1
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Zerah Harush E, Dubi Y. Signature of Quantum Coherence in the Exciton Energy Pathways of the LH2 Photosynthetic Complex. ACS OMEGA 2023; 8:38871-38878. [PMID: 37901547 PMCID: PMC10601065 DOI: 10.1021/acsomega.3c02676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/15/2023] [Indexed: 10/31/2023]
Abstract
Unraveling the energy transfer pathways in photosynthetic complexes is an important step toward understanding their structure-function interplay. Here, we use an open quantum systems approach to investigate energy transfer within the LH2 photosynthetic apparatus and its dependence on environmental conditions. We find that energy transfer pathways strongly depend on the environment-induced dephasing time. A comparison between the computational results and experiments performed on similar systems demonstrates that quantum coherences are present in these systems under physiological conditions and have an important role in shaping the energy transfer pathways. Moreover, our calculations indicate that relatively simple spectroscopy experiments can be used to detect traces of quantum coherence. Finally, our results suggest that quantum coherence may play a role in photosynthesis, but not in enhancing the efficiency as was previously suggested.
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Affiliation(s)
- Elinor Zerah Harush
- Department of Chemistry and
Ilse Katz Center for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Yonatan Dubi
- Department of Chemistry and
Ilse Katz Center for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
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2
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Novoderezhkin VI. Excitation energy equilibration in a trimeric LHCII complex involves unusual pathways. Phys Chem Chem Phys 2023; 25:26360-26369. [PMID: 37750240 DOI: 10.1039/d3cp02836d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
We explore the energy equilibration within the LHCII trimer using various approaches, including the Redfield-Förster method (with different compartmentalization schemes) and the exact hierarchical equation of motion (HEOM). We demonstrate that the inter-monomeric migration in the trimeric LHCII complex is not limited to direct transfers between quasi-equilibrated chlorophylls (Chls) a, but also involves additional pathways with uphill transfers from Chls a to the stromal-side Chls b (connecting the Chls a clusters from different monomeric subunits). Although these uphill transfers are slow they still can increase the total rate of inter-monomeric transfers by a factor of 1.5. The same stromal-side Chls b also promote a depopulation of the Chl a604 long-lived state (blue-shifted and mixed with the lumenal-side Chls b). Due to the connection between the stromal- and lumenal-side Chls b clusters the intra- and inter-monomeric transfers from a604 to the main Chls a become faster by a factor of 1.6 and 1.75, respectively.
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Affiliation(s)
- Vladimir I Novoderezhkin
- A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 119992, Moscow, Russia.
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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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Harris D, Toporik H, Schlau-Cohen GS, Mazor Y. Energetic robustness to large scale structural fluctuations in a photosynthetic supercomplex. Nat Commun 2023; 14:4650. [PMID: 37532717 PMCID: PMC10397321 DOI: 10.1038/s41467-023-40146-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 07/14/2023] [Indexed: 08/04/2023] Open
Abstract
Photosynthetic organisms transport and convert solar energy with near-unity quantum efficiency using large protein supercomplexes held in flexible membranes. The individual proteins position chlorophylls to tight tolerances considered critical for fast and efficient energy transfer. The variability in protein organization within the supercomplexes, and how efficiency is maintained despite variability, had been unresolved. Here, we report on structural heterogeneity in the 2-MDa cyanobacterial PSI-IsiA photosynthetic supercomplex observed using Cryo-EM, revealing large-scale variances in the positions of IsiA relative to PSI. Single-molecule measurements found efficient IsiA-to-PSI energy transfer across all conformations, along with signatures of transiently decoupled IsiA. Structure based calculations showed that rapid IsiA-to-PSI energy transfer is always maintained, and even increases by three-fold in rare conformations via IsiA-specific chls. We postulate that antennae design mitigates structural fluctuations, providing a mechanism for robust energy transfer in the flexible membrane.
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Affiliation(s)
- Dvir Harris
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Hila Toporik
- Biodesign Institute, School of Molecular Sciences, Arizona State University, Tempe, AZ, 85801, USA
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Gabriela S Schlau-Cohen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
| | - Yuval Mazor
- Biodesign Institute, School of Molecular Sciences, Arizona State University, Tempe, AZ, 85801, USA.
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA.
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5
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Nöthling JA, Mancal T, Kruger T. Accuracy of approximate methods for the calculation of absorption-type linear spectra with a complex system-bath coupling. J Chem Phys 2022; 157:095103. [DOI: 10.1063/5.0100977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The accuracy of approximate methods for calculating linear optical spectra depends on many variables. In this study, we fix most of these parameters to typical values found in photosynthetic light-harvesting complexes of plants and determine the accuracy of approximate spectra with respect to exact calculation as a function of the energy gap and interpigment coupling in a pigment dimer. We use a spectral density with the first eight intramolecular modes of chlorophyll a and include inhomogeneous disorder for the calculation of spectra. We compare the accuracy of absorption, linear dichroism, and circular dichroism spectra calculated using the Full Cumulant Expansion (FCE), coherent time-dependent Redfield (ctR), and time-independent Redfield and modified Redfield methods. As a reference we use spectra calculated with the Exact Stochastic Path Integral Evaluation method. We find the FCE method to be the most accurate for the calculation of all spectra. The ctR method performs well for the qualitative calculation of absorption and linear dichroism spectra when pigments are moderately coupled (∼15 cm-1), but ctR spectra may differ significantly from exact spectra when strong interpigment coupling (>100 cm-1) is present. The dependence of the quality of Redfield and modified Redfield spectra on molecular parameters is similar, and these methods almost always perform worse than ctR, especially when the interpigment coupling is strong or the excitonic energy gap is small (for a given coupling). The accuracy of approximate spectra is not affected by resonance with intramolecular modes for typical system-bath coupling and disorder values found in plant light-harvesting complexes.
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Affiliation(s)
| | - Tomas Mancal
- Faculty of Mathematics and Physics, Charles University Faculty of Mathematics and Physics, Czech Republic
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6
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Ko L, Cook RL, Whaley KB. Dynamics of photosynthetic light harvesting systems interacting with N-photon Fock states. J Chem Phys 2022; 156:244108. [DOI: 10.1063/5.0082822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We develop a method to simulate the excitonic dynamics of realistic photosynthetic light harvesting systems, including non-Markovian coupling to phonon degrees of freedom, under excitation by N-photon Fock state pulses. This method combines the input–output and the hierarchical equations of motion formalisms into a double hierarchy of density matrix equations. We show analytically that under weak field excitation relevant to natural photosynthesis conditions, an N-photon Fock state input and a corresponding coherent state input give rise to equal density matrices in the excited manifold. However, an N-photon Fock state input induces no off-diagonal coherence between the ground and excited subspaces, in contrast with the coherences created by a coherent state input. We derive expressions for the probability to absorb a single Fock state photon with or without the influence of phonons. For short pulses (or, equivalently, wide bandwidth pulses), we show that the absorption probability has a universal behavior that depends only upon a system-dependent effective energy spread parameter Δ and an exciton–light coupling constant Γ. This holds for a broad range of chromophore systems and for a variety of pulse shapes. We also analyze the absorption probability in the opposite long pulse (narrow bandwidth) regime. We then derive an expression for the long time emission rate in the presence of phonons and use it to study the difference between collective vs independent emission. Finally, we present a numerical simulation for the LHCII monomer (14-mer) system under single photon excitation that illustrates the use of the double hierarchy equations.
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Affiliation(s)
- Liwen Ko
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Kavli Energy Nanoscience Institute at Berkeley, Berkeley, California 94720, USA
| | - Robert L. Cook
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Kavli Energy Nanoscience Institute at Berkeley, Berkeley, California 94720, USA
| | - K. Birgitta Whaley
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Kavli Energy Nanoscience Institute at Berkeley, Berkeley, California 94720, USA
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7
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Holmes J, Sushma AA, Tsvetkova IB, Schaich WL, Schaller RD, Dragnea B. Ultrafast Collective Excited-State Dynamics of a Virus-Supported Fluorophore Antenna. J Phys Chem Lett 2022; 13:3237-3243. [PMID: 35380843 PMCID: PMC9306353 DOI: 10.1021/acs.jpclett.2c00262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Radiation brightening was recently observed in a multifluorophore-conjugated brome mosaic virus (BMV) particle at room temperature under pulsed excitation. On the basis of its nonlinear dependence on the number of chromophores, the origins of the phenomenon were attributed to a collective relaxation. However, the mechanism remains unknown. We present ultrafast transient absorption and fluorescence spectroscopic studies which shed new light on the collective nature of the relaxation dynamics in such radiation-brightened, multifluorophore particles. Our findings indicate that the emission dynamics is consistent with a superradiance mechanism. The ratio between the rates of competing radiative and nonradiative relaxation pathways depends on the number of chromophores per virus. The findings suggest that small icosahedral virus shells provide a unique biological scaffold for developing nonclassical, deep subwavelength light sources and may open new avenues for the development of photonic probes for medical imaging applications.
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Affiliation(s)
- Joseph Holmes
- Physics Department, Indiana University, Bloomington, Indiana 47405, United States
| | - Arathi Anil Sushma
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Irina B Tsvetkova
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - William L Schaich
- Physics Department, Indiana University, Bloomington, Indiana 47405, United States
| | - Richard D Schaller
- The Center for Nanoscale Materials at Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Bogdan Dragnea
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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8
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Grzyb J, Walczewska-Szewc K, Sławski J, Trojnar M. Quantum dot clusters as self-assembled antennae with phycocyanine and phycobilisomes as energy acceptors. Phys Chem Chem Phys 2021; 23:24505-24517. [PMID: 34700331 DOI: 10.1039/d1cp03347f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, we investigated an experimental and Monte-Carlo computational characterization of self-assembled antennae built using CdTe colloidal quantum dots (QDs). These clusters provide efficient excitation of phycocyanine (PC) or phycobilisomes (PBSs). PBSs are light-harvesting complexes (LHCs) of cyanobacteria, made of several PC units, organized in disks and rods. Each PC contains three separate cofactors. Therefore, we analyzed variations in multi-donor and multi-acceptor systems. The self-assembled QD clusters were formed mostly by electrostatic interactions, possibly due to the introduction of a positive charge on an originally negatively charged nanoparticle surface. Our results suggest that PC may accept energy from multiple nanoparticles localized at a distance significantly longer than the Förster radius. The excitation transfers between particular nanoparticles with possible delocalization. The maximal energy transfer efficiency was obtained for the PC/PBS : QD ratio from 1 to 20 depending on the QD size. This cannot be fully explained using computational simulations; hence, we discussed the hypothesis and explained the observations. Our self-assembled systems may be considered for possible applications in artificial light-harvesting systems because absorption spectra of QDs are different from the absorption characteristics of PC/PBS. In addition, huge clusters of QDs may effectively increase the optical cross-section of so-created nanohybrids.
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Affiliation(s)
- Joanna Grzyb
- Department of Biophysics, Faculty of Biotechnology, University of Wrocław, F. Joliot-Curie 14a str, 50-383 Wrocław, Poland.
| | - Katarzyna Walczewska-Szewc
- Department of Biophysics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziądzka 5 str., 87-100 Toruń, Poland.,Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wileńska 4 str., 87-100 Toruń, Poland
| | - Jakub Sławski
- Department of Biophysics, Faculty of Biotechnology, University of Wrocław, F. Joliot-Curie 14a str, 50-383 Wrocław, Poland.
| | - Martyna Trojnar
- Department of Biophysics, Faculty of Biotechnology, University of Wrocław, F. Joliot-Curie 14a str, 50-383 Wrocław, Poland.
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9
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Malina T, Koehorst R, Bína D, Pšenčík J, van Amerongen H. Superradiance of bacteriochlorophyll c aggregates in chlorosomes of green photosynthetic bacteria. Sci Rep 2021; 11:8354. [PMID: 33863954 PMCID: PMC8052352 DOI: 10.1038/s41598-021-87664-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/01/2021] [Indexed: 01/18/2023] Open
Abstract
Chlorosomes are the main light-harvesting complexes of green photosynthetic bacteria that are adapted to a phototrophic life at low-light conditions. They contain a large number of bacteriochlorophyll c, d, or e molecules organized in self-assembling aggregates. Tight packing of the pigments results in strong excitonic interactions between the monomers, which leads to a redshift of the absorption spectra and excitation delocalization. Due to the large amount of disorder present in chlorosomes, the extent of delocalization is limited and further decreases in time after excitation. In this work we address the question whether the excitonic interactions between the bacteriochlorophyll c molecules are strong enough to maintain some extent of delocalization even after exciton relaxation. That would manifest itself by collective spontaneous emission, so-called superradiance. We show that despite a very low fluorescence quantum yield and short excited state lifetime, both caused by the aggregation, chlorosomes indeed exhibit superradiance. The emission occurs from states delocalized over at least two molecules. In other words, the dipole strength of the emissive states is larger than for a bacteriochlorophyll c monomer. This represents an important functional mechanism increasing the probability of excitation energy transfer that is vital at low-light conditions. Similar behaviour was observed also in one type of artificial aggregates, and this may be beneficial for their potential use in artificial photosynthesis.
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Affiliation(s)
- Tomáš Malina
- Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
| | - Rob Koehorst
- Laboratory of Biophysics, Wageningen University, Wageningen, The Netherlands.,MicroSpectroscopy Research Facility, Wageningen University, Wageningen, The Netherlands
| | - David Bína
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.,Biology Centre, Czech Academy of Science, České Budějovice, Czech Republic
| | - Jakub Pšenčík
- Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic.
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, Wageningen, The Netherlands.,MicroSpectroscopy Research Facility, Wageningen University, Wageningen, The Netherlands
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10
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Sherman J, Gorbunov MY, Schofield O, Falkowski PG. Photosynthetic energy conversion efficiency in the West Antarctic Peninsula. LIMNOLOGY AND OCEANOGRAPHY 2020; 65:2912-2925. [PMID: 33380749 PMCID: PMC7754432 DOI: 10.1002/lno.11562] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 04/18/2020] [Accepted: 06/23/2020] [Indexed: 06/12/2023]
Abstract
The West Antarctic Peninsula (WAP) is a highly productive polar ecosystem where phytoplankton dynamics are regulated by intense bottom-up control from light and iron availability. Rapid climate change along the WAP is driving shifts in the mixed layer depth and iron availability. Elucidating the relative role of each of these controls and their interactions is crucial for understanding of how primary productivity will change in coming decades. Using a combination of ultra-high-resolution variable chlorophyll fluorescence together with fluorescence lifetime analyses on the 2017 Palmer Long Term Ecological Research cruise, we mapped the temporal and spatial variability in phytoplankton photophysiology across the WAP. Highest photosynthetic energy conversion efficiencies and lowest fluorescence quantum yields were observed in iron replete coastal regions. Photosynthetic energy conversion efficiencies decreased by ~ 60% with a proportional increase in quantum yields of thermal dissipation and fluorescence on the outer continental shelf and slope. The combined analysis of variable fluorescence and lifetimes revealed that, in addition to the decrease in the fraction of inactive reaction centers, up to 20% of light harvesting chlorophyll-protein antenna complexes were energetically uncoupled from photosystem II reaction centers in iron-limited phytoplankton. These biophysical signatures strongly suggest severe iron limitation of photosynthesis in the surface waters along the continental slope of the WAP.
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Affiliation(s)
- Jonathan Sherman
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, RutgersThe State University of New JerseyNew BrunswickNew JerseyUSA
| | - Maxim Y. Gorbunov
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, RutgersThe State University of New JerseyNew BrunswickNew JerseyUSA
| | - Oscar Schofield
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, RutgersThe State University of New JerseyNew BrunswickNew JerseyUSA
- Center for Ocean Observing Leadership, Department of Marine and Coastal SciencesRutgers, The State University of New JerseyNew BrunswickNew JerseyUSA
| | - Paul G. Falkowski
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, RutgersThe State University of New JerseyNew BrunswickNew JerseyUSA
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11
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Kondo T, Mutoh R, Tabe H, Kurisu G, Oh-Oka H, Fujiyoshi S, Matsushita M. Cryogenic Single-Molecule Spectroscopy of the Primary Electron Acceptor in the Photosynthetic Reaction Center. J Phys Chem Lett 2020; 11:3980-3986. [PMID: 32352789 DOI: 10.1021/acs.jpclett.0c00891] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The photosynthetic reaction center (RC) converts light energy into electrochemical energy. The RC of heliobacteria (hRC) is a primitive homodimeric RC containing 58 bacteriochlorophylls and 2 chlorophyll as. The chlorophyll serves as the primary electron acceptor (Chl a-A0) responsible for light harvesting and charge separation. The single-molecule spectroscopy of Chl a-A0 can be used to investigate heterogeneities of the RC photochemical function, though the low fluorescence quantum yield (0.1%) makes it difficult. Here, we show the fluorescence excitation spectroscopy of individual Chl a-A0s in single hRCs at 6 K. The fluorescence quantum yield and absorption cross section of Chl a-A0 increase 2- and 4-fold, respectively, compared to those at room temperature. The two Chl a-A0s in single hRCs are identified as two distinct peaks in the fluorescence excitation spectrum, exhibiting different excitation polarization dependences. The spectral changes caused by photobleaching indicate the energy transfer across subunits in the hRC.
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Affiliation(s)
- Toru Kondo
- Department of Physics, Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan
| | - Risa Mutoh
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hiroaki Tabe
- Department of Physics, Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan
| | - Genji Kurisu
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hirozo Oh-Oka
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Satoru Fujiyoshi
- Department of Physics, Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan
| | - Michio Matsushita
- Department of Physics, Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan
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12
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van Amerongen H, Chmeliov J. Instantaneous switching between different modes of non-photochemical quenching in plants. Consequences for increasing biomass production. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148119. [DOI: 10.1016/j.bbabio.2019.148119] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 10/29/2019] [Accepted: 11/08/2019] [Indexed: 11/25/2022]
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13
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Tietz S, Leuenberger M, Höhner R, Olson AH, Fleming GR, Kirchhoff H. A proteoliposome-based system reveals how lipids control photosynthetic light harvesting. J Biol Chem 2020; 295:1857-1866. [PMID: 31929108 DOI: 10.1074/jbc.ra119.011707] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/09/2020] [Indexed: 11/06/2022] Open
Abstract
Integral membrane proteins are exposed to a complex and dynamic lipid environment modulated by nonbilayer lipids that can influence protein functions by lipid-protein interactions. The nonbilayer lipid monogalactosyldiacylglycerol (MGDG) is the most abundant lipid in plant photosynthetic thylakoid membranes, but its impact on the functionality of energy-converting membrane protein complexes is unknown. Here, we optimized a detergent-based reconstitution protocol to develop a proteoliposome technique that incorporates the major light-harvesting complex II (LHCII) into compositionally well-defined large unilamellar lipid bilayer vesicles to study the impact of MGDG on light harvesting by LHCII. Using steady-state fluorescence spectroscopy, CD spectroscopy, and time-correlated single-photon counting, we found that both chlorophyll fluorescence quantum yields and fluorescence lifetimes clearly indicate that the presence of MGDG in lipid bilayers switches LHCII from a light-harvesting to a more energy-quenching mode that dissipates harvested light into heat. It is hypothesized that in the in vitro system developed here, MGDG controls light harvesting of LHCII by modulating the hydrostatic lateral membrane pressure profile in the lipid bilayer sensed by LHCII-bound peripheral pigments.
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Affiliation(s)
- Stefanie Tietz
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, 99164-6340
| | - Michelle Leuenberger
- Department of Chemistry, University of California, Berkeley, California 94720; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Ricarda Höhner
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, 99164-6340
| | - Alice H Olson
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, 99164-6340
| | - Graham R Fleming
- Department of Chemistry, University of California, Berkeley, California 94720; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Helmut Kirchhoff
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, 99164-6340.
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14
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Bourne Worster S, Stross C, Vaughan FMWC, Linden N, Manby FR. Structure and Efficiency in Bacterial Photosynthetic Light Harvesting. J Phys Chem Lett 2019; 10:7383-7390. [PMID: 31714789 DOI: 10.1021/acs.jpclett.9b02625] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Photosynthetic organisms use networks of chromophores to absorb and deliver solar energy to reaction centers. We present a detailed model of the light-harvesting complexes in purple bacteria, including explicit interaction with sunlight, radiative and nonradiative energy loss, and dephasing and thermalizing effects of coupling to a vibrational bath. We capture the effect of slow vibrations by introducing time-dependent disorder. Our model describes the experimentally observed high efficiency of light harvesting, despite the absence of long-range quantum coherence. The one-exciton part of the quantum state fluctuates continuously but remains highly mixed at all times. These results suggest a relatively minor role for structure in determining efficiency. We build hypothetical models with randomly arranged chromophores but still observe high efficiency when nearest-neighbor distances are comparable to those in nature. This helps explain the high transport efficiency in organisms with widely differing antenna structures and suggests new design criteria for artificial light-harvesting devices.
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Affiliation(s)
- Susannah Bourne Worster
- Centre for Computational Chemistry, School of Chemistry , University of Bristol , Bristol BS8 1TS , U.K
| | - Clement Stross
- Centre for Computational Chemistry, School of Chemistry , University of Bristol , Bristol BS8 1TS , U.K
- School of Mathematics , University of Bristol , Bristol BS8 1UG , U.K
| | - Felix M W C Vaughan
- Centre for Computational Chemistry, School of Chemistry , University of Bristol , Bristol BS8 1TS , U.K
- School of Mathematics , University of Bristol , Bristol BS8 1UG , U.K
- Bristol Centre for Complexity Sciences , University of Bristol , Bristol BS2 8BB , U.K
| | - Noah Linden
- School of Mathematics , University of Bristol , Bristol BS8 1UG , U.K
| | - Frederick R Manby
- Centre for Computational Chemistry, School of Chemistry , University of Bristol , Bristol BS8 1TS , U.K
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15
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Bos P, Oosterwijk A, Koehorst R, Bader A, Philippi J, van Amerongen H, Wientjes E. Digitonin-sensitive LHCII enlarges the antenna of Photosystem I in stroma lamellae of Arabidopsis thaliana after far-red and blue-light treatment. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:651-658. [PMID: 31299182 DOI: 10.1016/j.bbabio.2019.07.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 06/14/2019] [Accepted: 07/07/2019] [Indexed: 11/16/2022]
Abstract
Light drives photosynthesis. In plants it is absorbed by light-harvesting antenna complexes associated with Photosystem I (PSI) and photosystem II (PSII). As PSI and PSII work in series, it is important that the excitation pressure on the two photosystems is balanced. When plants are exposed to illumination that overexcites PSII, a special pool of the major light-harvesting complex LHCII is phosphorylated and moves from PSII to PSI (state 2). If instead PSI is over-excited the LHCII complex is dephosphorylated and moves back to PSII (state 1). Recent findings have suggested that LHCII might also transfer energy to PSI in state 1. In this work we used a combination of biochemistry and (time-resolved) fluorescence spectroscopy to investigate the PSI antenna size in state 1 and state 2 for Arabidopsis thaliana. Our data shows that 0.7 ± 0.1 unphosphorylated LHCII trimers per PSI are present in the stroma lamellae of state-1 plants. Upon transition to state 2 the antenna size of PSI in the stroma membrane increases with phosphorylated LHCIIs to a total of 1.2 ± 0.1 LHCII trimers per PSI. Both phosphorylated and unphosphorylated LHCII function as highly efficient PSI antenna.
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Affiliation(s)
- Peter Bos
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Anniek Oosterwijk
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Rob Koehorst
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Arjen Bader
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - John Philippi
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands; MicroSpectroscopy Research Facility, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, the Netherlands.
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16
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van den Berg TE, van Oort B, Croce R. Light-harvesting complexes of Botryococcus braunii. PHOTOSYNTHESIS RESEARCH 2018; 135:191-201. [PMID: 28551868 PMCID: PMC5783996 DOI: 10.1007/s11120-017-0405-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/20/2017] [Indexed: 05/03/2023]
Abstract
The colonial green alga Botryococcus braunii (BB) is a potential source of biofuel due to its natural high hydrocarbon content. Unfortunately, its slow growth limits its biotechnological potential. Understanding its photosynthetic machinery could help to identify possible growth limitations. Here, we present the first study on BB light-harvesting complexes (LHCs). We purified two LHC fractions containing the complexes in monomeric and trimeric form. Both fractions contained at least two proteins with molecular weight (MW) around 25 kDa. The chlorophyll composition is similar to that of the LHCII of plants; in contrast, the main xanthophyll is loroxanthin, which substitutes lutein in most binding sites. Circular dichroism and 77 K absorption spectra lack typical differences between monomeric and trimeric complexes, suggesting that intermonomer interactions do not play a role in BB LHCs. This is in agreement with the low stability of the BB LHCII trimers as compared to the complexes of plants, which could be related to loroxanthin binding in the central (L1 and L2) binding sites. The properties of BB LHCII are similar to those of plant LHCII, indicating a similar pigment organization. Differences are a higher content of red chlorophyll a, similar to plant Lhcb3. These differences and the different Xan composition had no effect on excitation energy transfer or fluorescence lifetimes, which were similar to plant LHCII.
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Affiliation(s)
- Tomas E van den Berg
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Bart van Oort
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Roberta Croce
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, 1081 HV, Amsterdam, The Netherlands.
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17
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Wientjes E, Philippi J, Borst JW, van Amerongen H. Imaging the Photosystem I/Photosystem II chlorophyll ratio inside the leaf. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:259-265. [DOI: 10.1016/j.bbabio.2017.01.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/10/2017] [Accepted: 01/13/2017] [Indexed: 02/03/2023]
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18
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Kondo T, Chen WJ, Schlau-Cohen GS. Single-Molecule Fluorescence Spectroscopy of Photosynthetic Systems. Chem Rev 2017; 117:860-898. [DOI: 10.1021/acs.chemrev.6b00195] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Toru Kondo
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge Massachusetts 02139, United States
| | - Wei Jia Chen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge Massachusetts 02139, United States
| | - Gabriela S. Schlau-Cohen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge Massachusetts 02139, United States
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19
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Akhtar P, Zhang C, Do TN, Garab G, Lambrev PH, Tan HS. Two-Dimensional Spectroscopy of Chlorophyll a Excited-State Equilibration in Light-Harvesting Complex II. J Phys Chem Lett 2017; 8:257-263. [PMID: 27982601 DOI: 10.1021/acs.jpclett.6b02615] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Excited-state relaxation dynamics and energy-transfer processes in the chlorophyll a (Chl a) manifold of the light-harvesting complex II (LHCII) were examined at physiological temperature using femtosecond two-dimensional electronic spectroscopy (2DES). The experiments were done under conditions free from singlet-singlet annihilation and anisotropic decay. Energy transfer between the different domains of the Chl a manifold was found to proceed on time scales from hundreds of femtoseconds to five picoseconds, before reaching equilibration. No component slower than 10 ps was observed in the spectral equilibration dynamics. We clearly observe the bidirectional (uphill and downhill) energy transfer of the equilibration process between excited states. This bidirectional energy flow, although implicit in the modeling and simulation of the EET processes, has not been observed in any prior transient absorption studies. Furthermore, we identified the spectral forms associated with the different energy transfer lifetimes in the equilibration process.
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Affiliation(s)
- Parveen Akhtar
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
- Biological Research Centre, Hungarian Academy of Sciences , Temesvári körút 62, Szeged 6726, Hungary
| | - Cheng Zhang
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
| | - Thanh Nhut Do
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
| | - Győző Garab
- Biological Research Centre, Hungarian Academy of Sciences , Temesvári körút 62, Szeged 6726, Hungary
| | - Petar H Lambrev
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
- Biological Research Centre, Hungarian Academy of Sciences , Temesvári körút 62, Szeged 6726, Hungary
| | - Howe-Siang Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , 21 Nanyang Link, Singapore 637371
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20
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Snellenburg JJ, Wlodarczyk LM, Dekker JP, van Grondelle R, van Stokkum IH. A model for the 77 K excited state dynamics in Chlamydomonas reinhardtii in state 1 and state 2. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:64-72. [DOI: 10.1016/j.bbabio.2016.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/06/2016] [Accepted: 10/07/2016] [Indexed: 01/28/2023]
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21
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Alboresi A, Le Quiniou C, Yadav SKN, Scholz M, Meneghesso A, Gerotto C, Simionato D, Hippler M, Boekema EJ, Croce R, Morosinotto T. Conservation of core complex subunits shaped the structure and function of photosystem I in the secondary endosymbiont alga Nannochloropsis gaditana. THE NEW PHYTOLOGIST 2017; 213:714-726. [PMID: 27620972 PMCID: PMC5216901 DOI: 10.1111/nph.14156] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 07/13/2016] [Indexed: 05/03/2023]
Abstract
Photosystem I (PSI) is a pigment protein complex catalyzing the light-driven electron transport from plastocyanin to ferredoxin in oxygenic photosynthetic organisms. Several PSI subunits are highly conserved in cyanobacteria, algae and plants, whereas others are distributed differentially in the various organisms. Here we characterized the structural and functional properties of PSI purified from the heterokont alga Nannochloropsis gaditana, showing that it is organized as a supercomplex including a core complex and an outer antenna, as in plants and other eukaryotic algae. Differently from all known organisms, the N. gaditana PSI supercomplex contains five peripheral antenna proteins, identified by proteome analysis as type-R light-harvesting complexes (LHCr4-8). Two antenna subunits are bound in a conserved position, as in PSI in plants, whereas three additional antennae are associated with the core on the other side. This peculiar antenna association correlates with the presence of PsaF/J and the absence of PsaH, G and K in the N. gaditana genome and proteome. Excitation energy transfer in the supercomplex is highly efficient, leading to a very high trapping efficiency as observed in all other PSI eukaryotes, showing that although the supramolecular organization of PSI changed during evolution, fundamental functional properties such as trapping efficiency were maintained.
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Affiliation(s)
- Alessandro Alboresi
- Dipartimento di BiologiaUniversità di PadovaVia U. Bassi 58/B35121PadovaItaly
| | - Clotilde Le Quiniou
- Department of Physics and Astronomy and Institute for Lasers, Life and BiophotonicsFaculty of SciencesVU University AmsterdamDe Boelelaan 10811081 HVAmsterdamthe Netherlands
| | - Sathish K. N. Yadav
- Electron Microscopy GroupGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenNijenborgh 79747 AGGroningenthe Netherlands
| | - Martin Scholz
- Institute of Plant Biology and BiotechnologyUniversity of MünsterMünster48143Germany
| | - Andrea Meneghesso
- Dipartimento di BiologiaUniversità di PadovaVia U. Bassi 58/B35121PadovaItaly
| | - Caterina Gerotto
- Dipartimento di BiologiaUniversità di PadovaVia U. Bassi 58/B35121PadovaItaly
| | - Diana Simionato
- Dipartimento di BiologiaUniversità di PadovaVia U. Bassi 58/B35121PadovaItaly
| | - Michael Hippler
- Institute of Plant Biology and BiotechnologyUniversity of MünsterMünster48143Germany
| | - Egbert J. Boekema
- Electron Microscopy GroupGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenNijenborgh 79747 AGGroningenthe Netherlands
| | - Roberta Croce
- Department of Physics and Astronomy and Institute for Lasers, Life and BiophotonicsFaculty of SciencesVU University AmsterdamDe Boelelaan 10811081 HVAmsterdamthe Netherlands
| | - Tomas Morosinotto
- Dipartimento di BiologiaUniversità di PadovaVia U. Bassi 58/B35121PadovaItaly
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22
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Mirkovic T, Ostroumov EE, Anna JM, van Grondelle R, Govindjee, Scholes GD. Light Absorption and Energy Transfer in the Antenna Complexes of Photosynthetic Organisms. Chem Rev 2016; 117:249-293. [PMID: 27428615 DOI: 10.1021/acs.chemrev.6b00002] [Citation(s) in RCA: 610] [Impact Index Per Article: 76.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The process of photosynthesis is initiated by the capture of sunlight by a network of light-absorbing molecules (chromophores), which are also responsible for the subsequent funneling of the excitation energy to the reaction centers. Through evolution, genetic drift, and speciation, photosynthetic organisms have discovered many solutions for light harvesting. In this review, we describe the underlying photophysical principles by which this energy is absorbed, as well as the mechanisms of electronic excitation energy transfer (EET). First, optical properties of the individual pigment chromophores present in light-harvesting antenna complexes are introduced, and then we examine the collective behavior of pigment-pigment and pigment-protein interactions. The description of energy transfer, in particular multichromophoric antenna structures, is shown to vary depending on the spatial and energetic landscape, which dictates the relative coupling strength between constituent pigment molecules. In the latter half of the article, we focus on the light-harvesting complexes of purple bacteria as a model to illustrate the present understanding of the synergetic effects leading to EET optimization of light-harvesting antenna systems while exploring the structure and function of the integral chromophores. We end this review with a brief overview of the energy-transfer dynamics and pathways in the light-harvesting antennas of various photosynthetic organisms.
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Affiliation(s)
- Tihana Mirkovic
- Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Evgeny E Ostroumov
- Department of Chemistry, Princeton University , Washington Road, Princeton, New Jersey 08544, United States
| | - Jessica M Anna
- Department of Chemistry, University of Pennsylvania , 231 S. 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Rienk van Grondelle
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam , De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Govindjee
- Department of Biochemistry, Center of Biophysics & Quantitative Biology, and Department of Plant Biology, University of Illinois at Urbana-Champaign , 265 Morrill Hall, 505 South Goodwin Avenue, Urbana, Illinois 61801, United States
| | - Gregory D Scholes
- Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.,Department of Chemistry, Princeton University , Washington Road, Princeton, New Jersey 08544, United States
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23
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Ramanan C, Gruber JM, Malý P, Negretti M, Novoderezhkin V, Krüger TPJ, Mančal T, Croce R, van Grondelle R. The role of exciton delocalization in the major photosynthetic light-harvesting antenna of plants. Biophys J 2016; 108:1047-56. [PMID: 25762317 DOI: 10.1016/j.bpj.2015.01.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 01/05/2015] [Accepted: 01/21/2015] [Indexed: 11/18/2022] Open
Abstract
In the major peripheral plant light-harvesting complex LHCII, excitation energy is transferred between chlorophylls along an energetic cascade before it is transmitted further into the photosynthetic assembly to be converted into chemical energy. The efficiency of these energy transfer processes involves a complicated interplay of pigment-protein structural reorganization and protein dynamic disorder, and the system must stay robust within the fluctuating protein environment. The final, lowest energy site has been proposed to exist within a trimeric excitonically coupled chlorophyll (Chl) cluster, comprising Chls a610-a611-a612. We studied an LHCII monomer with a site-specific mutation resulting in the loss of Chls a611and a612, and find that this mutant exhibits two predominant overlapping fluorescence bands. From a combination of bulk measurements, single-molecule fluorescence characterization, and modeling, we propose the two fluorescence bands originate from differing conditions of exciton delocalization and localization realized in the mutant. Disruption of the excitonically coupled terminal emitter Chl trimer results in an increased sensitivity of the excited state energy landscape to the disorder induced by the protein conformations. Consequently, the mutant demonstrates a loss of energy transfer efficiency. On the contrary, in the wild-type complex, the strong resonance coupling and correspondingly high degree of excitation delocalization within the Chls a610-a611-a612 cluster dampens the influence of the environment and ensures optimal communication with neighboring pigments. These results indicate that the terminal emitter trimer is thus an essential design principle for maintaining the efficient light-harvesting function of LHCII in the presence of protein disorder.
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Affiliation(s)
- Charusheela Ramanan
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, VU University Amsterdam, Amsterdam, The Netherlands.
| | - J Michael Gruber
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, VU University Amsterdam, Amsterdam, The Netherlands
| | - Pavel Malý
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, VU University Amsterdam, Amsterdam, The Netherlands; Faculty of Mathematics and Physics, Charles University in Prague, Prague, Czech Republic
| | - Marco Negretti
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, VU University Amsterdam, Amsterdam, The Netherlands
| | - Vladimir Novoderezhkin
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - Tjaart P J Krüger
- Department of Physics, Faculty of Natural and Agricultural Sciences, University of Pretoria, Hatfield, South Africa
| | - Tomáš Mančal
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, VU University Amsterdam, Amsterdam, The Netherlands; Faculty of Mathematics and Physics, Charles University in Prague, Prague, Czech Republic
| | - Roberta Croce
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, VU University Amsterdam, Amsterdam, The Netherlands
| | - Rienk van Grondelle
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, VU University Amsterdam, Amsterdam, The Netherlands.
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24
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Jornet-Somoza J, Alberdi-Rodriguez J, Milne BF, Andrade X, Marques MAL, Nogueira F, Oliveira MJT, Stewart JJP, Rubio A. Insights into colour-tuning of chlorophyll optical response in green plants. Phys Chem Chem Phys 2015; 17:26599-606. [PMID: 26250099 PMCID: PMC4598288 DOI: 10.1039/c5cp03392f] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
First-principles calculations within the framework of real-space time-dependent density functional theory have been performed for the complete chlorophyll (Chl) network of the light-harvesting complex from green plants, LHC-II. A local-dipole analysis method developed for this work has made possible the studies of the optical response of individual Chl molecules subjected to the influence of the remainder of the chromophore network. The spectra calculated using our real-space TDDFT method agree with previous suggestions that weak interaction with the protein microenvironment should produce only minor changes in the absorption spectrum of Chl chromophores in LHC-II. In addition, relative shifting of Chl absorption energies leads the stromal and lumenal sides of LHC-II to absorb in slightly different parts of the visible spectrum providing greater coverage of the available light frequencies. The site-specific alterations in Chl excitation energies support the existence of intrinsic energy transfer pathways within the LHC-II complex.
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25
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Tian L, Dinc E, Croce R. LHCII Populations in Different Quenching States Are Present in the Thylakoid Membranes in a Ratio that Depends on the Light Conditions. J Phys Chem Lett 2015; 6:2339-44. [PMID: 26266614 DOI: 10.1021/acs.jpclett.5b00944] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
LHCII is the major antenna complex of plants and algae, where it is involved in light harvesting and photoprotection. Its properties have been extensively studied in vitro, after isolation of the pigment-protein complex from the membranes, but are these properties representative for LHCII in the thylakoid membrane? In this work, we have studied LHCII in the cells of the green alga C. reinhardtii acclimated to different light conditions in the absence of the other components of the photosynthetic apparatus. We show that LHCII exists in the membranes in different fluorescence quenching states, all having a shorter excited-state lifetime than isolated LHCII in detergent. The ratio between these populations depends on the light conditions, indicating that the light is able to regulate the properties of the complexes in the membrane.
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Affiliation(s)
- Lijin Tian
- Department of Physics and Astronomy, Faculty of Sciences and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Emine Dinc
- Department of Physics and Astronomy, Faculty of Sciences and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Roberta Croce
- Department of Physics and Astronomy, Faculty of Sciences and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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26
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Mandal P, Manna JS, Das D, Mitra MK. Excitonic dynamics of Chlorophyll-a molecules in chitosan hydrogel scaffold. Photochem Photobiol Sci 2015; 14:786-91. [DOI: 10.1039/c4pp00305e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Non-coherent energy hopping (hopping rate 4.28 ns−1) through excitonically coupled 23° aligned Chl-a molecules within chitosan hydrogel matrix, for an artificial light harvesting system.
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Affiliation(s)
- Pubali Mandal
- School of Materials Science & Nanotechnology
- Jadavpur University
- Kolkata 700032
- India
| | - Jhimli Sarkar Manna
- School of Materials Science & Nanotechnology
- Jadavpur University
- Kolkata 700032
- India
| | - Debmallya Das
- Metallurgy & Material Engineering Department
- Jadavpur University
- Kolkata 700032
- India
| | - Manoj Kumar Mitra
- Metallurgy & Material Engineering Department
- Jadavpur University
- Kolkata 700032
- India
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27
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Yong CK, Parkinson P, Kondratuk DV, Chen WH, Stannard A, Summerfield A, Sprafke JK, O'Sullivan MC, Beton PH, Anderson HL, Herz LM. Ultrafast delocalization of excitation in synthetic light-harvesting nanorings. Chem Sci 2015; 6:181-189. [PMID: 28553466 PMCID: PMC5424671 DOI: 10.1039/c4sc02424a] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 09/16/2014] [Indexed: 11/21/2022] Open
Abstract
Rings of chlorophyll molecules harvest sunlight remarkably efficiently during photosynthesis in purple bacteria. The key to their efficiency lies in their highly delocalized excited states that allow for ultrafast energy migration. Here we show that a family of synthetic nanorings mimic the ultrafast energy transfer and delocalization observed in nature. π-Conjugated nanorings with diameters of up to 10 nm, consisting of up to 24 porphyrin units, are found to exhibit excitation delocalization within the first 200 fs of light absorption. Transitions from the first singlet excited state of the circular nanorings are dipole-forbidden as a result of symmetry constraints, but these selection rules can be lifted through static and dynamic distortions of the rings. The increase in the radiative emission rate in the larger nanorings correlates with an increase in static disorder expected from Monte Carlo simulations. For highly symmetric rings, the radiative rate is found to increase with increasing temperature. Although this type of thermally activated superradiance has been theoretically predicted in circular chromophore arrays, it has not previously been observed in any natural or synthetic systems. As expected, the activation energy for emission increases when a nanoring is fixed in a circular conformation by coordination to a radial template. These nanorings offer extended chromophores with high excitation delocalization that is remarkably stable against thermally induced disorder. Such findings open new opportunities for exploring coherence effects in nanometer molecular rings and for implementing these biomimetic light-harvesters in man-made devices.
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Affiliation(s)
- Chaw-Keong Yong
- University of Oxford , Department of Physics , Clarendon Laboratory , Parks Road , Oxford , OX1 3PU , UK .
| | - Patrick Parkinson
- University of Oxford , Department of Physics , Clarendon Laboratory , Parks Road , Oxford , OX1 3PU , UK .
| | - Dmitry V Kondratuk
- University of Oxford , Department of Chemistry , Chemistry Research Laboratory , Oxford , OX1 3TA , UK .
| | - Wei-Hsin Chen
- University of Oxford , Department of Physics , Clarendon Laboratory , Parks Road , Oxford , OX1 3PU , UK .
| | - Andrew Stannard
- School of Physics & Astronomy , University of Nottingham , Nottingham , NG7 2RD , UK
| | - Alex Summerfield
- School of Physics & Astronomy , University of Nottingham , Nottingham , NG7 2RD , UK
| | - Johannes K Sprafke
- University of Oxford , Department of Chemistry , Chemistry Research Laboratory , Oxford , OX1 3TA , UK .
| | - Melanie C O'Sullivan
- University of Oxford , Department of Chemistry , Chemistry Research Laboratory , Oxford , OX1 3TA , UK .
| | - Peter H Beton
- School of Physics & Astronomy , University of Nottingham , Nottingham , NG7 2RD , UK
| | - Harry L Anderson
- University of Oxford , Department of Chemistry , Chemistry Research Laboratory , Oxford , OX1 3TA , UK .
| | - Laura M Herz
- University of Oxford , Department of Physics , Clarendon Laboratory , Parks Road , Oxford , OX1 3PU , UK .
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28
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Magdaong NM, Enriquez MM, LaFountain AM, Rafka L, Frank HA. Effect of protein aggregation on the spectroscopic properties and excited state kinetics of the LHCII pigment–protein complex from green plants. PHOTOSYNTHESIS RESEARCH 2013; 118:259-76. [PMID: 24077891 DOI: 10.1007/s11120-013-9924-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 09/09/2013] [Indexed: 05/15/2023]
Abstract
Steady-state and time-resolved absorption and fluorescence spectroscopic experiments have been carried out at room and cryogenic temperatures on aggregated and unaggregated monomeric and trimeric LHCII complexes isolated from spinach chloroplasts. Protein aggregation has been hypothesized to be one of the mechanistic factors controlling the dissipation of excess photo-excited state energy of chlorophyll during the process known as nonphotochemical quenching. The data obtained from the present experiments reveal the role of protein aggregation on the spectroscopic properties and dynamics of energy transfer and excited state deactivation of the protein-bound chlorophyll and carotenoid pigments.
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Single-molecule spectroscopy reveals photosynthetic LH2 complexes switch between emissive states. Proc Natl Acad Sci U S A 2013; 110:10899-903. [PMID: 23776245 DOI: 10.1073/pnas.1310222110] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Photosynthetic organisms flourish under low light intensities by converting photoenergy to chemical energy with near unity quantum efficiency and under high light intensities by safely dissipating excess photoenergy and deleterious photoproducts. The molecular mechanisms balancing these two functions remain incompletely described. One critical barrier to characterizing the mechanisms responsible for these processes is that they occur within proteins whose excited-state properties vary drastically among individual proteins and even within a single protein over time. In ensemble measurements, these excited-state properties appear only as the average value. To overcome this averaging, we investigate the purple bacterial antenna protein light harvesting complex 2 (LH2) from Rhodopseudomonas acidophila at the single-protein level. We use a room-temperature, single-molecule technique, the anti-Brownian electrokinetic trap, to study LH2 in a solution-phase (nonperturbative) environment. By performing simultaneous measurements of fluorescence intensity, lifetime, and spectra of single LH2 complexes, we identify three distinct states and observe transitions occurring among them on a timescale of seconds. Our results reveal that LH2 complexes undergo photoactivated switching to a quenched state, likely by a conformational change, and thermally revert to the ground state. This is a previously unobserved, reversible quenching pathway, and is one mechanism through which photosynthetic organisms can adapt to changes in light intensities.
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Bennett DIG, Amarnath K, Fleming GR. A structure-based model of energy transfer reveals the principles of light harvesting in photosystem II supercomplexes. J Am Chem Soc 2013; 135:9164-73. [PMID: 23679235 DOI: 10.1021/ja403685a] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Photosystem II (PSII) initiates photosynthesis in plants through the absorption of light and subsequent conversion of excitation energy to chemical energy via charge separation. The pigment binding proteins associated with PSII assemble in the grana membrane into PSII supercomplexes and surrounding light harvesting complex II trimers. To understand the high efficiency of light harvesting in PSII requires quantitative insight into energy transfer and charge separation in PSII supercomplexes. We have constructed the first structure-based model of energy transfer in PSII supercomplexes. This model shows that the kinetics of light harvesting cannot be simplified to a single rate limiting step. Instead, substantial contributions arise from both excitation diffusion through the antenna pigments and transfer from the antenna to the reaction center (RC), where charge separation occurs. Because of the lack of a rate-limiting step, fitting kinetic models to fluorescence lifetime data cannot be used to derive mechanistic insight on light harvesting in PSII. This model will clarify the interpretation of chlorophyll fluorescence data from PSII supercomplexes, grana membranes, and leaves.
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Affiliation(s)
- Doran I G Bennett
- Department of Chemistry, University of California, Berkeley, California 94720, USA
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31
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Wilk L, Grunwald M, Liao PN, Walla PJ, Kühlbrandt W. Direct interaction of the major light-harvesting complex II and PsbS in nonphotochemical quenching. Proc Natl Acad Sci U S A 2013; 110:5452-6. [PMID: 23509270 PMCID: PMC3619350 DOI: 10.1073/pnas.1205561110] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The photosystem II (PSII) subunit S (PsbS) plays a key role in nonphotochemical quenching, a photoprotective mechanism for dissipation of excess excitation energy in plants. The precise function of PsbS in nonphotochemical quenching is unknown. By reconstituting PsbS together with the major light-harvesting complex of PSII (LHC-II) and the xanthophyll zeaxanthin (Zea) into proteoliposomes, we have tested the individual contributions of PSII complexes and Zea to chlorophyll (Chl) fluorescence quenching in a membrane environment. We demonstrate that PsbS is stable in the absence of pigments in vitro. Significant Chl fluorescence quenching of reconstituted LHC-II was observed in the presence of PsbS and Zea, although neither Zea nor PsbS alone was sufficient to induce the same quenching. Coreconstitution with PsbS resulted in the formation of LHC-II/PsbS heterodimers, indicating their direct interaction in the lipid bilayer. Two-photon excitation measurements on liposomes containing LHC-II, PsbS, and Zea showed an increase of electronic interactions between carotenoid S1 and Chl states, Φ(Coupling)(CarS1-Chl), that correlated directly with Chl fluorescence quenching. These findings are in agreement with a carotenoid-dependent Chl fluorescence quenching by direct interactions of LHCs of PSII with PsbS monomers.
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Affiliation(s)
- Laura Wilk
- Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt, Germany
| | - Matthias Grunwald
- Research Group Biomolecular Spectroscopy and Single-Molecule Detection, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany; and
| | - Pen-Nan Liao
- Department of Biophysical Chemistry, Institute for Physical and Theoretical Chemistry, University of Braunschweig, 38106 Braunschweig, Germany
| | - Peter Jomo Walla
- Research Group Biomolecular Spectroscopy and Single-Molecule Detection, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany; and
- Department of Biophysical Chemistry, Institute for Physical and Theoretical Chemistry, University of Braunschweig, 38106 Braunschweig, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt, Germany
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LHCII is an antenna of both photosystems after long-term acclimation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:420-6. [DOI: 10.1016/j.bbabio.2012.12.009] [Citation(s) in RCA: 173] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Revised: 11/25/2012] [Accepted: 12/27/2012] [Indexed: 11/17/2022]
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33
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Busheva M, Tzonova I, Stoitchkova K, Andreeva A. Heat-induced reorganization of the structure of photosystem II membranes: Role of oxygen evolving complex. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2012; 117:214-21. [DOI: 10.1016/j.jphotobiol.2012.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 10/04/2012] [Accepted: 10/12/2012] [Indexed: 10/27/2022]
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Abasto DF, Mohseni M, Lloyd S, Zanardi P. Exciton diffusion length in complex quantum systems: the effects of disorder and environmental fluctuations on symmetry-enhanced supertransfer. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2012; 370:3750-70. [PMID: 22753824 DOI: 10.1098/rsta.2011.0213] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Symmetric couplings among aggregates of n chromophores increase the transfer rate of excitons by a factor n(2), a quantum-mechanical phenomenon called 'supertransfer'. In this work, we demonstrate how supertransfer effects induced by geometrical symmetries can enhance the exciton diffusion length by a factor n along cylindrically symmetric structures, consisting of arrays of rings of chromophores, and along spiral arrays. We analyse both closed-system dynamics and open quantum dynamics, modelled by combining a random bosonic bath with static disorder. In the closed-system case, we use the symmetries of the system within a short-time approximation to obtain a closed analytical expression for the diffusion length that explicitly reveals the supertransfer contribution. When subject to disorder, we show that supertransfer can enhance excitonic diffusion lengths for small disorders and characterize the crossover from coherent to incoherent motion. Owing to the quasi-one-dimensional nature of the model, disorder ultimately localizes the excitons, diminishing but not destroying the effects of supertransfer. When dephasing effects are included, we study the scaling of diffusion with both time and number of chromophores and observe that the transition from a coherent, ballistic regime to an incoherent, random-walk regime occurs at the same point as the change from supertransfer to classical scaling.
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Affiliation(s)
- D F Abasto
- Department of Physics and Astronomy and Center for Quantum Information Science and Technology, University of Southern California, Los Angeles, CA 90089-0484, USA
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35
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From red to blue to far-red in Lhca4: How does the protein modulate the spectral properties of the pigments? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:711-7. [DOI: 10.1016/j.bbabio.2012.02.030] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 02/22/2012] [Accepted: 02/23/2012] [Indexed: 10/28/2022]
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36
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Werwie M, Xu X, Haase M, Basché T, Paulsen H. Bio serves nano: biological light-harvesting complex as energy donor for semiconductor quantum dots. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:5810-8. [PMID: 22401299 DOI: 10.1021/la204970a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Light-harvesting complex (LHCII) of the photosynthetic apparatus in plants is attached to type-II core-shell CdTe/CdSe/ZnS nanocrystals (quantum dots, QD) exhibiting an absorption band at 710 nm and carrying a dihydrolipoic acid coating for water solubility. LHCII stays functional upon binding to the QD surface and enhances the light utilization of the QDs significantly, similar to its light-harvesting function in photosynthesis. Electronic excitation energy transfer of about 50% efficiency is shown by donor (LHCII) fluorescence quenching as well as sensitized acceptor (QD) emission and corroborated by time-resolved fluorescence measurements. The energy transfer efficiency is commensurable with the expected efficiency calculated according to Förster theory on the basis of the estimated donor-acceptor separation. Light harvesting is particularly efficient in the red spectral domain where QD absorption is relatively low. Excitation over the entire visible spectrum is further improved by complementing the biological pigments in LHCII with a dye attached to the apoprotein; the dye has been chosen to absorb in the "green gap" of the LHCII absorption spectrum and transfers its excitation energy ultimately to QD. This is the first report of a biological light-harvesting complex serving an inorganic semiconductor nanocrystal. Due to the charge separation between the core and the shell in type-II QDs the presented LHCII-QD hybrid complexes are potentially interesting for sensitized charge-transfer and photovoltaic applications.
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Affiliation(s)
- Mara Werwie
- Institut für Allgemeine Botanik, Johannes-Gutenberg-Universität Mainz, Mainz, Germany
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37
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Zucchelli G, Santabarbara S, Jennings RC. The Qy Absorption Spectrum of the Light-Harvesting Complex II As Determined by Structure-Based Analysis of Chlorophyll Macrocycle Deformations. Biochemistry 2012; 51:2717-36. [DOI: 10.1021/bi201677q] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Giuseppe Zucchelli
- CNR-Istituto di Biofisica, Sezione di Milano
and Dipartimento di Biologia, Università degli Studi di Milano, via Giovanni Celoria 26, 20133
Milano Italy
| | - Stefano Santabarbara
- CNR-Istituto di Biofisica, Sezione di Milano
and Dipartimento di Biologia, Università degli Studi di Milano, via Giovanni Celoria 26, 20133
Milano Italy
| | - Robert C. Jennings
- CNR-Istituto di Biofisica, Sezione di Milano
and Dipartimento di Biologia, Università degli Studi di Milano, via Giovanni Celoria 26, 20133
Milano Italy
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38
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Thilagam A. Non-Hermitian exciton dynamics in a photosynthetic unit system. J Chem Phys 2012; 136:065104. [DOI: 10.1063/1.3684654] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Novoderezhkin V, Marin A, van Grondelle R. Intra- and inter-monomeric transfers in the light harvesting LHCII complex: the Redfield-Förster picture. Phys Chem Chem Phys 2011; 13:17093-103. [PMID: 21866281 DOI: 10.1039/c1cp21079c] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We further develop the model of energy transfer in the LHCII trimer based on a quantitative fit of the linear spectra (including absorption (OD), linear dichroism (LD), circular dichroism (CD), and fluorescence (FL)) and transient absorption (TA) kinetics upon 650 nm and 662 nm excitation. The spectral shapes and relaxation/migration rates have been calculated using the combined Redfield-Förster approach capable of correctly describing fast relaxation within strongly coupled chlorophyll (Chl) a and b clusters and slow migration between them. Within each monomeric subunit of the trimeric complex there is fast (sub-ps) conversion from Chl's b to Chl's a at the stromal side accompanied by slow (>10 ps) equilibration between the stromal- and lumenal-side Chl a clusters in combination with slow (>13 ps) population of Chl's a from the 'bottleneck' Chl a604 site. The connection between monomeric subunits is determined by exciton coupling between the stromal-side Chl's b from the two adjacent subunits (Chl b601'-608-609 cluster) making a simultaneous fast (sub-ps) population of the Chl's a possible from both subunits. Final equilibration occurs via slow (>20 ps) migration between the Chl a clusters located on different monomeric subunits. This migration includes up-hill transfers from the red-most Chl a610-611-612 clusters located at the peripheral side in each subunit to the Chl a602-603 dimers located at the inner side of the trimeric LHCII complex.
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Affiliation(s)
- Vladimir Novoderezhkin
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Leninskie Gory, 119992, Moscow, Russia.
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40
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Croce R, van Amerongen H. Light-harvesting and structural organization of Photosystem II: From individual complexes to thylakoid membrane. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 104:142-53. [DOI: 10.1016/j.jphotobiol.2011.02.015] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 02/16/2011] [Accepted: 02/17/2011] [Indexed: 10/18/2022]
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41
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van Oort B, Maréchal A, Ruban AV, Robert B, Pascal AA, de Ruijter NCA, van Grondelle R, van Amerongen H. Different crystal morphologies lead to slightly different conformations of light-harvesting complex II as monitored by variations of the intrinsic fluorescence lifetime. Phys Chem Chem Phys 2011; 13:12614-22. [PMID: 21670839 DOI: 10.1039/c1cp20331b] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In 2005, it was found that the fluorescence of crystals of the major light-harvesting complex LHCII of green plants is significantly quenched when compared to the fluorescence of isolated LHCII (A. A. Pascal et al., Nature, 2005, 436, 134-137). The Raman spectrum of crystallized LHCII was also found to be different from that of isolated LHCII but very similar to that of aggregated LHCII, which has often been considered a good model system for studying nonphotochemical quenching (NPQ), the major protection mechanism of plants against photodamage in high light. It was proposed that in the crystal LHCII adopts a similar (quenching) conformation as during NPQ and indeed similar changes in the Raman spectrum were observed during NPQ in vivo (A. V. Ruban et al., Nature, 2007, 450, 575-579). We now compared the fluorescence of various types of crystals, differing in morphology and age. Each type gave rise to its own characteristic mono-exponential fluorescence lifetime, which was 5 to 10 times shorter than that of isolated LHCII. This indicates that fluorescence is not quenched by random impurities and packing defects (as proposed recently by T. Barros et al., EMBO Journal, 2009, 28, 298-306), but that LHCII adopts a particular structure in each crystal type, that leads to fluorescence quenching. Most interestingly, the extent of quenching appears to depend on the crystal morphology, indicating that also the crystal structure depends on this crystal morphology but at the moment no data are available to correlate the crystals' structural changes to changes in fluorescence lifetime.
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Affiliation(s)
- Bart van Oort
- VU University Amsterdam, Faculty of Sciences, Department of Physics and Astronomy, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
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42
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Wientjes E, van Stokkum IHM, van Amerongen H, Croce R. Excitation-energy transfer dynamics of higher plant photosystem I light-harvesting complexes. Biophys J 2011; 100:1372-80. [PMID: 21354411 DOI: 10.1016/j.bpj.2011.01.030] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 01/19/2011] [Indexed: 11/15/2022] Open
Abstract
Photosystem I (PSI) plays a major role in the light reactions of photosynthesis. In higher plants, PSI is composed of a core complex and four outer antennas that are assembled as two dimers, Lhca1/4 and Lhca2/3. Time-resolved fluorescence measurements on the isolated dimers show very similar kinetics. The intermonomer transfer processes are resolved using target analysis. They occur at rates similar to those observed in transfer to the PSI core, suggesting competition between the two transfer pathways. It appears that each dimer is adopting various conformations that correspond to different lifetimes and emission spectra. A special feature of the Lhca complexes is the presence of an absorption band at low energy, originating from an excitonic state of a chlorophyll dimer, mixed with a charge-transfer state. These low-energy bands have high oscillator strengths and they are superradiant in both Lhca1/4 and Lhca2/3. This challenges the view that the low-energy charge-transfer state always functions as a quencher in plant Lhc's and it also challenges previous interpretations of PSI kinetics. The very similar properties of the low-energy states of both dimers indicate that the organization of the involved chlorophylls should also be similar, in disagreement with the available structural data.
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Affiliation(s)
- Emilie Wientjes
- Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
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43
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Caffarri S, Broess K, Croce R, van Amerongen H. Excitation energy transfer and trapping in higher plant Photosystem II complexes with different antenna sizes. Biophys J 2011; 100:2094-103. [PMID: 21539776 PMCID: PMC3149253 DOI: 10.1016/j.bpj.2011.03.049] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 03/22/2011] [Accepted: 03/30/2011] [Indexed: 10/18/2022] Open
Abstract
We performed picosecond fluorescence measurements on well-defined Photosystem II (PSII) supercomplexes from Arabidopsis with largely varying antenna sizes. The average excited-state lifetime ranged from 109 ps for PSII core to 158 ps for the largest C(2)S(2)M(2) complex in 0.01% α-DM. Excitation energy transfer and trapping were investigated by coarse-grained modeling of the fluorescence kinetics. The results reveal a large drop in free energy upon charge separation (>700 cm(-1)) and a slow relaxation of the radical pair to an irreversible state (∼150 ps). Somewhat unexpectedly, we had to reduce the energy-transfer and charge-separation rates in complexes with decreasing size to obtain optimal fits. This strongly suggests that the antenna system is important for plant PSII integrity and functionality, which is supported by biochemical results. Furthermore, we used the coarse-grained model to investigate several aspects of PSII functioning. The excitation trapping time appears to be independent of the presence/absence of most of the individual contacts between light-harvesting complexes in PSII supercomplexes, demonstrating the robustness of the light-harvesting process. We conclude that the efficiency of the nonphotochemical quenching process is hardly dependent on the exact location of a quencher within the supercomplexes.
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Affiliation(s)
- Stefano Caffarri
- Aix Marseille Université, Laboratoire de Génétique et Biophysique des Plantes, Marseille, France
- CEA, DSV, iBEB, Marseille, France
- CNRS, UMR6191 Biologie Végétale et Microbiologie Environnementales, Marseille, France
| | - Koen Broess
- Wageningen University, Laboratory of Biophysics, Wageningen, The Netherlands
| | - Roberta Croce
- Groningen University, Groningen Biomolecular Sciences and Biotechnology Institute, Department of Biophysical Chemistry, Groningen, The Netherlands
| | - Herbert van Amerongen
- Wageningen University, Laboratory of Biophysics, Wageningen, The Netherlands
- Microspectroscopy Center, Wageningen, The Netherlands
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44
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Herascu N, Najafi M, Amunts A, Pieper J, Irrgang KD, Picorel R, Seibert M, Zazubovich V. Parameters of the protein energy landscapes of several light-harvesting complexes probed via spectral hole growth kinetics measurements. J Phys Chem B 2011; 115:2737-47. [PMID: 21391534 DOI: 10.1021/jp108775y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The parameters of barrier distributions on the protein energy landscape in the excited electronic state of the pigment/protein system have been determined by means of spectral hole burning for the lowest-energy pigments of CP43 core antenna complex and CP29 minor antenna complex of spinach Photosystem II (PS II) as well as of trimeric and monomeric LHCII complexes transiently associated with the pea Photosystem I (PS I) pool. All of these complexes exhibit sixty to several hundred times lower spectral hole burning yields as compared with molecular glassy solids previously probed by means of the hole growth kinetics measurements. Therefore, the entities (groups of atoms), which participate in conformational changes in protein, appear to be significantly larger and heavier than those in molecular glasses. No evidence of a small (∼1 cm(-1)) spectral shift tier of the spectral diffusion dynamics has been observed. Therefore, our data most likely reflect the true barrier distributions of the intact protein and not those related to the interface or surrounding host. Possible applications of the barrier distributions as well as the assignments of low-energy states of CP29 and LHCII are discussed in light of the above results.
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Affiliation(s)
- Nicoleta Herascu
- Department of Physics, Concordia University, Montreal, Quebec, Canada
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45
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The light-harvesting complexes of higher-plant Photosystem I: Lhca1/4 and Lhca2/3 form two red-emitting heterodimers. Biochem J 2011; 433:477-85. [PMID: 21083539 DOI: 10.1042/bj20101538] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The outer antenna of higher-plant PSI (Photosystem I) is composed of four complexes [Lhc (light-harvesting complex) a1-Lhca4] belonging to the light-harvesting protein family. Difficulties in their purification have so far prevented the determination of their properties and most of the knowledge about Lhcas has been obtained from the study of the in vitro reconstituted antennas. In the present study we were able to purify the native complexes, showing that Lhca2/3 and Lhca1/4 form two functional heterodimers. Both dimers show red-fluorescence emission with maxima around 730 nm, as in the intact PSI complex. This indicates that the dimers are in their native state and that LHCI-680, which was previously assumed to be part of the PSI antenna, does not represent the native state of the system. The data show that the light-harvesting properties of the two dimers are functionally identical, concerning absorption, long-wavelength emission and fluorescence quantum yield, whereas they differ in their high-light response. Implications of the present study for the understanding of the energy transfer process in PSI are discussed. Finally, the comparison of the properties of the native dimers with those of the reconstituted complexes demonstrates that all of the major properties of the Lhcas are reproduced in the in vitro systems.
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46
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Krumova SB, Laptenok SP, Borst JW, Ughy B, Gombos Z, Ajlani G, van Amerongen H. Monitoring photosynthesis in individual cells of Synechocystis sp. PCC 6803 on a picosecond timescale. Biophys J 2011; 99:2006-15. [PMID: 20858447 DOI: 10.1016/j.bpj.2010.07.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 07/09/2010] [Accepted: 07/13/2010] [Indexed: 01/20/2023] Open
Abstract
Picosecond fluorescence kinetics of wild-type (WT) and mutant cells of Synechocystis sp. PCC 6803, were studied at the ensemble level with a streak-camera and at the cell level using fluorescence-lifetime-imaging microscopy (FLIM). The FLIM measurements are in good agreement with the ensemble measurements, but they (can) unveil variations between and within cells. The BE mutant cells, devoid of photosystem II (PSII) and of the light-harvesting phycobilisomes, allowed the study of photosystem I (PSI) in vivo for the first time, and the observed 6-ps equilibration process and 25-ps trapping process are the same as found previously for isolated PSI. No major differences are detected between different cells. The PAL mutant cells, devoid of phycobilisomes, show four lifetimes: ∼20 ps (PSI and PSII), ∼80 ps, ∼440 ps, and 2.8 ns (all due to PSII), but not all cells are identical and variations in the kinetics are traced back to differences in the PSI/PSII ratio. Finally, FLIM measurements on WT cells reveal that in some cells or parts of cells, phycobilisomes are disconnected from PSI/PSII. It is argued that the FLIM setup used can become instrumental in unraveling photosynthetic regulation mechanisms in the future.
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Affiliation(s)
- S B Krumova
- Laboratory of Biophysics, Wageningen University, Wageningen, The Netherlands
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47
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Effect of xanthophyll composition on the chlorophyll excited state lifetime in plant leaves and isolated LHCII. Chem Phys 2010. [DOI: 10.1016/j.chemphys.2009.12.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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48
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van Oort B, Alberts M, de Bianchi S, Dall'Osto L, Bassi R, Trinkunas G, Croce R, van Amerongen H. Effect of antenna-depletion in Photosystem II on excitation energy transfer in Arabidopsis thaliana. Biophys J 2010; 98:922-31. [PMID: 20197046 DOI: 10.1016/j.bpj.2009.11.012] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 11/03/2009] [Accepted: 11/09/2009] [Indexed: 11/18/2022] Open
Abstract
The role of individual photosynthetic antenna complexes of Photosystem II (PSII) both in membrane organization and excitation energy transfer have been investigated. Thylakoid membranes from wild-type Arabidopsis thaliana, and three mutants lacking light-harvesting complexes CP24, CP26, or CP29, respectively, were studied by picosecond-fluorescence spectroscopy. By using different excitation/detection wavelength combinations it was possible for the first time, to our knowledge, to separate PSI and PSII fluorescence kinetics. The sub-100 ps component, previously ascribed entirely to PSI, turns out to be due partly to PSII. Moreover, the migration time of excitations from antenna to PSII reaction center (RC) was determined for the first time, to our knowledge, for thylakoid membranes. It is four times longer than for PSII-only membranes, due to additional antenna complexes, which are less well connected to the RC. The results in the absence of CP26 are very similar to those of wild-type, demonstrating that the PSII organization is not disturbed. However, the kinetics in the absence of CP29 and, especially, of CP24 show that a large fraction of the light-harvesting complexes becomes badly connected to the RCs. Interestingly, the excited-state lifetimes of the disconnected light-harvesting complexes seem to be substantially quenched.
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Passarini F, Wientjes E, Hienerwadel R, Croce R. Molecular basis of light harvesting and photoprotection in CP24: unique features of the most recent antenna complex. J Biol Chem 2009; 284:29536-46. [PMID: 19700403 DOI: 10.1074/jbc.m109.036376] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CP24 is a minor antenna complex of Photosystem II, which is specific for land plants. It has been proposed that this complex is involved in the process of excess energy dissipation, which protects plants from photodamage in high light conditions. Here, we have investigated the functional architecture of the complex, integrating mutation analysis with time-resolved spectroscopy. A comprehensive picture is obtained about the nature, the spectroscopic properties, and the role in the quenching in solution of the pigments in the individual binding sites. The lowest energy absorption band in the chlorophyll a region corresponds to chlorophylls 611/612, and it is not the site of quenching in CP24. Chlorophylls 613 and 614, which are present in the major light-harvesting complex of Photosystem appear to be absent in CP24. In contrast to all other light-harvesting complexes, CP24 is stable when the L1 carotenoid binding site is empty and upon mutations in the third helix, whereas mutations in the first helix strongly affect the folding/stability of the pigment-protein complex. The absence of lutein in L1 site does not have any effect on the quenching, whereas substitution of violaxanthin in the L2 site with lutein or zeaxanthin results in a complex with enhanced quenched fluorescence. Triplet-minus-singlet measurements indicate that zeaxanthin and lutein in site L2 are located closer to chlorophylls than violaxanthin, thus suggesting that they can act as direct quenchers via a strong interaction with a neighboring chlorophyll. The results provide the molecular basis for the zeaxanthin-dependent quenching in isolated CP24.
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Affiliation(s)
- Francesca Passarini
- Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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Barros T, Royant A, Standfuss J, Dreuw A, Kühlbrandt W. Crystal structure of plant light-harvesting complex shows the active, energy-transmitting state. EMBO J 2009; 28:298-306. [PMID: 19131972 PMCID: PMC2637333 DOI: 10.1038/emboj.2008.276] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 12/03/2008] [Indexed: 11/08/2022] Open
Abstract
Plants dissipate excess excitation energy as heat by non-photochemical quenching (NPQ). NPQ has been thought to resemble in vitro aggregation quenching of the major antenna complex, light harvesting complex of photosystem II (LHC-II). Both processes are widely believed to involve a conformational change that creates a quenching centre of two neighbouring pigments within the complex. Using recombinant LHC-II lacking the pigments implicated in quenching, we show that they have no particular role. Single crystals of LHC-II emit strong, orientation-dependent fluorescence with an emission maximum at 680 nm. The average lifetime of the main 680 nm crystal emission at 100 K is 1.31 ns, but only 0.39 ns for LHC-II aggregates under identical conditions. The strong emission and comparatively long fluorescence lifetimes of single LHC-II crystals indicate that the complex is unquenched, and that therefore the crystal structure shows the active, energy-transmitting state of LHC-II. We conclude that quenching of excitation energy in the light-harvesting antenna is due to the molecular interaction with external pigments in vitro or other pigment-protein complexes such as PsbS in vivo, and does not require a conformational change within the complex.
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Affiliation(s)
- Tiago Barros
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Antoine Royant
- Laboratoire de Cristallogenèse et Cristallographie des Protéines, Institut de Biologie Structurale J-P Ebel, UMR 5075 CNRS–CEA–UJF, Grenoble, France
- European Synchrotron Radiation Facility, Grenoble, France
| | - Jörg Standfuss
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Andreas Dreuw
- Institute for Physical and Theoretical Chemistry, Johann Wolfgang Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
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