1
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Sardar S, Caferri R, Camargo FVA, Capaldi S, Ghezzi A, Dall'Osto L, D'Andrea C, Cerullo G, Bassi R. Site-Directed Mutagenesis of the Chlorophyll-Binding Sites Modulates Excited-State Lifetime and Chlorophyll-Xanthophyll Energy Transfer in the Monomeric Light-Harvesting Complex CP29. J Phys Chem Lett 2024; 15:3149-3158. [PMID: 38478725 DOI: 10.1021/acs.jpclett.3c02900] [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: 03/22/2024]
Abstract
We combine site-directed mutagenesis with picosecond time-resolved fluorescence and femtosecond transient absorption (TA) spectroscopies to identify excitation energy transfer (EET) processes between chlorophylls (Chls) and xanthophylls (Xant) in the minor antenna complex CP29 assembled inside nanodiscs, which result in quenching. When compared to WT CP29, a longer lifetime was observed in the A2 mutant, missing Chl a612, which closely interacts with Xant Lutein in site L1. Conversely, a shorter lifetime was obtained in the A5 mutant, in which the interaction between Chl a603 and Chl a609 is strengthened, shifting absorption to lower energy and enhancing Chl-Xant EET. Global analysis of TA data indicated that EET from Chl a Qy to a Car dark state S* is active in both the A2 and A5 mutants and that their rate constants are modulated by mutations. Our study provides experimental evidence that multiple Chl-Xant interactions are involved in the quenching activity of CP29.
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Affiliation(s)
- Samim Sardar
- Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia, Via Rubattino 81, 20134 Milan, Italy
| | - Roberto Caferri
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Franco V A Camargo
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza L. da Vinci 32, 20133 Milano, Italy
| | - Stefano Capaldi
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Alberto Ghezzi
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy
| | - Luca Dall'Osto
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Cosimo D'Andrea
- Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia, Via Rubattino 81, 20134 Milan, Italy
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy
| | - Giulio Cerullo
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza L. da Vinci 32, 20133 Milano, Italy
- Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy
| | - Roberto Bassi
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
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2
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Li DH, Wilson S, Mastroianni G, Ruban AV. Altered lipid acyl chain length controls energy dissipation in light-harvesting complex II proteoliposomes by hydrophobic mismatch. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2023; 246:112758. [PMID: 37531665 DOI: 10.1016/j.jphotobiol.2023.112758] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 08/04/2023]
Abstract
In plants, the major light-harvesting antenna complex (LHCII) is vital for both light harvesting and photoprotection in photosystem II. Previously, we proposed that the thylakoid membrane itself could switch LHCII into the photoprotective state, qE, via a process known as hydrophobic mismatch. The decrease in the membrane thickness that followed the formation of ΔpH was a key fact that prompted this idea. To test this, we made proteoliposomes from lipids with altered acyl chain length (ACL). Here, we show that ACL regulates the average chlorophyll fluorescence lifetime of LHCII. For liposomes made of lipids with an ACL of 18 carbons, the lifetime was ∼2 ns, like that for the thylakoid membrane. Furthermore, LHCII appears to be quenched in proteoliposomes with an ACL both shorter and longer than 18 carbons. The proteoliposomes made of short ACL lipids display structural heterogeneity revealing two quenched conformations of LHCII, each having characteristic 77 K fluorescence spectra. One conformation spectrally resembles isolated LHCII aggregates, whilst the other resembles LHCII immobilized in polyacrylamide gels. Overall, the decrease in the ACL appears to produce quenched conformations of LHCII, which renders plausible the idea that the trigger of qE is the hydrophobic mismatch.
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Affiliation(s)
- Dan-Hong Li
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
| | - Sam Wilson
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
| | - Giulia Mastroianni
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
| | - Alexander V Ruban
- Department of Biochemistry, School of Biological and Behavioural Sciences, Queen Mary University of London, London E1 4NS, United Kingdom.
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3
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Ruan M, Li H, Zhang Y, Zhao R, Zhang J, Wang Y, Gao J, Wang Z, Wang Y, Sun D, Ding W, Weng Y. Cryo-EM structures of LHCII in photo-active and photo-protecting states reveal allosteric regulation of light harvesting and excess energy dissipation. NATURE PLANTS 2023; 9:1547-1557. [PMID: 37653340 DOI: 10.1038/s41477-023-01500-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 07/26/2023] [Indexed: 09/02/2023]
Abstract
The major light-harvesting complex of photosystem II (LHCII) has a dual regulatory function in a process called non-photochemical quenching to avoid the formation of reactive oxygen. LHCII undergoes reversible conformation transitions to switch between a light-harvesting state for excited-state energy transfer and an energy-quenching state for dissipating excess energy under full sunshine. Here we report cryo-electron microscopy structures of LHCII in membrane nanodiscs, which mimic in vivo LHCII, and in detergent solution at pH 7.8 and 5.4, respectively. We found that, under low pH conditions, the salt bridges at the lumenal side of LHCII are broken, accompanied by the formation of two local α-helices on the lumen side. The formation of α-helices in turn triggers allosterically global protein conformational change, resulting in a smaller crossing angle between transmembrane helices. The fluorescence decay rates corresponding to different conformational states follow the Dexter energy transfer mechanism with a characteristic transition distance of 5.6 Å between Lut1 and Chl612. The experimental observations are consistent with the computed electronic coupling strengths using multistate density function theory.
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Affiliation(s)
- Meixia Ruan
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hao Li
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Ying Zhang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ruoqi Zhao
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Jun Zhang
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Yingjie Wang
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China
| | - Jiali Gao
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China.
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen, China.
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, MN, USA.
| | - Zhuan Wang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Yumei Wang
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Dapeng Sun
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Wei Ding
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Yuxiang Weng
- Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
- Songshan Lake Materials Laboratory, Dongguan, China.
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4
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Elias E, Liguori N, Croce R. The origin of pigment-binding differences in CP29 and LHCII: the role of protein structure and dynamics. PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES : OFFICIAL JOURNAL OF THE EUROPEAN PHOTOCHEMISTRY ASSOCIATION AND THE EUROPEAN SOCIETY FOR PHOTOBIOLOGY 2023:10.1007/s43630-023-00368-7. [PMID: 36740636 DOI: 10.1007/s43630-023-00368-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 01/13/2023] [Indexed: 02/07/2023]
Abstract
The first step of photosynthesis in plants is performed by the light-harvesting complexes (LHC), a large family of pigment-binding proteins embedded in the photosynthetic membranes. These complexes are conserved across species, suggesting that each has a distinct role. However, they display a high degree of sequence homology and their static structures are almost identical. What are then the structural features that determine their different properties? In this work, we compared the two best-characterized LHCs of plants: LHCII and CP29. Using molecular dynamics simulations, we could rationalize the difference between them in terms of pigment-binding properties. The data also show that while the loops between the helices are very flexible, the structure of the transmembrane regions remains very similar in the crystal and the membranes. However, the small structural differences significantly affect the excitonic coupling between some pigment pairs. Finally, we analyzed in detail the structure of the long N-terminus of CP29, showing that it is structurally stable and it remains on top of the membrane even in the absence of other proteins. Although the structural changes upon phosphorylation are minor, they can explain the differences in the absorption properties of the pigments observed experimentally.
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Affiliation(s)
- Eduard Elias
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Nicoletta Liguori
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Roberta Croce
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
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5
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Hancock AM, Swainsbury DJK, Meredith SA, Morigaki K, Hunter CN, Adams PG. Enhancing the spectral range of plant and bacterial light-harvesting pigment-protein complexes with various synthetic chromophores incorporated into lipid vesicles. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 237:112585. [PMID: 36334507 DOI: 10.1016/j.jphotobiol.2022.112585] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/16/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022]
Abstract
The Light-Harvesting (LH) pigment-protein complexes found in photosynthetic organisms have the role of absorbing solar energy with high efficiency and transferring it to reaction centre complexes. LH complexes contain a suite of pigments that each absorb light at specific wavelengths, however, the natural combinations of pigments within any one protein complex do not cover the full range of solar radiation. Here, we provide an in-depth comparison of the relative effectiveness of five different organic "dye" molecules (Texas Red, ATTO, Cy7, DiI, DiR) for enhancing the absorption range of two different LH membrane protein complexes (the major LHCII from plants and LH2 from purple phototrophic bacteria). Proteoliposomes were self-assembled from defined mixtures of lipids, proteins and dye molecules and their optical properties were quantified by absorption and fluorescence spectroscopy. Both lipid-linked dyes and alternative lipophilic dyes were found to be effective excitation energy donors to LH protein complexes, without the need for direct chemical or generic modification of the proteins. The Förster theory parameters (e.g., spectral overlap) were compared between each donor-acceptor combination and found to be good predictors of an effective dye-protein combination. At the highest dye-to-protein ratios tested (over 20:1), the effective absorption strength integrated over the full spectral range was increased to ∼180% of its natural level for both LH complexes. Lipophilic dyes could be inserted into pre-formed membranes although their effectiveness was found to depend upon favourable physicochemical interactions. Finally, we demonstrated that these dyes can also be effective at increasing the spectral range of surface-supported models of photosynthetic membranes, using fluorescence microscopy. The results of this work provide insight into the utility of self-assembled lipid membranes and the great flexibility of LH complexes for interacting with different dyes.
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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
| | - David J K Swainsbury
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK; School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
| | - Sophie A Meredith
- 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
| | - Kenichi Morigaki
- Graduate School of Agricultural Science and Biosignal Research Center, Kobe University, Rokkodaicho 1-1, Nada, Kobe 657-8501, Japan
| | - C Neil Hunter
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - 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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6
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Yamano N, Wang P, Dong FQ, Zhang JP. Lipid-Enhanced Photoprotection of LHCII in Membrane Nanodisc by Reducing Chlorophyll Triplet Production. J Phys Chem B 2022; 126:2669-2676. [PMID: 35377647 DOI: 10.1021/acs.jpcb.1c10557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Carotenoid (Car) quenching chlorophyll triplet state (3Chl a*), an unwanted photosensitizer yielding harmful reactive oxygen species, is crucial for the survival of oxygenic photosynthetic organisms. For the major light-harvesting complex of photosystem II (LHCII) in isolated form, 3Chl a* is deactivated via sub-nanosecond Chl-to-Car triplet excitation energy transfer by lutein in the central domain of LHCII; however, the mechanistic difference from LHCII in vivo remains to be explored. To investigate the intrinsic Car-photoprotection properties of LHCII in a bio-mimicking circumstance, we reconstituted trimeric spinach LHCII into the discoidal membrane of nanosize made from l-α-phosphatidylcholine and examined the triplet excited dynamics. Time-resolved optical absorption combined with circular dichroism spectroscopies revealed that, with reference to LHCII in buffer, LHCII in the membrane nanodisc shows appreciable conformational variation in the neoxanthin and the Lut621 domains and in the Chl a-terminal cluster owing to the lipid-protein interactions, which, in turn, alters the triplet population of Lut620 and Lut621 and their partition. Importantly, the unquenched 3Chl a* population in the complex was reduced by 60%, indicating that LHCII in the membrane adopts a conformation that is optimized for the alleviation of photoinhibition.
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Affiliation(s)
- Nami Yamano
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing, 100872 Beijing, China
| | - Peng Wang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing, 100872 Beijing, China
| | - Feng-Qin Dong
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Jian-Ping Zhang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing, 100872 Beijing, China
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7
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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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8
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Manna P, Davies T, Hoffmann M, Johnson MP, Schlau-Cohen GS. Membrane-dependent heterogeneity of LHCII characterized using single-molecule spectroscopy. Biophys J 2021; 120:3091-3102. [PMID: 34214527 DOI: 10.1016/j.bpj.2021.06.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/16/2021] [Accepted: 06/08/2021] [Indexed: 10/21/2022] Open
Abstract
In green plants, light harvesting complex of Photosystem II (LHCII) absorbs and transports excitation energy toward the photosynthetic reaction centers and serves as a site for energy-dependent nonphotochemical quenching (qE), the photoprotective dissipation of energy as heat. LHCII is thought to activate dissipation through conformational changes that change the photophysical behaviors. Understanding this balance requires a characterization of how the conformations of LHCII, and thus its photophysics, are influenced by individual factors within the membrane environment. Here, we used ensemble and single-molecule fluorescence to characterize the excited-state lifetimes and switching kinetics of LHCII embedded in nanodisc- and liposome-based model membranes of various sizes and lipid compositions. As the membrane area decreased, the quenched population and the rate of conformational dynamics both increased because of interactions with other proteins, the aqueous solution, and/or disordered lipids. Although the conformational states and dynamics were similar in both thylakoid and asolectin lipids, photodegradation increased with thylakoid lipids, likely because of their charge and pressure properties. Collectively, these findings demonstrate the ability of membrane environments to tune the conformations and photophysics of LHCII.
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Affiliation(s)
- Premashis Manna
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Thomas Davies
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Madeline Hoffmann
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
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9
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Shukla MK, Watanabe A, Wilson S, Giovagnetti V, Moustafa EI, Minagawa J, Ruban AV. A novel method produces native light-harvesting complex II aggregates from the photosynthetic membrane revealing their role in nonphotochemical quenching. J Biol Chem 2021; 295:17816-17826. [PMID: 33454016 DOI: 10.1074/jbc.ra120.016181] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/15/2020] [Indexed: 01/31/2023] Open
Abstract
Nonphotochemical quenching (NPQ) is a mechanism of regulating light harvesting that protects the photosynthetic apparatus from photodamage by dissipating excess absorbed excitation energy as heat. In higher plants, the major light-harvesting antenna complex (LHCII) of photosystem (PS) II is directly involved in NPQ. The aggregation of LHCII is proposed to be involved in quenching. However, the lack of success in isolating native LHCII aggregates has limited the direct interrogation of this process. The isolation of LHCII in its native state from thylakoid membranes has been problematic because of the use of detergent, which tends to dissociate loosely bound proteins, and the abundance of pigment-protein complexes (e.g. PSI and PSII) embedded in the photosynthetic membrane, which hinders the preparation of aggregated LHCII. Here, we used a novel purification method employing detergent and amphipols to entrap LHCII in its natural states. To enrich the photosynthetic membrane with the major LHCII, we used Arabidopsis thaliana plants lacking the PSII minor antenna complexes (NoM), treated with lincomycin to inhibit the synthesis of PSI and PSII core proteins. Using sucrose density gradients, we succeeded in isolating the trimeric and aggregated forms of LHCII antenna. Violaxanthin- and zeaxanthin-enriched complexes were investigated in dark-adapted, NPQ, and dark recovery states. Zeaxanthin-enriched antenna complexes showed the greatest amount of aggregated LHCII. Notably, the amount of aggregated LHCII decreased upon relaxation of NPQ. Employing this novel preparative method, we obtained a direct evidence for the role of in vivo LHCII aggregation in NPQ.
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Affiliation(s)
- Mahendra K Shukla
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Akimasa Watanabe
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Japan; Department of Basic Biology, School of Life Science, SOKENDAI, The Graduate University for Advanced Studies, Okazaki, Japan
| | - Sam Wilson
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Vasco Giovagnetti
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Ece Imam Moustafa
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology, Okazaki, Japan; Department of Basic Biology, School of Life Science, SOKENDAI, The Graduate University for Advanced Studies, Okazaki, Japan.
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.
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10
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Aggregation-related quenching of LHCII fluorescence in liposomes revealed by single-molecule spectroscopy. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2021; 218:112174. [PMID: 33799009 DOI: 10.1016/j.jphotobiol.2021.112174] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/04/2021] [Accepted: 03/21/2021] [Indexed: 11/20/2022]
Abstract
Incorporation of membrane proteins into reconstituted lipid membranes is a common approach for studying their structure and function relationship in a native-like environment. In this work, we investigated fluorescence properties of liposome-reconstituted major light-harvesting complexes of plants (LHCII). By utilizing liposome labelling with the fluorescent dye molecules and single-molecule microscopy techniques, we were able to study truly liposome-reconstituted LHCII and compare them with bulk measurements and liposome-free LHCII aggregates bound to the surface. Our results showed that fluorescence lifetime obtained in bulk and in single liposome measurements were correlated. The fluorescence lifetimes of LHCII were shorter for liposome-free LHCII than for reconstituted LHCII. In the case of liposome-reconstituted LHCII, fluorescence lifetime showed dependence on the protein density reminiscent to concentration quenching. The dependence of fluorescence lifetime of LHCII on the liposome size was not significant. Our results demonstrated that fluorescence quenching can be induced by LHCII - LHCII interactions in reconstituted membranes, most likely occurring via the same mechanism as photoprotective non-photochemical quenching in vivo.
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11
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Artes Vivancos JM, van Stokkum IHM, Saccon F, Hontani Y, Kloz M, Ruban A, van Grondelle R, Kennis JTM. Unraveling the Excited-State Dynamics and Light-Harvesting Functions of Xanthophylls in Light-Harvesting Complex II Using Femtosecond Stimulated Raman Spectroscopy. J Am Chem Soc 2020; 142:17346-17355. [PMID: 32878439 PMCID: PMC7564077 DOI: 10.1021/jacs.0c04619] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
![]()
Photosynthesis
in plants starts with the capture of photons by
light-harvesting complexes (LHCs). Structural biology and spectroscopy
approaches have led to a map of the architecture and energy transfer
pathways between LHC pigments. Still, controversies remain regarding
the role of specific carotenoids in light-harvesting and photoprotection,
obligating the need for high-resolution techniques capable of identifying
excited-state signatures and molecular identities of the various pigments
in photosynthetic systems. Here we demonstrate the successful application
of femtosecond stimulated Raman spectroscopy (FSRS) to a multichromophoric
biological complex, trimers of LHCII. We demonstrate the application
of global and target analysis (GTA) to FSRS data and utilize it to
quantify excitation migration in LHCII trimers. This powerful combination
of techniques allows us to obtain valuable insights into structural,
electronic, and dynamic information from the carotenoids of LHCII
trimers. We report spectral and dynamical information on ground- and
excited-state vibrational modes of the different pigments, resolving
the vibrational relaxation of the carotenoids and the pathways of
energy transfer to chlorophylls. The lifetimes and spectral characteristics
obtained for the S1 state confirm that lutein 2 has a distorted conformation
in LHCII and that the lutein 2 S1 state does not transfer to chlorophylls,
while lutein 1 is the only carotenoid whose S1 state plays a significant
energy-harvesting role. No appreciable energy transfer takes place
from lutein 1 to lutein 2, contradicting recent proposals regarding
the functions of the various carotenoids (Son et al. Chem.2019, 5 (3), 575–584). Also, our results demonstrate that FSRS can be used in combination
with GTA to simultaneously study the electronic and vibrational landscapes
in LHCs and pave the way for in-depth studies of photoprotective conformations
in photosynthetic systems.
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Affiliation(s)
- Juan M Artes Vivancos
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.,Department of Chemistry, Kennedy College of Science, University of Massachusetts-Lowell, One University Avenue, Lowell, Massachusetts 01854, United States
| | - Ivo H M van Stokkum
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Francesco Saccon
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road/E1 4NS London, U.K
| | - Yusaku Hontani
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Miroslav Kloz
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Alexander Ruban
- Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road/E1 4NS London, U.K
| | - Rienk van Grondelle
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - John T M Kennis
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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12
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Son M, Pinnola A, Schlau-Cohen GS. Zeaxanthin independence of photophysics in light-harvesting complex II in a membrane environment. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148115. [DOI: 10.1016/j.bbabio.2019.148115] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 10/21/2019] [Accepted: 11/08/2019] [Indexed: 11/15/2022]
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13
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Danmaliki GI, Hwang PM. Solution NMR spectroscopy of membrane proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183356. [PMID: 32416193 DOI: 10.1016/j.bbamem.2020.183356] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 02/06/2023]
Abstract
Integral membrane proteins (IMPs) perform unique and indispensable functions in the cell, making them attractive targets for fundamental research and drug discovery. Developments in protein production, isotope labeling, sample preparation, and pulse sequences have extended the utility of solution NMR spectroscopy for studying IMPs with multiple transmembrane segments. Here we review some recent applications of solution NMR for studying structure, dynamics, and interactions of polytopic IMPs, emphasizing strategies used to overcome common technical challenges.
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Affiliation(s)
- Gaddafi I Danmaliki
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Peter M Hwang
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada; Department of Medicine, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
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14
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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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15
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Ganapathy S, Opdam L, Hontani Y, Frehan S, Chen Q, Hellingwerf KJ, de Groot HJ, Kennis JT, de Grip WJ. Membrane matters: The impact of a nanodisc-bilayer or a detergent microenvironment on the properties of two eubacterial rhodopsins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183113. [DOI: 10.1016/j.bbamem.2019.183113] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/20/2019] [Accepted: 10/22/2019] [Indexed: 12/29/2022]
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16
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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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17
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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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18
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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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19
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Akhtar P, Görföl F, Garab G, Lambrev PH. Dependence of chlorophyll fluorescence quenching on the lipid-to-protein ratio in reconstituted light-harvesting complex II membranes containing lipid labels. Chem Phys 2019. [DOI: 10.1016/j.chemphys.2019.03.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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20
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Vargas C, Schönbeck C, Heimann I, Keller S. Extracavity Effect in Cyclodextrin/Surfactant Complexation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:5781-5787. [PMID: 29683671 DOI: 10.1021/acs.langmuir.8b00682] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cyclodextrin (CD) complexation is a convenient method to sequester surfactants in a controllable way, for example, during membrane-protein reconstitution. Interestingly, the equilibrium stability of CD/surfactant inclusion complexes increases with the length of the nonpolar surfactant chain even beyond the point where all hydrophobic contacts within the canonical CD cavity are saturated. To rationalize this observation, we have dissected the inclusion complexation equilibria of a structurally well-defined CD, that is, heptakis(2,6-di- O-methyl)-β-CD (DIMEB), and a homologous series of surfactants, namely, n-alkyl- N, N-dimethyl-3-ammonio-1-propanesulfonates (SB3- x) with chain lengths ranging from x = 8 to 14. Thermodynamic parameters obtained by isothermal titration calorimetry and structural insights derived from nuclear magnetic resonance spectroscopy and molecular dynamics simulations revealed that, upon inclusion, long-chain surfactants with x = ≥10 extend beyond the canonical CD cavity. This enables the formation of hydrophobic contacts between long surfactant chains and the extracavity parts of DIMEB, which make additional favorable contributions to the stability of the inclusion complex. These results explain the finding that the stability of CD/surfactant inclusion complexes monotonously increases with the surfactant chain length even for long chains that completely fill the canonical CD cavity.
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Affiliation(s)
- Carolyn Vargas
- Molecular Biophysics , Technische Universität Kaiserslautern (TUK) , Erwin-Schrödinger-Str. 13 , 67663 Kaiserslautern , Germany
| | - Christian Schönbeck
- Department of Science and Environment , Roskilde University , Universitetsvej 1 , 4000 Roskilde , Denmark
| | - Ina Heimann
- Molecular Biophysics , Technische Universität Kaiserslautern (TUK) , Erwin-Schrödinger-Str. 13 , 67663 Kaiserslautern , Germany
| | - Sandro Keller
- Molecular Biophysics , Technische Universität Kaiserslautern (TUK) , Erwin-Schrödinger-Str. 13 , 67663 Kaiserslautern , Germany
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21
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Ogren JI, Tong AL, Gordon SC, Chenu A, Lu Y, Blankenship RE, Cao J, Schlau-Cohen GS. Impact of the lipid bilayer on energy transfer kinetics in the photosynthetic protein LH2. Chem Sci 2018; 9:3095-3104. [PMID: 29732092 PMCID: PMC5914429 DOI: 10.1039/c7sc04814a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 02/05/2018] [Indexed: 01/28/2023] Open
Abstract
Photosynthetic purple bacteria convert solar energy to chemical energy with near unity quantum efficiency. The light-harvesting process begins with absorption of solar energy by an antenna protein called Light-Harvesting Complex 2 (LH2). Energy is subsequently transferred within LH2 and then through a network of additional light-harvesting proteins to a central location, termed the reaction center, where charge separation occurs. The energy transfer dynamics of LH2 are highly sensitive to intermolecular distances and relative organizations. As a result, minor structural perturbations can cause significant changes in these dynamics. Previous experiments have primarily been performed in two ways. One uses non-native samples where LH2 is solubilized in detergent, which can alter protein structure. The other uses complex membranes that contain multiple proteins within a large lipid area, which make it difficult to identify and distinguish perturbations caused by protein-protein interactions and lipid-protein interactions. Here, we introduce the use of the biochemical platform of model membrane discs to study the energy transfer dynamics of photosynthetic light-harvesting complexes in a near-native environment. We incorporate a single LH2 from Rhodobacter sphaeroides into membrane discs that provide a spectroscopically amenable sample in an environment more physiological than detergent but less complex than traditional membranes. This provides a simplified system to understand an individual protein and how the lipid-protein interaction affects energy transfer dynamics. We compare the energy transfer rates of detergent-solubilized LH2 with those of LH2 in membrane discs using transient absorption spectroscopy and transient absorption anisotropy. For one key energy transfer step in LH2, we observe a 30% enhancement of the rate for LH2 in membrane discs compared to that in detergent. Based on experimental results and theoretical modeling, we attribute this difference to tilting of the peripheral bacteriochlorophyll in the B800 band. These results highlight the importance of well-defined systems with near-native membrane conditions for physiologically-relevant measurements.
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Affiliation(s)
- John I Ogren
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA 02139 , USA .
| | - Ashley L Tong
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA 02139 , USA .
| | - Samuel C Gordon
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA 02139 , USA .
| | - Aurélia Chenu
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA 02139 , USA .
| | - Yue Lu
- Department of Biology and Chemistry , Washington University in St. Louis , St. Louis , MO 63130 , USA
| | - Robert E Blankenship
- Department of Biology and Chemistry , Washington University in St. Louis , St. Louis , MO 63130 , USA
| | - Jianshu Cao
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA 02139 , USA .
| | - Gabriela S Schlau-Cohen
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA 02139 , USA .
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22
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Faas R, Kiefer D, Job L, Pohle A, Moß K, Henkel M, Hausmann R. Time-course and degradation rate of membrane scaffold protein (MSP1D1) during recombinant production. ACTA ACUST UNITED AC 2018; 17:45-48. [PMID: 29379767 PMCID: PMC5773449 DOI: 10.1016/j.btre.2017.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 11/24/2017] [Accepted: 12/13/2017] [Indexed: 11/15/2022]
Abstract
Relevant efficiency parameters, productivities and production rates for recombinant MSP1D1 are presented for the first time. Time-course of MSP1D1 concentration was quantified post-induction in comparison to a reference protein. Calculation of specific production rates confirm that degradation is the reason for decreased yields during MSP1D1 expression.
Membrane scaffold proteins (MSPs) are synthetic derivatives of apolipoprotein A-I, a major protein component of human high-density lipoprotein complexes. The most common among these is the variant MSP1D1, which has been in the focus of research on membrane mimetics in the past. As such, the amphipathic MSP1D1 has the ability to self-assemble in the presence of synthetic phospholipids into discoidal nanoparticles, so called nanodiscs. The recombinant production of MSP is exclusively reported using a standard laboratory expression system of the pET family. However, strong variations in both yield and achieved concentration as well as complications related to unspecific degradation are commonly reported. In addition, the time-course of recombinant protein as well as specific protein yields have not yet been quantified conclusively. In this study, the time-course of MSP1D1 concentration was investigated in a standard pET expression system in terms of quantification of production and degradation rates in comparison to a reference protein (eGFP).
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Affiliation(s)
- Ramona Faas
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
| | - Dirk Kiefer
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
| | - Laura Job
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
| | - Annelie Pohle
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
| | - Karin Moß
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
| | - Marius Henkel
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
| | - Rudolf Hausmann
- Institute of Food Science and Biotechnology (150), Department of Bioprocess Engineering (150k), University of Hohenheim, Fruwirthstraße 12, 70599, Stuttgart, Germany
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23
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Hall SCL, Tognoloni C, Price GJ, Klumperman B, Edler KJ, Dafforn TR, Arnold T. Influence of Poly(styrene-co-maleic acid) Copolymer Structure on the Properties and Self-Assembly of SMALP Nanodiscs. Biomacromolecules 2017; 19:761-772. [DOI: 10.1021/acs.biomac.7b01539] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stephen C. L. Hall
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
| | - Cecilia Tognoloni
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
- ISIS Neutron and Muon Source, Science and Technology Facilities Council Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX, United Kingdom
| | - Gareth J. Price
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Bert Klumperman
- Department of Chemistry and Polymer Science, Division of Polymer Science, Stellenbosch University, De Beers Street, Stellenbosch 7600, South Africa
| | - Karen J. Edler
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Tim R. Dafforn
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Thomas Arnold
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, United Kingdom
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24
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Seiwert D, Witt H, Janshoff A, Paulsen H. The non-bilayer lipid MGDG stabilizes the major light-harvesting complex (LHCII) against unfolding. Sci Rep 2017; 7:5158. [PMID: 28698661 PMCID: PMC5505961 DOI: 10.1038/s41598-017-05328-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 06/07/2017] [Indexed: 01/03/2023] Open
Abstract
In the photosynthetic apparatus of plants a high proportion of LHCII protein is needed to integrate 50% non-bilayer lipid MGDG into the lamellar thylakoid membrane, but whether and how the stability of the protein is also affected is not known. Here we use single-molecule force spectroscopy to map the stability of LHCII against mechanical unfolding along the polypeptide chain as a function of oligomerization state and lipid composition. Comparing unfolding forces between monomeric and trimeric LHCII demonstrates that the stability does not increase significantly upon trimerization but can mainly be correlated with specific contact sites between adjacent monomers. In contrast, unfolding of trimeric complexes in membranes composed of different thylakoid lipids reveals that the non-bilayer lipid MGDG substantially increases the mechanical stability of LHCII in many segments of the protein compared to other lipids such as DGDG or POPG. We attribute these findings to steric matching of conically formed MGDG and the hourglass shape of trimeric LHCII, thereby extending the role of non-bilayer lipids to the structural stabilization of membrane proteins in addition to the modulation of their folding, conformation and function.
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Affiliation(s)
- Dennis Seiwert
- Institute of Molecular Physiology, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Hannes Witt
- Institute of Physical Chemistry, University of Goettingen, 37077, Göttingen, Germany
| | - Andreas Janshoff
- Institute of Physical Chemistry, University of Goettingen, 37077, Göttingen, Germany.
| | - Harald Paulsen
- Institute of Molecular Physiology, Johannes Gutenberg University Mainz, 55128, Mainz, Germany.
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25
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Rouck J, Krapf J, Roy J, Huff H, Das A. Recent advances in nanodisc technology for membrane protein studies (2012-2017). FEBS Lett 2017; 591:2057-2088. [PMID: 28581067 PMCID: PMC5751705 DOI: 10.1002/1873-3468.12706] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 05/26/2017] [Accepted: 05/31/2017] [Indexed: 01/01/2023]
Abstract
Historically, the main barrier to membrane protein investigations has been the tendency of membrane proteins to aggregate (due to their hydrophobic nature), in aqueous solution as well as on surfaces. The introduction of biomembrane mimetics has since stimulated momentum in the field. One such mimetic, the nanodisc (ND) system, has proved to be an exceptional system for solubilizing membrane proteins. Herein, we critically evaluate the advantages and imperfections of employing nanodiscs in biophysical and biochemical studies. Specifically, we examine the techniques that have been modified to study membrane proteins in nanodiscs. Techniques discussed here include fluorescence microscopy, solution-state/solid-state nuclear magnetic resonance, electron microscopy, small-angle X-ray scattering, and several mass spectroscopy methods. Newer techniques such as SPR, charge-sensitive optical detection, and scintillation proximity assays are also reviewed. Lastly, we cover how nanodiscs are advancing nanotechnology through nanoplasmonic biosensing, lipoprotein-nanoplatelets, and sortase-mediated labeling of nanodiscs.
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Affiliation(s)
- John Rouck
- Department of Biochemistry, University of Illinois Urbana–Champaign, Urbana IL 61802, USA
| | - John Krapf
- Department of Biochemistry, University of Illinois Urbana–Champaign, Urbana IL 61802, USA
| | - Jahnabi Roy
- Department of Chemistry, University of Illinois Urbana–Champaign, Urbana IL 61802, USA
| | - Hannah Huff
- Department of Chemistry, University of Illinois Urbana–Champaign, Urbana IL 61802, USA
| | - Aditi Das
- Department of Comparative Biosciences, University of Illinois Urbana–Champaign, Urbana IL 61802, USA
- Department of Biochemistry, University of Illinois Urbana–Champaign, Urbana IL 61802, USA
- Beckman Institute for Advanced Science, Division of Nutritional Sciences, Neuroscience Program and Department of Bioengineering, University of Illinois Urbana–Champaign, Urbana IL 61802, USA
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26
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Abstract
Membrane proteins play a most important part in metabolism, signaling, cell motility, transport, development, and many other biochemical and biophysical processes which constitute fundamentals of life on the molecular level. Detailed understanding of these processes is necessary for the progress of life sciences and biomedical applications. Nanodiscs provide a new and powerful tool for a broad spectrum of biochemical and biophysical studies of membrane proteins and are commonly acknowledged as an optimal membrane mimetic system that provides control over size, composition, and specific functional modifications on the nanometer scale. In this review we attempted to combine a comprehensive list of various applications of nanodisc technology with systematic analysis of the most attractive features of this system and advantages provided by nanodiscs for structural and mechanistic studies of membrane proteins.
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Affiliation(s)
- Ilia G Denisov
- Department of Biochemistry and Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
| | - Stephen G Sligar
- Department of Biochemistry and Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States
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Disentangling protein and lipid interactions that control a molecular switch in photosynthetic light harvesting. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:40-47. [DOI: 10.1016/j.bbamem.2016.10.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Revised: 09/30/2016] [Accepted: 10/21/2016] [Indexed: 11/18/2022]
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Tuning the Photocycle Kinetics of Bacteriorhodopsin in Lipid Nanodiscs. Biophys J 2016; 109:1899-906. [PMID: 26536266 DOI: 10.1016/j.bpj.2015.09.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/19/2015] [Accepted: 09/11/2015] [Indexed: 11/22/2022] Open
Abstract
Monodisperse lipid nanodiscs are particularly suitable for characterizing membrane protein in near-native environment. To study the lipid-composition dependence of photocycle kinetics of bacteriorhodopsin (bR), transient absorption spectroscopy was utilized to monitor the evolution of the photocycle intermediates of bR reconstituted in nanodiscs composed of different ratios of the zwitterionic lipid (DMPC, dimyristoyl phosphatidylcholine; DOPC, dioleoyl phosphatidylcholine) to the negatively charged lipid (DOPG, dioleoyl phosphatidylglycerol; DMPG, dimyristoyl phosphatidylglycerol). The characterization of ion-exchange chromatography showed that the negative surface charge of nanodiscs increased as the content of DOPG or DMPG was increased. The steady-state absorption contours of the light-adapted monomeric bR in nanodiscs composed of different lipid ratios exhibited highly similar absorption features of the retinal moiety at 560 nm, referring to the conservation of the tertiary structure of bR in nanodiscs of different lipid compositions. In addition, transient absorption contours showed that the photocycle kinetics of bR was significantly retarded and the transient populations of intermediates N and O were decreased as the content of DMPG or DOPG was reduced. This observation could be attributed to the negatively charged lipid heads of DMPG and DOPG, exhibiting similar proton relay capability as the native phosphatidylglycerol (PG) analog lipids in the purple membrane. In this work, we not only demonstrated the usefulness of nanodiscs as a membrane-mimicking system, but also showed that the surrounding lipids play a crucial role in altering the biological functions, e.g., the ion translocation kinetics of the transmembrane proteins.
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Benjamin CJ, Wright KJ, Hyun SH, Krynski K, Yu G, Bajaj R, Guo F, Stauffacher CV, Jiang W, Thompson DH. Nonfouling NTA-PEG-Based TEM Grid Coatings for Selective Capture of Histidine-Tagged Protein Targets from Cell Lysates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:551-9. [PMID: 26726866 PMCID: PMC5310270 DOI: 10.1021/acs.langmuir.5b03445] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We report the preparation and performance of TEM grids bearing stabilized nonfouling lipid monolayer coatings. These films contain NTA capture ligands of controllable areal density at the distal end of a flexible poly(ethylene glycol) 2000 (PEG2000) spacer to avoid preferred orientation of surface-bound histidine-tagged (His-tag) protein targets. Langmuir-Schaefer deposition at 30 mN/m of mixed monolayers containing two novel synthetic lipids-1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[(5-amido-1-carboxypentyl)iminodiacetic acid]polyethylene glycolamide 2000) (NTA-PEG2000-DSPE) and 1,2-(tricosa-10',12'-diynoyl)-sn-glycero-3-phosphoethanolamine-N-(methoxypolyethylene glycolamide 350) (mPEG350-DTPE)-in 1:99 and 5:95 molar ratios prior to treatment with a 5 min, 254 nm light exposure was used for grid fabrication. These conditions were designed to limit nonspecific protein adsorption onto the stabilized lipid coating by favoring the formation of a mPEG350 brush layer below a flexible, mushroom conformation of NTA-PEG2000 at low surface density to enable specific immobilization and random orientation of the protein target on the EM grid. These grids were then used to capture His6-T7 bacteriophage and RplL from cell lysates, as well as purified His8-green fluorescent protein (GFP) and nanodisc solubilized maltose transporter, His6-MalFGK2. Our findings indicate that TEM grid supported, polymerized NTA lipid monolayers are capable of capturing His-tag protein targets in a manner that controls their areal densities, while efficiently blocking nonspecific adsorption and limiting film degradation, even upon prolonged detergent exposure.
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Affiliation(s)
- Christopher J Benjamin
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - Kyle J Wright
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - Seok-Hee Hyun
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - Kyle Krynski
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - Guimei Yu
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - Ruchika Bajaj
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - Fei Guo
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - Cynthia V Stauffacher
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - Wen Jiang
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
| | - David H Thompson
- Department of Chemistry and ‡Department of Biological Sciences, Purdue University , West Lafayette, Indiana 47907, United States
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Nakatani-Webster E, Hu SL, Atkins WM, Catalano CE. Assembly and characterization of gp160-nanodiscs: A new platform for biochemical characterization of HIV envelope spikes. J Virol Methods 2015; 226:15-24. [PMID: 26424619 DOI: 10.1016/j.jviromet.2015.09.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 09/21/2015] [Accepted: 09/25/2015] [Indexed: 01/12/2023]
Abstract
The human immunodeficiency virus (HIV) is the causative agent of acquired immune deficiency syndrome (AIDS) and is thus responsible for significant morbidity and mortality worldwide. Despite considerable effort, preparation of an effective vaccine for AIDS has been elusive and it has become clear that a fundamental understanding of the relevant antigenic targets on HIV is essential. The Env trimer spike is the only viral antigen present on the surface of the viral particle and it is the target of all broadly neutralizing antibodies isolated to date. Thus, a soluble, homogeneous, and well-defined preparation of Env trimers is an important first step toward biochemical and structural characterization of the antigenic spike. Phospholipid bilayer nanodiscs represent a relatively new technology that can serve as a platform for the assembly of membrane proteins into a native membrane-like environment. Here we describe the preparation and characterization of unprocessed full-length, natively glycoslyated gp160 Env proteins incorporated into nanodiscs (gp160-ND). The particles are soluble and well defined in the absence of detergent, and possess a morphology anticipated of Env incorporated into a lipid ND. Importantly, the gp160-NDs retain CD4 and Env antibody binding characteristics expected of a functional trimer spike and their incorporation into a lipid membrane allows interrogation of epitopes associated with the membrane-proximal ectodomain region of gp41. These studies provide the groundwork for the use of gp160-ND in more detailed biochemical and structural studies that may set the stage for their use in vaccine development.
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Affiliation(s)
- Eri Nakatani-Webster
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, H-172 Health Sciences Building, Box 357610, Seattle, WA 98195, United States
| | - Shiu-Lok Hu
- Department of Pharmaceutics, School of Pharmacy, University of Washington, H272 Health Sciences Building, Box 357610, Seattle, WA 98195, United States
| | - William M Atkins
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, H-172 Health Sciences Building, Box 357610, Seattle, WA 98195, United States
| | - Carlos Enrique Catalano
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, H-172 Health Sciences Building, Box 357610, Seattle, WA 98195, United States.
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31
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Amphipols and Photosynthetic Light-Harvesting Pigment-Protein Complexes. J Membr Biol 2014; 247:1031-41. [DOI: 10.1007/s00232-014-9712-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 07/23/2014] [Indexed: 10/24/2022]
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32
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Johnson PJM, Halpin A, Morizumi T, Brown LS, Prokhorenko VI, Ernst OP, Dwayne Miller RJ. The photocycle and ultrafast vibrational dynamics of bacteriorhodopsin in lipid nanodiscs. Phys Chem Chem Phys 2014; 16:21310-20. [PMID: 25178090 DOI: 10.1039/c4cp01826e] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photocycle and vibrational dynamics of bacteriorhodopsin in a lipid nanodisc microenvironment have been studied by steady-state and time-resolved spectroscopies. Linear absorption and circular dichroism indicate that the nanodiscs do not perturb the structure of the retinal binding pocket, while transient absorption and flash photolysis measurements show that the photocycle which underlies proton pumping is unchanged from that in the native purple membranes. Vibrational dynamics during the initial photointermediate formation are subsequently studied by ultrafast broadband transient absorption spectroscopy, where the low scattering afforded by the lipid nanodisc microenvironment allows for unambiguous assignment of ground and excited state nuclear dynamics through Fourier filtering of frequency regions of interest and subsequent time domain analysis of the retrieved vibrational dynamics. Canonical ground state oscillations corresponding to high frequency ethylenic and C-C stretches, methyl rocks, and hydrogen out-of-plane wags are retrieved, while large amplitude, short dephasing time vibrations are recovered predominantly in the frequency region associated with out-of-plane dynamics and low frequency torsional modes implicated in isomerization.
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Affiliation(s)
- Philip J M Johnson
- Institute for Optical Sciences & Departments of Chemistry & Physics, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
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33
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Marty MT, Wilcox KC, Klein WL, Sligar SG. Nanodisc-solubilized membrane protein library reflects the membrane proteome. Anal Bioanal Chem 2013; 405:4009-16. [PMID: 23400332 PMCID: PMC3628400 DOI: 10.1007/s00216-013-6790-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 01/18/2013] [Accepted: 01/24/2013] [Indexed: 11/28/2022]
Abstract
The isolation and identification of unknown membrane proteins offers the prospect of discovering new pharmaceutical targets and identifying key biochemical receptors. However, interactions between membrane protein targets and soluble ligands are difficult to study in vitro due to the insolubility of membrane proteins in non-detergent systems. Nanodiscs, nanoscale discoidal lipid bilayers encircled by a membrane scaffold protein belt, have proven to be an effective platform to solubilize membrane proteins and have been used to study a wide variety of purified membrane proteins. This report details the incorporation of an unbiased population of membrane proteins from Escherichia coli membranes into Nanodiscs. This solubilized membrane protein library (SMPL) forms a soluble in vitro model of the membrane proteome. Since Nanodiscs contain isolated proteins or small complexes, the SMPL is an ideal platform for interactomics studies and pull-down assays of membrane proteins. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the protein population before and after formation of the Nanodisc library indicates that a large percentage of the proteins are incorporated into the library. Proteomic identification of several prominent bands demonstrates the successful incorporation of outer and inner membrane proteins into the Nanodisc library.
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Affiliation(s)
- Michael T. Marty
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Kyle C. Wilcox
- Department of Neurobiology, Northwestern University, Evanston, IL 60208; USA
| | - William L. Klein
- Department of Neurobiology, Northwestern University, Evanston, IL 60208; USA
| | - Stephen G. Sligar
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
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34
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Sunku K, de Groot HJM, Pandit A. Insights into the photoprotective switch of the major light-harvesting complex II (LHCII): a preserved core of arginine-glutamate interlocked helices complemented by adjustable loops. J Biol Chem 2013; 288:19796-804. [PMID: 23629658 DOI: 10.1074/jbc.m113.456111] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Light-harvesting antennae of the LHC family form transmembrane three-helix bundles of which two helices are interlocked by conserved arginine-glutamate (Arg-Glu) ion pairs that form ligation sites for chlorophylls. The antenna proteins of photosystem II have an intriguing dual function. In excess light, they can switch their conformation from a light-harvesting into a photoprotective state, in which the excess and harmful excitation energies are safely dissipated as heat. Here we applied magic angle spinning NMR and selective Arg isotope enrichment as a noninvasive method to analyze the Arg structures of the major light-harvesting complex II (LHCII). The conformations of the Arg residues that interlock helix A and B appear to be preserved in the light-harvesting and photoprotective state. Several Arg residues have very downfield-shifted proton NMR responses, indicating that they stabilize the complex by strong hydrogen bonds. For the Arg Cα chemical shifts, differences are observed between LHCII in the active, light-harvesting and in the photoprotective, quenched state. These differences are attributed to a conformational change of the Arg residue in the stromal loop region. We conclude that the interlocked helices of LHCII form a rigid core. Consequently, the LHCII conformational switch does not involve changes in A/B helix tilting but likely involves rearrangements of the loops and helical segments close to the stromal and lumenal ends.
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Affiliation(s)
- Kiran Sunku
- Department of Solid-State NMR, Leiden Institute of Chemistry, Gorlaeus Laboratory, Leiden University, Einsteinweg 55, 2300 RA Leiden, The Netherlands
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35
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36
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Pandit A, Reus M, Morosinotto T, Bassi R, Holzwarth AR, de Groot HJM. An NMR comparison of the light-harvesting complex II (LHCII) in active and photoprotective states reveals subtle changes in the chlorophyll a ground-state electronic structures. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:738-44. [PMID: 23466337 DOI: 10.1016/j.bbabio.2013.02.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 02/14/2013] [Accepted: 02/23/2013] [Indexed: 11/15/2022]
Abstract
To protect the photosynthetic apparatus against photo-damage in high sunlight, the photosynthetic antenna of oxygenic organisms can switch from a light-harvesting to a photoprotective mode through the process of non-photochemical quenching (NPQ). There is growing evidence that light-harvesting proteins of photosystem II participate in photoprotection by a built-in capacity to switch their conformation between light-harvesting and energy-dissipating states. Here we applied high-resolution Magic-Angle Spinning Nuclear Magnetic Resonance on uniformly (13)C-enriched major light-harvesting complex II (LHCII) of Chlamydomonas reinhardtii in active or quenched states. Our results reveal that the switch into a dissipative state is accompanied by subtle changes in the chlorophyll (Chl) a ground-state electronic structures that affect their NMR responses, particularly for the macrocycle (13)C4, (13)C5 and (13)C6 carbon atoms. Inspection of the LHCII X-ray structures shows that of the Chl molecules in the terminal emitter domain, where excited-state energy accumulates prior to further transfer or dissipation, the C4, 5 and 6 atoms are in closest proximity to lutein; supporting quenching mechanisms that involve altered Chl-lutein interactions in the dissipative state. In addition the observed changes could represent altered interactions between Chla and neoxanthin, which alters its configuration under NPQ conditions. The Chls appear to have increased dynamics in unquenched, detergent-solubilized LHCII. Our work demonstrates that solid-state Nuclear Magnetic Resonance is applicable to investigate high-resolution structural details of light-harvesting proteins in varied functional conditions, and represents a valuable tool to address their molecular plasticity associated with photoprotection.
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Affiliation(s)
- Anjali Pandit
- Department of Physics and Astronomy, VU University Amsterdam, Amsterdam, The Netherlands.
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Akkaladevi N, Hinton-Chollet L, Katayama H, Mitchell J, Szerszen L, Mukherjee S, Gogol EP, Pentelute BL, Collier RJ, Fisher MT. Assembly of anthrax toxin pore: lethal-factor complexes into lipid nanodiscs. Protein Sci 2013; 22:492-501. [PMID: 23389868 DOI: 10.1002/pro.2231] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 01/28/2013] [Indexed: 11/10/2022]
Abstract
We have devised a procedure to incorporate the anthrax protective antigen (PA) pore complexed with the N-terminal domain of anthrax lethal factor (LFN ) into lipid nanodiscs and analyzed the resulting complexes by negative-stain electron microscopy. Insertion into nanodiscs was performed without relying on primary and secondary detergent screens. The preparations were relatively pure, and the percentage of PA pore inserted into nanodiscs on EM grids was high (∼43%). Three-dimensional analysis of negatively stained single particles revealed the LFN -PA nanodisc complex mirroring the previous unliganded PA pore nanodisc structure, but with additional protein density consistent with multiple bound LFN molecules on the PA cap region. The assembly procedure will facilitate collection of higher resolution cryo-EM LFN -PA nanodisc structures and use of advanced automated particle selection methods.
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Affiliation(s)
- N Akkaladevi
- Department of Biochemistry, University of Kansas Medical Center, Kansas City, Kansas, USA
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38
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Shadiac N, Nagarajan Y, Waters S, Hrmova M. Close allies in membrane protein research: Cell-free synthesis and nanotechnology. Mol Membr Biol 2013; 30:229-45. [DOI: 10.3109/09687688.2012.762125] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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39
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Luthra A, Gregory M, Grinkova YV, Denisov IG, Sligar SG. Nanodiscs in the studies of membrane-bound cytochrome P450 enzymes. Methods Mol Biol 2013; 987:115-27. [PMID: 23475672 DOI: 10.1007/978-1-62703-321-3_10] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cytochromes P450 from eukaryotes and their native redox partners cytochrome P450 reductases both belong to the class of monotopic membrane proteins containing one transmembrane anchor. Incorporation into the lipid bilayer significantly affects their equilibrium and kinetic properties and plays an important role in their interactions. We describe here the detailed protocols developed in our group for the functional self-assembly of mammalian cytochromes P450 and cytochrome P450 reductases into Nanodiscs with controlled lipid composition. The resulting preparations are fully functional, homogeneous in size, composition and oligomerization state of the heme enzyme, and show an improved stability with respect to P420 formation. We provide a brief overview of applications of Nanodisc technology to the biophysical and biochemical mechanistic studies of cytochromes P450 involved in steroidogenesis, and of the most abundant xenobiotic-metabolizing human cytochrome P450 CYP3A4.
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Affiliation(s)
- A Luthra
- Department of Biochemistry, University of Illinois, Urbana, IL, USA
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Belgio E, Johnson M, Jurić S, Ruban A. Higher plant photosystem II light-harvesting antenna, not the reaction center, determines the excited-state lifetime-both the maximum and the nonphotochemically quenched. Biophys J 2012; 102:2761-71. [PMID: 22735526 PMCID: PMC3379028 DOI: 10.1016/j.bpj.2012.05.004] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 05/02/2012] [Accepted: 05/07/2012] [Indexed: 11/28/2022] Open
Abstract
The maximum chlorophyll fluorescence lifetime in isolated photosystem II (PSII) light-harvesting complex (LHCII) antenna is 4 ns; however, it is quenched to 2 ns in intact thylakoid membranes when PSII reaction centers (RCIIs) are closed (Fm). It has been proposed that the closed state of RCIIs is responsible for the quenching. We investigated this proposal using a new, to our knowledge, model system in which the concentration of RCIIs was highly reduced within the thylakoid membrane. The system was developed in Arabidopsis thaliana plants under long-term treatment with lincomycin, a chloroplast protein synthesis inhibitor. The treatment led to 1), a decreased concentration of RCIIs to 10% of the control level and, interestingly, an increased antenna component; 2), an average reduction in the yield of photochemistry to 0.2; and 3), an increased nonphotochemical chlorophyll fluorescence quenching (NPQ). Despite these changes, the average fluorescence lifetimes measured in Fm and Fm' (with NPQ) states were nearly identical to those obtained from the control. A 77 K fluorescence spectrum analysis of treated PSII membranes showed the typical features of preaggregation of LHCII, indicating that the state of LHCII antenna in the dark-adapted photosynthetic membrane is sufficient to determine the 2 ns Fm lifetime. Therefore, we conclude that the closed RCs do not cause quenching of excitation in the PSII antenna, and play no role in the formation of NPQ.
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Affiliation(s)
- Erica Belgio
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Matthew P. Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Snježana Jurić
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Alexander V. Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
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