1
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Wang D, Fiebig OC, Harris D, Toporik H, Ji Y, Chuang C, Nairat M, Tong AL, Ogren JI, Hart SM, Cao J, Sturgis JN, Mazor Y, Schlau-Cohen GS. Elucidating interprotein energy transfer dynamics within the antenna network from purple bacteria. Proc Natl Acad Sci U S A 2023; 120:e2220477120. [PMID: 37399405 PMCID: PMC10334754 DOI: 10.1073/pnas.2220477120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 04/21/2023] [Indexed: 07/05/2023] Open
Abstract
In photosynthesis, absorbed light energy transfers through a network of antenna proteins with near-unity quantum efficiency to reach the reaction center, which initiates the downstream biochemical reactions. While the energy transfer dynamics within individual antenna proteins have been extensively studied over the past decades, the dynamics between the proteins are poorly understood due to the heterogeneous organization of the network. Previously reported timescales averaged over such heterogeneity, obscuring individual interprotein energy transfer steps. Here, we isolated and interrogated interprotein energy transfer by embedding two variants of the primary antenna protein from purple bacteria, light-harvesting complex 2 (LH2), together into a near-native membrane disc, known as a nanodisc. We integrated ultrafast transient absorption spectroscopy, quantum dynamics simulations, and cryogenic electron microscopy to determine interprotein energy transfer timescales. By varying the diameter of the nanodiscs, we replicated a range of distances between the proteins. The closest distance possible between neighboring LH2, which is the most common in native membranes, is 25 Å and resulted in a timescale of 5.7 ps. Larger distances of 28 to 31 Å resulted in timescales of 10 to 14 ps. Corresponding simulations showed that the fast energy transfer steps between closely spaced LH2 increase transport distances by ∼15%. Overall, our results introduce a framework for well-controlled studies of interprotein energy transfer dynamics and suggest that protein pairs serve as the primary pathway for the efficient transport of solar energy.
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Affiliation(s)
- Dihao Wang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Olivia C. Fiebig
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Dvir Harris
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Hila Toporik
- School of Molecular Sciences, Arizona State University, Tempe, AZ85281
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ85281
| | - Yi Ji
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Chern Chuang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Muath Nairat
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Ashley L. Tong
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA02139
| | - John I. Ogren
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Stephanie M. Hart
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Jianshu Cao
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA02139
| | - James N. Sturgis
- LISM UMR 7255, CNRS and Aix-Marseille University, Marseille Cedex 913402, France
| | - Yuval Mazor
- School of Molecular Sciences, Arizona State University, Tempe, AZ85281
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ85281
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2
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Hu YY, Liu XL, Yao HD, Jiang YL, Li K, Chen MQ, Wang P, Zhang JP. PEG effects on excitonic properties of LH2 from Rhodobacter sphaeroides 2.4.1 in different environments. Chem Phys Lett 2023. [DOI: 10.1016/j.cplett.2023.140477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/01/2023]
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3
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Liu XL, Hu YY, Li K, Chen MQ, Wang P. Reconstituted LH2 in multilayer membranes induced by poly-L-lysine: structure of supramolecular and electronic states. ARAB J CHEM 2023. [DOI: 10.1016/j.arabjc.2023.104600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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4
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Brady NG, Qian S, Nguyen J, O'Neill HM, Bruce BD. Small angle neutron scattering and lipidomic analysis of a native, trimeric PSI-SMALP from a thermophilic cyanobacteria. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148596. [PMID: 35853496 PMCID: PMC10228149 DOI: 10.1016/j.bbabio.2022.148596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 06/05/2022] [Accepted: 07/11/2022] [Indexed: 01/21/2023]
Abstract
The use of styrene-maleic acid copolymers (SMAs) to produce membrane protein-containing nanodiscs without the initial detergent isolation has gained significant interest over the last decade. We have previously shown that a Photosystem I SMALP from the thermophilic cyanobacterium, Thermosynechococcus elongatus (PSI-SMALP), has much more rapid energy transfer and charge separation in vitro than detergent isolated PSI complexes. In this study, we have utilized small-angle neutron scattering (SANS) to better understand the geometry of these SMALPs. These techniques allow us to investigate the size and shape of these particles in their fully solvated state. Further, the particle's proteolipid core and detergent shell or copolymer belt can be interrogated separately using contrast variation, a capability unique to SANS. Here we report the dimensions of the Thermosynechococcus elongatus PSI-SMALP containing a PSI trimer. At ~1.5 MDa, PSI-SMALP is the largest SMALP to be isolated; our lipidomic analysis indicates it contains ~1300 lipids/per trimeric particle, >40-fold more than the PSI-DDM particle and > 100 fold more than identified in the 1JB0 crystal structure. Interestingly, the lipid composition to the PSI trimer in the PSI-SMALP differs significantly from bulk thylakoid composition, being enriched ~50 % in the anionic sulfolipid, SQDG. Finally, utilizing the contrast match point for the SMA 1440 copolymer, we also can observe the ~1 nm SMA copolymer belt surrounding this SMALP for the first time, consistent with most models of SMA organization.
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Affiliation(s)
- Nathan G Brady
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Shuo Qian
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; The Second Target Station Project, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Jon Nguyen
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Hugh M O'Neill
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Barry D Bruce
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA; Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA; Department of Microbiology, University of Tennessee, Knoxville, TN 37996, USA.
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5
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Pamu R, Khomami B, Mukherjee D. Observation of anomalous carotenoid and blind chlorophyll activations in photosystem I under synthetic membrane confinements. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183930. [PMID: 35398026 DOI: 10.1016/j.bbamem.2022.183930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 03/27/2022] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
The role of natural thylakoid membrane confinements in architecting the robust structural and electrochemical properties of PSI is not fully understood. Most PSI studies till date extract the proteins from their natural confinements that can lead to non-native conformations. Recently our group had successfully reconstituted PSI in synthetic lipid membranes using detergent-mediated liposome solubilizations. In this study, we investigate the alterations in chlorophylls and carotenoids interactions and reorganization in PSI based on spectral property changes induced by its confinement in anionic DPhPG and zwitterionic DPhPC phospholipid membranes. To this end, we employ a combination of absorption, fluorescence, and circular dichroism (CD) spectroscopic measurements. Our results indicate unique activation and alteration of photoresponses from the PSI carotenoid (Car) bands in PSI-DPhPG proteoliposomes that can tune the Excitation Energy Transfer (EET), otherwise absent in PSI at non-native environments. Specifically, we observe broadband light harvesting via enhanced absorption in the otherwise non-absorptive green region (500-580 nm) of the Chlorophylls (Chl) along with ~64% increase in the full-width half maximum of the Qy band (650-720 nm). The CD results indicate enhanced Chl-Chl and Chl-Car interactions along with conformational changes in protein secondary structures. Such distinct changes in the Car and Chl bands are not observed in PSI confined in DPhPC. The fundamental insights into membrane microenvironments tailoring PSI subunits reorganization and interactions provide novel strategies for tuning photoexcitation processes and rational designing of biotic-abiotic interfaces in PSI-based photoelectrochemical energy conversion systems.
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Affiliation(s)
- Ravi Pamu
- Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, Knoxville, TN 37996, USA; Nano-BioMaterials Laboratory for Energy, Energetics & Environment (nbml-E3), University of Tennessee, Knoxville, TN 37996, USA; Sustainable Energy Education and Research Center (SEERC), University of Tennessee, Knoxville, TN 37996, USA
| | - Bamin Khomami
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA; Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, Knoxville, TN 37996, USA; Sustainable Energy Education and Research Center (SEERC), University of Tennessee, Knoxville, TN 37996, USA.
| | - Dibyendu Mukherjee
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA; Nano-BioMaterials Laboratory for Energy, Energetics & Environment (nbml-E3), University of Tennessee, Knoxville, TN 37996, USA; Sustainable Energy Education and Research Center (SEERC), University of Tennessee, Knoxville, TN 37996, USA.
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6
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Knox PP, Lukashev EP, Korvatovskiy BN, Strakhovskaya MG, Makhneva ZK, Bol'shakov MA, Paschenko VZ. Disproportionate effect of cationic antiseptics on the quantum yield and fluorescence lifetime of bacteriochlorophyll molecules in the LH1-RC complex of R. rubrum chromatophores. PHOTOSYNTHESIS RESEARCH 2022; 153:103-112. [PMID: 35277801 DOI: 10.1007/s11120-022-00909-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 02/26/2022] [Indexed: 06/14/2023]
Abstract
Photosynthetic membrane complexes of purple bacteria are convenient and informative macromolecular systems for studying the mechanisms of action of various physicochemical factors on the functioning of catalytic proteins both in an isolated state and as part of functional membranes. In this work, we studied the effect of cationic antiseptics (chlorhexidine, picloxydine, miramistin, and octenidine) on the fluorescence intensity and the efficiency of energy transfer from the light-harvesting LH1 complex to the reaction center (RC) of Rhodospirillum rubrum chromatophores. The effect of antiseptics on the fluorescence intensity and the energy transfer increased in the following order: chlorhexidine, picloxydine, miramistin, octenidine. The most pronounced changes in the intensity and lifetime of fluorescence were observed with the addition of miramistin and octenidine. At the same concentration of antiseptics, the increase in fluorescence intensity was 2-3 times higher than the increase in its lifetime. It is concluded that the addition of antiseptics decreases the efficiency of the energy migration LH1 → RC and increases the fluorescence rate constant kfl. We associate the latter with a change in the polarization of the microenvironment of bacteriochlorophyll molecules upon the addition of charged antiseptic molecules. A possible mechanism of antiseptic action on R. rubrum chromatophores is considered. This work is a continuation of the study of the effect of antiseptics on the energy transfer and fluorescence intensity in chromatophores of purple bacteria published earlier in Photosynthesis Research (Strakhovskaya et al. in Photosyn Res 147:197-209, 2021).
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Affiliation(s)
- Peter P Knox
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russian Federation, 119234
| | - Eugene P Lukashev
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russian Federation, 119234
| | - Boris N Korvatovskiy
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russian Federation, 119234
| | - Marina G Strakhovskaya
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russian Federation, 119234.
| | - Zoja K Makhneva
- Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences", Pushchino, Russian Federation, 142290
| | - Maxim A Bol'shakov
- Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences", Pushchino, Russian Federation, 142290
| | - Vladimir Z Paschenko
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russian Federation, 119234
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7
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Son M, Moya R, Pinnola A, Bassi R, Schlau-Cohen GS. Protein-Protein Interactions Induce pH-Dependent and Zeaxanthin-Independent Photoprotection in the Plant Light-Harvesting Complex, LHCII. J Am Chem Soc 2021; 143:17577-17586. [PMID: 34648708 DOI: 10.1021/jacs.1c07385] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Plants use energy from the sun yet also require protection against the generation of deleterious photoproducts from excess energy. Photoprotection in green plants, known as nonphotochemical quenching (NPQ), involves thermal dissipation of energy and is activated by a series of interrelated factors: a pH drop in the lumen, accumulation of the carotenoid zeaxanthin (Zea), and formation of arrays of pigment-containing antenna complexes. However, understanding their individual contributions and their interactions has been challenging, particularly for the antenna arrays, which are difficult to manipulate in vitro. Here, we achieved systematic and discrete control over the array size for the principal antenna complex, light-harvesting complex II, using near-native in vitro membranes called nanodiscs. Each of the factors had a distinct influence on the level of dissipation, which was characterized by measurements of fluorescence quenching and ultrafast chlorophyll-to-carotenoid energy transfer. First, an increase in array size led to a corresponding increase in dissipation; the dramatic changes in the chlorophyll dynamics suggested that this is due to an allosteric conformational change of the protein. Second, a pH drop increased dissipation but exclusively in the presence of protein-protein interactions. Third, no Zea dependence was identified which suggested that Zea regulates a distinct aspect of NPQ. Collectively, these results indicate that each factor provides a separate type of control knob for photoprotection, which likely enables a flexible and tunable response to solar fluctuations.
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Affiliation(s)
- Minjung Son
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Raymundo Moya
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alberta Pinnola
- Department of Biology and Biotechnology, University of Pavia, 27100 Pavia, Italy
| | - Roberto Bassi
- Department of Biotechnology, University of Verona, 37134 Verona, Italy.,Accademia Nazionale di Lincei, 00165 Rome, Italy
| | - Gabriela S Schlau-Cohen
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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8
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Hancock AM, Son M, Nairat M, Wei T, Jeuken LJC, Duffy CDP, Schlau-Cohen GS, Adams PG. Ultrafast energy transfer between lipid-linked chromophores and plant light-harvesting complex II. Phys Chem Chem Phys 2021; 23:19511-19524. [PMID: 34524278 PMCID: PMC8442836 DOI: 10.1039/d1cp01628h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Light-Harvesting Complex II (LHCII) is a membrane protein found in plant chloroplasts that has the crucial role of absorbing solar energy and subsequently performing excitation energy transfer to the reaction centre subunits of Photosystem II. LHCII provides strong absorption of blue and red light, however, it has minimal absorption in the green spectral region where solar irradiance is maximal. In a recent proof-of-principle study, we enhanced the absorption in this spectral range by developing a biohybrid system where LHCII proteins together with lipid-linked Texas Red (TR) chromophores were assembled into lipid membrane vesicles. The utility of these systems was limited by significant LHCII quenching due to protein-protein interactions and heterogeneous lipid structures. Here, we organise TR and LHCII into a lipid nanodisc, which provides a homogeneous, well-controlled platform to study the interactions between TR molecules and single LHCII complexes. Fluorescence spectroscopy determined that TR-to-LHCII energy transfer has an efficiency of at least 60%, resulting in a 262% enhancement of LHCII fluorescence in the 525-625 nm range, two-fold greater than in the previous system. Ultrafast transient absorption spectroscopy revealed two time constants of 3.7 and 128 ps for TR-to-LHCII energy transfer. Structural modelling and theoretical calculations indicate that these timescales correspond to TR-lipids that are loosely- or tightly-associated with the protein, respectively, with estimated TR-to-LHCII separations of ∼3.5 nm and ∼1 nm. Overall, we demonstrate that a nanodisc-based biohybrid system provides an idealised platform to explore the photophysical interactions between extrinsic chromophores and membrane proteins with potential applications in understanding more complex natural or artificial photosynthetic systems.
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Affiliation(s)
- Ashley M Hancock
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK. .,Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Minjung Son
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
| | - Muath Nairat
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
| | - Tiejun Wei
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Lars J C Jeuken
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.,Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.,Leiden Institute of Chemistry, Leiden University, 2300 RA Leiden, The Netherlands
| | - Christopher D P Duffy
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Gabriela S Schlau-Cohen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
| | - Peter G Adams
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK. .,Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
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9
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Onizhuk M, Sohoni S, Galli G, Engel GS. Spatial Patterns of Light-Harvesting Antenna Complex Arrangements Tune the Transfer-to-Trap Efficiency of Excitons in Purple Bacteria. J Phys Chem Lett 2021; 12:6967-6973. [PMID: 34283617 DOI: 10.1021/acs.jpclett.1c01537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In photosynthesis, the efficiency with which a photogenerated exciton reaches the reaction center is dictated by chromophore energies and the arrangement of chromophores in the supercomplex. Here, we explore the interplay between the arrangement of light-harvesting antennae and the efficiency of exciton transport in purple bacterial photosynthesis. Using a Miller-Abrahams-based exciton hopping model, we compare different arrangements of light-harvesting proteins on the intracytoplasmic membrane. We find that arrangements with aggregated LH1s have a higher efficiency than arrangements with randomly distributed LH1s in a wide range of physiological light fluences. This effect is robust to the introduction of defects on the intracytoplasmic membrane. Our result explains the absence of species with aggregated LH1 arrangements in low-light niches and the large increase seen in the expression of LH1 dimer complexes in high fluences. We suggest that the effect seen in our study is an adaptive strategy toward solar light fluence across different purple bacterial species.
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Affiliation(s)
- Mykyta Onizhuk
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
| | - Siddhartha Sohoni
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
- James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
- The Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
| | - Giulia Galli
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
- Materials Science Division and Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Gregory S Engel
- Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, United States
- James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
- The Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
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10
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Strakhovskaya MG, Lukashev EP, Korvatovskiy BN, Kholina EG, Seifullina NK, Knox PP, Paschenko VZ. The effect of some antiseptic drugs on the energy transfer in chromatophore photosynthetic membranes of purple non-sulfur bacteria Rhodobacter sphaeroides. PHOTOSYNTHESIS RESEARCH 2021; 147:197-209. [PMID: 33389445 PMCID: PMC7778420 DOI: 10.1007/s11120-020-00807-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Chromatophores of purple non-sulfur bacteria (PNSB) are invaginations of the cytoplasmic membrane that contain a relatively simple system of light-harvesting protein-pigment complexes, a photosynthetic reaction center (RC), a cytochrome complex, and ATP synthase, which transform light energy into the energy of synthesized ATP. The high content of negatively charged phosphatidylglycerol (PG) and cardiolipin (CL) in PNSB chromatophore membranes makes these structures potential targets that bind cationic antiseptics. We used the methods of stationary and kinetic fluorescence spectroscopy to study the effect of some cationic antiseptics (chlorhexidine, picloxydine, miramistin, and octenidine at concentrations up to 100 μM) on the spectral and kinetic characteristics of the components of the photosynthetic apparatus of Rhodobacter sphaeroides chromatophores. Here we present the experimental data on the reduced efficiency of light energy conversion in the chromatophore membranes isolated from the photosynthetic bacterium Rb. sphaeroides in the presence of cationic antiseptics. The addition of antiseptics did not affect the energy transfer between the light-harvesting LH1 complex and reaction center (RC). However, it significantly reduced the efficiency of the interaction between the LH2 and LH1 complexes. The effect was maximal with 100 μM octenidine. It has been proved that molecules of cationic antiseptics, which apparently bind to the heads of negatively charged cardiolipin molecules located in the rings of light-harvesting pigments on the cytoplasmic surface of the chromatophores, can disturb the optimal conditions for efficient energy migration in chromatophore membranes.
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Affiliation(s)
- Marina G Strakhovskaya
- Biophysics Department, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia, 119234.
- Federal Scientific and Clinical Center of Specialized Types of Medical Care and Medical Technologies of the Federal Medical and Biological Agency of Russia, Moscow, Russian Federation.
| | - Eugene P Lukashev
- Biophysics Department, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Boris N Korvatovskiy
- Biophysics Department, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Ekaterina G Kholina
- Biophysics Department, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Nuranija Kh Seifullina
- Biophysics Department, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Peter P Knox
- Biophysics Department, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
| | - Vladimir Z Paschenko
- Biophysics Department, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia, 119234
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11
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Thyrhaug E, Schröter M, Bukartė E, Kühn O, Cogdell R, Hauer J, Zigmantas D. Intraband dynamics and exciton trapping in the LH2 complex of Rhodopseudomonas acidophila. J Chem Phys 2021; 154:045102. [PMID: 33514092 DOI: 10.1063/5.0033802] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Over the last several decades, the light-harvesting protein complexes of purple bacteria have been among the most popular model systems for energy transport in excitonic systems in the weak and intermediate intermolecular coupling regime. Despite this extensive body of scientific work, significant questions regarding the excitonic states and the photo-induced dynamics remain. Here, we address the low-temperature electronic structure and excitation dynamics in the light-harvesting complex 2 of Rhodopseudomonas acidophila by two-dimensional electronic spectroscopy. We find that, although at cryogenic temperature energy relaxation is very rapid, exciton mobility is limited over a significant range of excitation energies. This points to the presence of a sub-200 fs, spatially local energy-relaxation mechanism and suggests that local trapping might contribute substantially more in cryogenic experiments than under physiological conditions where the thermal energy is comparable to or larger than the static disorder.
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Affiliation(s)
- Erling Thyrhaug
- Dynamical Spectroscopy, Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748 Garching b. Munich, Germany
| | - Marco Schröter
- Chemical Physics, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Eglė Bukartė
- Chemical Physics, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Oliver Kühn
- Institute of Physics, University of Rostock, Albert Einstein Straße 23-24, 18059 Rostock, Germany
| | - Richard Cogdell
- Institute of Molecular, Cell and Systems Biology, University of Glasgow, Room 402 Davidson Building, Glasgow G12 8QQ, Scotland
| | - Jürgen Hauer
- Dynamical Spectroscopy, Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748 Garching b. Munich, Germany
| | - Donatas Zigmantas
- Chemical Physics, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
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12
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Observation of dissipative chlorophyll-to-carotenoid energy transfer in light-harvesting complex II in membrane nanodiscs. Nat Commun 2020; 11:1295. [PMID: 32157079 PMCID: PMC7064482 DOI: 10.1038/s41467-020-15074-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 02/17/2020] [Indexed: 11/08/2022] Open
Abstract
Plants prevent photodamage under high light by dissipating excess energy as heat. Conformational changes of the photosynthetic antenna complexes activate dissipation by leveraging the sensitivity of the photophysics to the protein structure. The mechanisms of dissipation remain debated, largely due to two challenges. First, because of the ultrafast timescales and large energy gaps involved, measurements lacked the temporal or spectral requirements. Second, experiments have been performed in detergent, which can induce non-native conformations, or in vivo, where contributions from homologous antenna complexes cannot be disentangled. Here, we overcome both challenges by applying ultrabroadband two-dimensional electronic spectroscopy to the principal antenna complex, LHCII, in a near-native membrane. Our data provide evidence that the membrane enhances two dissipative pathways, one of which is a previously uncharacterized chlorophyll-to-carotenoid energy transfer. Our results highlight the sensitivity of the photophysics to local environment, which may control the balance between light harvesting and dissipation in vivo.
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13
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Tong AL, Fiebig OC, Nairat M, Harris D, Giansily M, Chenu A, Sturgis JN, Schlau-Cohen GS. Comparison of the Energy-Transfer Rates in Structural and Spectral Variants of the B800-850 Complex from Purple Bacteria. J Phys Chem B 2020; 124:1460-1469. [PMID: 31971387 DOI: 10.1021/acs.jpcb.9b11899] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photosynthetic light harvesting can occur with a remarkable near-unity quantum efficiency. The B800-850 complex, also known as light-harvesting complex 2 (LH2), is the primary light-harvesting complex in purple bacteria and has been extensively studied as a model system. The bacteriochlorophylls of the B800-850 complex are organized into two concentric rings, known as the B800 and B850 rings. However, depending on the species and growth conditions, the number of constituent subunits, the pigment geometry, and the absorption energies vary. While the dynamics of some B800-850 variants have been exhaustively characterized, others have not been measured. Furthermore, a direct and simultaneous comparison of how both structural and spectral differences between variants affect these dynamics has not been performed. In this work, we utilize ultrafast transient absorption measurements to compare the B800 to B850 energy-transfer rates in the B800-850 complex as a function of the number of subunits, geometry, and absorption energies. The nonameric B800-850 complex from Rhodobacter (Rb.) sphaeroides is 40% faster than the octameric B800-850 complex from Rhodospirillum (Rs.) molischianum, consistent with structure-based predictions. In contrast, the blue-shifted B800-820 complex from Rs. molischianum is only 20% faster than the B800-850 complex from Rs. molischianum despite an increase in the spectral overlap between the rings that would be expected to produce a larger increase in the energy-transfer rate. These measurements support current models that contain dark, higher-lying excitonic states to bridge the energy gap between rings, thereby maintaining similar energy-transfer dynamics. Overall, these results demonstrate that energy-transfer dynamics in the B800-850 complex are robust to the spectral and structural variations between species used to optimize energy capture and flow in purple bacteria.
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Affiliation(s)
- Ashley L Tong
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Olivia C Fiebig
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Muath Nairat
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Dvir Harris
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Marcel Giansily
- LISM UMR 7255 , CNRS and Aix-Marseille University , 31 Chemin Joseph Aiguier , Marseille Cedex 9 13402 , France
| | - Aurélia Chenu
- Donostia International Physics Center , E-20018 San Sebastián , Spain.,Ikerbasque, Basque Foundation for Science , E-48013 Bilbao , Spain
| | - James N Sturgis
- LISM UMR 7255 , CNRS and Aix-Marseille University , 31 Chemin Joseph Aiguier , Marseille Cedex 9 13402 , France
| | - Gabriela S Schlau-Cohen
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
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14
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Singharoy A, Maffeo C, Delgado-Magnero KH, Swainsbury DJK, Sener M, Kleinekathöfer U, Vant JW, Nguyen J, Hitchcock A, Isralewitz B, Teo I, Chandler DE, Stone JE, Phillips JC, Pogorelov TV, Mallus MI, Chipot C, Luthey-Schulten Z, Tieleman DP, Hunter CN, Tajkhorshid E, Aksimentiev A, Schulten K. Atoms to Phenotypes: Molecular Design Principles of Cellular Energy Metabolism. Cell 2019; 179:1098-1111.e23. [PMID: 31730852 PMCID: PMC7075482 DOI: 10.1016/j.cell.2019.10.021] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 09/04/2019] [Accepted: 10/21/2019] [Indexed: 01/01/2023]
Abstract
We report a 100-million atom-scale model of an entire cell organelle, a photosynthetic chromatophore vesicle from a purple bacterium, that reveals the cascade of energy conversion steps culminating in the generation of ATP from sunlight. Molecular dynamics simulations of this vesicle elucidate how the integral membrane complexes influence local curvature to tune photoexcitation of pigments. Brownian dynamics of small molecules within the chromatophore probe the mechanisms of directional charge transport under various pH and salinity conditions. Reproducing phenotypic properties from atomistic details, a kinetic model evinces that low-light adaptations of the bacterium emerge as a spontaneous outcome of optimizing the balance between the chromatophore's structural integrity and robust energy conversion. Parallels are drawn with the more universal mitochondrial bioenergetic machinery, from whence molecular-scale insights into the mechanism of cellular aging are inferred. Together, our integrative method and spectroscopic experiments pave the way to first-principles modeling of whole living cells.
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Affiliation(s)
- Abhishek Singharoy
- School of Molecular Sciences, Center for Applied Structural Discovery, Arizona State University at Tempe, Tempe, AZ 85282, USA.
| | - Christopher Maffeo
- Department of Physics, NSF Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Karelia H Delgado-Magnero
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Melih Sener
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ulrich Kleinekathöfer
- Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
| | - John W Vant
- School of Molecular Sciences, Center for Applied Structural Discovery, Arizona State University at Tempe, Tempe, AZ 85282, USA
| | - Jonathan Nguyen
- School of Molecular Sciences, Center for Applied Structural Discovery, Arizona State University at Tempe, Tempe, AZ 85282, USA
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Barry Isralewitz
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ivan Teo
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Danielle E Chandler
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - John E Stone
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - James C Phillips
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Taras V Pogorelov
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemistry, School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - M Ilaria Mallus
- Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
| | - Christophe Chipot
- Department of Physics, NSF Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Laboratoire International Associé CNRS-UIUC, UMR 7019, Université de Lorraine, 54506 Vandœuvre-lès-Nancy, France
| | - Zaida Luthey-Schulten
- Department of Physics, NSF Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemistry, School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - D Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK.
| | - Emad Tajkhorshid
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Departments of Biochemistry, Chemistry, Bioengineering, and Pharmacology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Aleksei Aksimentiev
- Department of Physics, NSF Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Klaus Schulten
- Department of Physics, NSF Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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15
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Hancock AM, Meredith SA, Connell SD, Jeuken LJC, Adams PG. Proteoliposomes as energy transferring nanomaterials: enhancing the spectral range of light-harvesting proteins using lipid-linked chromophores. NANOSCALE 2019; 11:16284-16292. [PMID: 31465048 DOI: 10.1039/c9nr04653d] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Bio-hybrid nanomaterials have great potential for combining the most desirable aspects of biomolecules and the contemporary concepts of nanotechnology to create highly efficient light-harvesting materials. Light-harvesting proteins are optimized to absorb and transfer solar energy with remarkable efficiency but have a spectral range that is limited by their natural pigment complement. Herein, we present the development of model membranes ("proteoliposomes") in which the absorption range of the membrane protein Light-Harvesting Complex II (LHCII) is effectively enhanced by the addition of lipid-tethered Texas Red (TR) chromophores. Energy transfer from TR to LHCII is observed with up to 94% efficiency and increased LHCII fluorescence of up to three-fold when excited in the region of lowest natural absorption. The new self-assembly procedure offers the modularity to control the concentrations incorporated of TR and LHCII, allowing energy transfer and fluorescence to be tuned. Fluorescence Lifetime Imaging Microscopy provides single-proteoliposome-level quantification of energy transfer efficiency and confirms that functionality is retained on surfaces. Designer proteoliposomes could act as a controllable light-harvesting nanomaterial and are a promising step in the development of bio-hybrid light-harvesting systems.
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Affiliation(s)
- Ashley M Hancock
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK. and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Sophie A Meredith
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK. and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Simon D Connell
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK. and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Lars J C Jeuken
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK and School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Peter G Adams
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK. and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
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16
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Dodin A, Brumer P. Light-induced processes in nature: Coherences in the establishment of the nonequilibrium steady state in model retinal isomerization. J Chem Phys 2019; 150:184304. [DOI: 10.1063/1.5092981] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Amro Dodin
- Chemical Physics Theory Group, Department of Chemistry, and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Paul Brumer
- Chemical Physics Theory Group, Department of Chemistry, and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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17
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Daskalakis V. Protein-protein interactions within photosystem II under photoprotection: the synergy between CP29 minor antenna, subunit S (PsbS) and zeaxanthin at all-atom resolution. Phys Chem Chem Phys 2018; 20:11843-11855. [PMID: 29658553 DOI: 10.1039/c8cp01226a] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The assembly and disassembly of protein complexes within cells are crucial life-sustaining processes. In photosystem II (PSII) of higher plants, there is a delicate yet obscure balance between light harvesting and photo-protection under fluctuating light conditions, that involves protein-protein complexes. Recent breakthroughs in molecular dynamics (MD) simulations are combined with new approaches herein to provide structural and energetic insight into such a complex between the CP29 minor antenna and the PSII subunit S (PsbS). The microscopic model involves extensive sampling of bound and dissociated states at atomic resolution in the presence of photo-protective zeaxanthin (Zea), and reveals well defined protein-protein cross-sections. The complex is placed within PSII, and macroscopic connections are emerging (PsbS-CP29-CP24-CP47) along the energy transfer pathways from the antenna to the PSII core. These connections explain macroscopic observations in the literature, while the previously obscured atomic scale details are now revealed. The implications of these findings are discussed in the context of the Non-Photochemical Quenching (NPQ) of chlorophyll fluorescence, the down-regulatory mechanism of photosynthesis, that enables the protection of PSII against excess excitation load. Zea is found at the PsbS-CP29 cross-section and a pH-dependent equilibrium between PsbS dimer/monomers and the PsbS-CP29 dissociation/association is identified as the target for engineering tolerant plants with increased crop and biomass yields. Finally, the new MD based approaches can be used to probe protein-protein interactions in general, and the PSII structure provided can initiate large scale molecular simulations of the photosynthetic apparatus, under NPQ conditions.
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Affiliation(s)
- Vangelis Daskalakis
- Department of Environmental Science and Technology, Cyprus University of Technology (CUT), 30 Archbishop Kyprianou Str., 3603, Limassol, Cyprus.
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