to avoid full daylight and called this reaction paraheliotropism. However, it was only in the second half of the 20th century, when scientists began to discover the structure and molecular mechanisms of the photosynthetic machinery, that the reasons for paraheliotropisms became clear. This review explains the need for the evolution of light adaptations using the example of higher plants. The review focuses on short-term adaptation mechanisms that occur on the minute scale, showing that these processes are fast enough to track rapid fluctuations in light intensity and that they evolved to be effective, allowing for the expansion of plant habitats and promoting diversification and survival. Also introduced are the most recent developments in methods that enable quantification of the light intensities that can be tolerated by plants.
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Affiliation(s)
- Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, UK
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43
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Vasilev C, Johnson MP, Gonzales E, Wang L, Ruban A, Montano G, Cadby AJ, Hunter CN. Reversible switching between nonquenched and quenched states in nanoscale linear arrays of plant light-harvesting antenna complexes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:8481-90. [PMID: 24988144 PMCID: PMC4108477 DOI: 10.1021/la501483s] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 06/30/2014] [Indexed: 05/23/2023]
Abstract
A simple and robust nanolithographic method that allows sub-100 nm chemical patterning on a range of oxide surfaces was developed in order to fabricate nanoarrays of plant light-harvesting LHCII complexes. The site-specific immobilization and the preserved functionality of the LHCII complexes were confirmed by fluorescence emission spectroscopy. Nanopatterned LHCII trimers could be reversibly switched between fluorescent and quenched states by controlling the detergent concentration in the imaging buffer. A 3-fold quenching of the average fluorescence intensity was accompanied by a decrease in the average (amplitude-weighted) fluorescence lifetime from approximately 2.24 ns to approximately 0.4 ns, attributed to the intrinsic ability of LHCII to switch between fluorescent and quenched states upon changes in its conformational state. The nanopatterning methodology was extended by immobilizing a second protein, the enhanced green fluorescent protein (EGFP), onto LHCII-free areas of the chemically patterned surfaces. This very simple surface chemistry, which allows simultaneous selective immobilization and therefore sorting of the two types of protein molecules on the surface, is a key underpinning step toward the integration of LHCII into switchable biohybrid antenna constructs.
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Affiliation(s)
- Cvetelin Vasilev
- Department
of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, United Kingdom
| | - Matthew P. Johnson
- Department
of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, United Kingdom
| | - Edward Gonzales
- Center
for Integrated Nanotechnologies, Los Alamos
National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Lin Wang
- Department
of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, United Kingdom
- Department
of Physics and Astronomy, University of
Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, United Kingdom
| | - Alexander
V. Ruban
- School
of Biological and Chemical Sciences, Queen
Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Gabriel Montano
- Center
for Integrated Nanotechnologies, Los Alamos
National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Ashley J. Cadby
- Department
of Physics and Astronomy, University of
Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, United Kingdom
| | - C. Neil Hunter
- Department
of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, United Kingdom
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Krüger TP, Ilioaia C, Johnson MP, Ruban AV, van Grondelle R. Disentangling the low-energy states of the major light-harvesting complex of plants and their role in photoprotection. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1027-38. [DOI: 10.1016/j.bbabio.2014.02.014] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 02/10/2014] [Accepted: 02/12/2014] [Indexed: 11/28/2022]
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45
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Kell A, Feng X, Lin C, Yang Y, Li J, Reus M, Holzwarth AR, Jankowiak R. Charge-transfer character of the low-energy Chl a Q(y) absorption band in aggregated light harvesting complexes II. J Phys Chem B 2014; 118:6086-91. [PMID: 24838007 DOI: 10.1021/jp501735p] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
One of the key functions of the major light harvesting complex II (LHCII) of higher plants is to protect Photosystem II from photodamage at excessive light conditions in a process called "non-photochemical quenching" (NPQ). Using hole-burning (HB) spectroscopy, we investigated the nature of the low-energy absorption band in aggregated LHCII complexes - which are highly quenched and have been established as a good in vitro model for NPQ. Nonresonant holes reveal that the lowest energy state (located near 683.3 nm) is red-shifted by ~4 nm and significantly broader (by a factor of 4) as compared to nonaggregated trimeric LHCII. Resonant holes burned in the low-energy wing of the absorption spectrum (685-710 nm) showed a high electron-phonon (el-ph) coupling strength with a Huang-Rhys factor S of 3-4. This finding combined with the very low HB efficiency in the long-wavelength absorption tail is consistent with a dominant charge-transfer (CT) character of the lowest energy transition(s) in aggregated LHCII. The value of S decreases at shorter wavelengths (<685 nm), in agreement with previous studies (J. Pieper et al., J. Phys. Chem. B 1999, 103, 2422-2428), proving that the low-energy excitonic state is strongly mixed with the CT states. Our findings support the mechanistic model in which Chl-Chl CT states formed in aggregated LHCII are intermediates in the efficient excited state quenching process (M. G. Müller et al., Chem. Phys. Chem. 2010, 11, 1289-1296; Y. Miloslavina et al., FEBS Lett. 2008, 582, 3625-3631).
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Affiliation(s)
- Adam Kell
- Department of Chemistry and ‡Department of Physics, Kansas State University , Manhattan, Kansas 66505, United States
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46
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Duffy CDP, Pandit A, Ruban AV. Modeling the NMR signatures associated with the functional conformational switch in the major light-harvesting antenna of photosystem II in higher plants. Phys Chem Chem Phys 2014; 16:5571-80. [PMID: 24513782 DOI: 10.1039/c3cp54971b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The major photosystem II antenna complex, LHCII, possesses an intrinsic conformational switch linked to the formation of a photoprotective, excitation-quenching state. Recent solid state NMR experiments revealed that aggregation-induced quenching in (13)C-enriched LHCII from C. reinhardtii is associated with changes to the chemical shifts of three specific (13)C atoms in the Chla conjugated macrocycle. We performed DFT-based NMR calculations on the strongly-quenched crystal structure of LHCII (taken from spinach). We demonstrate that specific Chla-xanthophyll interactions in the quenched structure lead to changes in the Chla(13)C chemical shifts that are qualitatively similar to those observed by solid state NMR. We propose that these NMR changes are due to modulations in Chla-xanthophyll associations that occur due to a quenching-associated functional conformation change in the lutein and neoxanthin domains of LHCII. The combination of solid-state NMR and theoretical modeling is therefore a powerful tool for assessing functional conformational switching in the photosystem II antenna.
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Affiliation(s)
- Christopher D P Duffy
- The School of Biological and Chemical Science, Queen Mary, University of London, Mile End, London E1 4NS, UK.
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47
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Non-Photochemical Quenching Mechanisms in Intact Organisms as Derived from Ultrafast-Fluorescence Kinetic Studies. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2014. [DOI: 10.1007/978-94-017-9032-1_5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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48
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How Protein Disorder Controls Non-Photochemical Fluorescence Quenching. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2014. [DOI: 10.1007/978-94-017-9032-1_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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49
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Petrou K, Belgio E, Ruban AV. pH sensitivity of chlorophyll fluorescence quenching is determined by the detergent/protein ratio and the state of LHCII aggregation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:1533-9. [PMID: 24321504 DOI: 10.1016/j.bbabio.2013.11.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 11/22/2013] [Accepted: 11/26/2013] [Indexed: 12/31/2022]
Abstract
Here we show how the protein environment in terms of detergent concentration/protein aggregation state, affects the sensitivity to pH of isolated, native LHCII, in terms of chlorophyll fluorescence quenching. Three detergent concentrations (200, 20 and 6μM n-dodecyl β-d-maltoside) have been tested. It was found that at the detergent concentration of 6μM, low pH quenching of LHCII is close to the physiological response to lumen acidification possessing pK of 5.5. The analysis has been conducted both using arbitrary PAM fluorimetry measurements and chlorophyll fluorescence lifetime component analysis. The second led to the conclusion that the 3.5ns component lifetime corresponds to an unnatural state of LHCII, induced by the detergent used for solubilising the protein, whilst the 2ns component is rather the most representative lifetime component of the conformational state of LHCII in the natural thylakoid membrane environment when the non-photochemical quenching (NPQ) was absent. The 2ns component is related to a pre-aggregated LHCII that makes it more sensitive to pH than the trimeric LHCII with the dominating 3.5ns lifetime component. The pre-aggregated LHCII displayed both a faster response to protons and a shift in the pK for quenching to higher values, from 4.2 to 4.9. We concluded that environmental factors like lipids, zeaxanthin and PsbS protein that modulate NPQ in vivo could control the state of LHCII aggregation in the dark that makes it more or less sensitive to the lumen acidification. This article is part of a special issue entitled: photosynthesis research for sustainability: keys to produce clean energy.
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Affiliation(s)
- Katherina Petrou
- Plant Functional Biology & Climate Change Cluster, University of Technology, Sydney, Australia
| | - Erica Belgio
- School of Biological and Chemical Sciences, Queen Mary University of London, UK
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, UK.
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50
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Belgio E, Duffy CDP, Ruban AV. Switching light harvesting complex II into photoprotective state involves the lumen-facing apoprotein loop. Phys Chem Chem Phys 2013; 15:12253-61. [PMID: 23771239 DOI: 10.1039/c3cp51925b] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In higher plants, high light conditions trigger the activation of non-photochemical quenching (NPQ), a process of photoprotective light energy dissipation, via acidification of the chloroplast lumen. Spectral changes occurring in the neoxanthin domain of the major light harvesting antenna complex (LHCII) have previously provided indirect evidence of a protein conformational switch during NPQ. We report here of two recombinant LHCII complexes mutated at the level of lumenal loop with altered quenching capacity with respect to the control. Replacement of the acidic lumenal-facing residue aspartate 111 (D111) with neutral valine (V111) yielded a recombinant complex with increased quenching capacity under low pH, due to a shift of the pK by 1 pH unit. The increase in total quenching was consistent with 40% reduction in the relative chlorophyll fluorescence lifetime and was accompanied by a lower energy emitting state of the mutant, as demonstrated by 77 K fluorescence spectroscopy. On the other hand, replacement of acidic glutamate 94 (E94) with glycine (G94) resulted in reduction of the fluorescence quenching yield attained at low pH. These results show for the first time that a subtle change in the LHCII apoprotein structure at the level of the lumenal loop induced by single aminoacid mutagenesis can affect protein sensitivity to pH leading to the establishment of NPQ. This work opens a potential avenue for manipulation of light harvesting efficiency in the natural antenna pigment-protein complexes that can be used for the creation of hybrid light energy conversion systems in future.
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Affiliation(s)
- Erica Belgio
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, Fogg Building, London E1 4NS, UK
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