1
|
Likkei K, Moldenhauer M, Tavraz NN, Egorkin NA, Slonimskiy YB, Maksimov EG, Sluchanko NN, Friedrich T. Elements of the C-terminal tail of a C-terminal domain homolog of the Orange Carotenoid Protein determining xanthophyll uptake from liposomes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149043. [PMID: 38522658 DOI: 10.1016/j.bbabio.2024.149043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/07/2024] [Accepted: 03/09/2024] [Indexed: 03/26/2024]
Abstract
Carotenoids perform multifaceted roles in life ranging from coloration over light harvesting to photoprotection. The Orange Carotenoid Protein (OCP), a light-driven photoswitch involved in cyanobacterial photoprotection, accommodates a ketocarotenoid vital for its function. OCP extracts its ketocarotenoid directly from membranes, or accepts it from homologs of its C-terminal domain (CTDH). The CTDH from Anabaena (AnaCTDH) was shown to be important for carotenoid transfer and delivery from/to membranes. The C-terminal tail of AnaCTDH is a critical structural element likely serving as a gatekeeper and facilitator of carotenoid uptake from membranes. We investigated the impact of amino acid substitutions within the AnaCTDH-CTT on echinenone and canthaxanthin uptake from DOPC and DMPG liposomes. The transfer rate was uniformly reduced for substitutions of Arg-137 and Arg-138 to Gln or Ala, and depended on the lipid type, indicating a weaker interaction particularly with the lipid head group. Our results further suggest that Glu-132 has a membrane-anchoring effect on the PC lipids, specifically at the choline motif as inferred from the strongly different effects of the CTT variants on the extraction from the two liposome types. The substitution of Pro-130 by Gly suggests that the CTT is perpendicular to both the membrane and the main AnaCTDH protein during carotenoid extraction. Finally, the simultaneous mutation of Leu-133, Leu-134 and Leu-136 for alanines showed that the hydrophobicity of the CTT is crucial for carotenoid uptake. Since some substitutions accelerated carotenoid transfer into AnaCTDH while others slowed it down, carotenoprotein properties can be engineered toward the requirements of applications.
Collapse
Affiliation(s)
- Kristina Likkei
- Technische Universität Berlin, Institute of Chemistry, PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Marcus Moldenhauer
- Technische Universität Berlin, Institute of Chemistry, PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Neslihan N Tavraz
- Technische Universität Berlin, Institute of Chemistry, PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Nikita A Egorkin
- Federal Research Center of Biotechnology of the Russian Academy of Sciences, A.N. Bach Institute of Biochemistry, Leninsky Prospect 33-1, Moscow 119071, Russian Federation; Lomonosov Moscow State University, Faculty of Biology, Leninskie Gory 1-12, Moscow 119991, Russian Federation
| | - Yury B Slonimskiy
- Federal Research Center of Biotechnology of the Russian Academy of Sciences, A.N. Bach Institute of Biochemistry, Leninsky Prospect 33-1, Moscow 119071, Russian Federation
| | - Eugene G Maksimov
- Lomonosov Moscow State University, Faculty of Biology, Leninskie Gory 1-12, Moscow 119991, Russian Federation
| | - Nikolai N Sluchanko
- Federal Research Center of Biotechnology of the Russian Academy of Sciences, A.N. Bach Institute of Biochemistry, Leninsky Prospect 33-1, Moscow 119071, Russian Federation
| | - Thomas Friedrich
- Technische Universität Berlin, Institute of Chemistry, PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany.
| |
Collapse
|
2
|
Elanskaya IV, Bulychev AA, Lukashev EP, Muronets EM, Maksimov EG. Roles of ApcD and orange carotenoid protein in photoinduction of electron transport upon dark-light transition in the Synechocystis PCC 6803 mutant deficient in flavodiiron protein Flv1. PHOTOSYNTHESIS RESEARCH 2024; 159:97-114. [PMID: 37093504 DOI: 10.1007/s11120-023-01019-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 04/13/2023] [Indexed: 05/03/2023]
Abstract
Flavodiiron proteins Flv1/Flv3 accept electrons from photosystem (PS) I. In this work we investigated light adaptation mechanisms of Flv1-deficient mutant of Synechocystis PCC 6803, incapable to form the Flv1/Flv3 heterodimer. First seconds of dark-light transition were studied by parallel measurements of light-induced changes in chlorophyll fluorescence, P700 redox transformations, fluorescence emission at 77 K, and OCP-dependent fluorescence quenching. During the period of Calvin cycle activation upon dark-light transition, the linear electron transport (LET) in wild type is supported by the Flv1/Flv3 heterodimer, whereas in Δflv1 mutant activation of LET upon illumination is preceded by cyclic electron flow that maintains State 2. The State 2-State 1 transition and Orange Carotenoid Protein (OCP)-dependent non-photochemical quenching occur independently of each other, begin in about 10 s after the illumination of the cells and are accompanied by a short-term re-reduction of the PSI reaction center (P700+). ApcD is important for the State 2-State 1 transition in the Δflv1 mutant, but S-M rise in chlorophyll fluorescence was not completely inhibited in Δflv1/ΔapcD mutant. LET in Δflv1 mutant starts earlier than the S-M rise in chlorophyll fluorescence, and the oxidation of plastoquinol (PQH2) pool promotes the activation of PSII, transient re-reduction of P700+ and transition to State 1. An attempt to induce state transition in the wild type under high intensity light using methyl viologen, highly oxidizing P700 and PQH2, was unsuccessful, showing that oxidation of intersystem electron-transport carriers might be insufficient for the induction of State 2-State 1 transition in wild type of Synechocystis under high light.
Collapse
Affiliation(s)
- Irina V Elanskaya
- Department of Genetics, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Alexander A Bulychev
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Evgeny P Lukashev
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Elena M Muronets
- Department of Genetics, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Eugene G Maksimov
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
| |
Collapse
|
3
|
Hajizadeh M, Golub M, Moldenhauer M, Matsarskaia O, Martel A, Porcar L, Maksimov E, Friedrich T, Pieper J. Solution Structures of Two Different FRP-OCP Complexes as Revealed via SEC-SANS. Int J Mol Sci 2024; 25:2781. [PMID: 38474026 DOI: 10.3390/ijms25052781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 02/02/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Photosynthetic organisms have established photoprotective mechanisms in order to dissipate excess light energy into heat, which is commonly known as non-photochemical quenching. Cyanobacteria utilize the orange carotenoid protein (OCP) as a high-light sensor and quencher to regulate the energy flow in the photosynthetic apparatus. Triggered by strong light, OCP undergoes conformational changes to form the active red state (OCPR). In many cyanobacteria, the back conversion of OCP to the dark-adapted state is assisted by the fluorescence recovery protein (FRP). However, the exact molecular events involving OCP and its interaction with FRP remain largely unraveled so far due to their metastability. Here, we use small-angle neutron scattering combined with size exclusion chromatography (SEC-SANS) to unravel the solution structures of FRP-OCP complexes using a compact mutant of OCP lacking the N-terminal extension (∆NTEOCPO) and wild-type FRP. The results are consistent with the simultaneous presence of stable 2:2 and 2:1 FRP-∆NTEOCPO complexes in solution, where the former complex type is observed for the first time. For both complex types, we provide ab initio low-resolution shape reconstructions and compare them to homology models based on available crystal structures. It is likely that both complexes represent intermediate states of the back conversion of OCP to its dark-adapted state in the presence of FRP, which are of transient nature in the photocycle of wild-type OCP. This study demonstrates the large potential of SEC-SANS in revealing the solution structures of protein complexes in polydisperse solutions that would otherwise be averaged, leading to unspecific results.
Collapse
Affiliation(s)
- Mina Hajizadeh
- Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu, Estonia
| | - Maksym Golub
- Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu, Estonia
| | - Marcus Moldenhauer
- Institute of Chemistry PC 14, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Olga Matsarskaia
- Institut Laue-Langevin, Avenue des Martyrs 71, CEDEX 9, 38042 Grenoble, France
| | - Anne Martel
- Institut Laue-Langevin, Avenue des Martyrs 71, CEDEX 9, 38042 Grenoble, France
| | - Lionel Porcar
- Institut Laue-Langevin, Avenue des Martyrs 71, CEDEX 9, 38042 Grenoble, France
| | - Eugene Maksimov
- Faculty of Biology, Lomonosov Moscow State University, 1-12 Leninskie Gory, 119991 Moscow, Russia
| | - Thomas Friedrich
- Institute of Chemistry PC 14, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Jörg Pieper
- Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu, Estonia
| |
Collapse
|
4
|
Likkei K, Moldenhauer M, Tavraz NN, Maksimov EG, Sluchanko NN, Friedrich T. Lipid composition and properties affect protein-mediated carotenoid uptake efficiency from membranes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184241. [PMID: 37866690 DOI: 10.1016/j.bbamem.2023.184241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 10/04/2023] [Accepted: 10/17/2023] [Indexed: 10/24/2023]
Abstract
Carotenoids are pigments of diverse functions ranging from coloration over light-harvesting to photoprotection. Yet, the number of carotenoid-binding proteins, which mobilize these pigments in physiological media, is limited, and the mechanisms of carotenoid mobilization are still not well understood. The same applies for the determinants of carotenoid uptake from membranes into carotenoproteins, especially regarding the dependence on the chemical properties of membrane lipids. Here, we investigate xanthophyll uptake capacity and kinetics of a paradigmatic carotenoid-binding protein, the homolog of the Orange Carotenoid Protein's C-terminal domain from Anabaena sp. PCC 7120 (AnaCTDH), using liposomes formed from defined lipid species and loaded with canthaxanthin (CAN) and echinenone (ECN), respectively. Phospholipids with different chain length and degree of saturation were investigated. The composition of carotenoid-loaded liposomes directly affected the incorporation yield and storage ratio of CAN and ECN as well as the rate of carotenoid uptake by AnaCTDH. Generally, saturated PC lipids were identified as unsuitable, and a high phase transition temperature of the lipids negatively affected the carotenoid incorporation and storage yield. For efficient carotenoid transfer, the velocity increases with increasing chain length or membrane thickness. An average transfer yield of 93 % and 43 % were obtained for the formation of AnaCTDH(CAN) and AnaCTDH(ECN) holoproteins, respectively. In summary, the most suitable lipids for the formation of AnaCTDH(CAN/ECN) holoproteins by carotenoid transfer from artificial liposomes are phosphatidylcholine (18:1) and phosphatidylglycerol (14:0). Thus, these two lipids provide the best conditions for further investigation of lipid-protein interaction and the carotenoid uptake process.
Collapse
Affiliation(s)
- Kristina Likkei
- Technische Universität Berlin, Institute of Chemistry PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Marcus Moldenhauer
- Technische Universität Berlin, Institute of Chemistry PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Neslihan N Tavraz
- Technische Universität Berlin, Institute of Chemistry PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Eugene G Maksimov
- Lomonosov Moscow State University, Faculty of Biology, Leninskie Gory 1-12, Moscow 119991, Russia
| | - Nikolai N Sluchanko
- Federal Research Center of Biotechnology of the Russian Academy of Sciences, A.N. Bach Institute of Biochemistry, Leninsky Prospect 33-1, Moscow 119071, Russia
| | - Thomas Friedrich
- Technische Universität Berlin, Institute of Chemistry PC 14, Straße des 17. Juni 135, 10623 Berlin, Germany.
| |
Collapse
|
5
|
Golub M, Pieper J. Recent Progress in Solution Structure Studies of Photosynthetic Proteins Using Small-Angle Scattering Methods. Molecules 2023; 28:7414. [PMID: 37959833 PMCID: PMC10650700 DOI: 10.3390/molecules28217414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 10/27/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
Utilized for gaining structural insights, small-angle neutron and X-ray scattering techniques (SANS and SAXS, respectively) enable an examination of biomolecules, including photosynthetic pigment-protein complexes, in solution at physiological temperatures. These methods can be seen as instrumental bridges between the high-resolution structural information achieved by crystallography or cryo-electron microscopy and functional explorations conducted in a solution state. The review starts with a comprehensive overview about the fundamental principles and applications of SANS and SAXS, with a particular focus on the recent advancements permitting to enhance the efficiency of these techniques in photosynthesis research. Among the recent developments discussed are: (i) the advent of novel modeling tools whereby a direct connection between SANS and SAXS data and high-resolution structures is created; (ii) the employment of selective deuteration, which is utilized to enhance spatial selectivity and contrast matching; (iii) the potential symbioses with molecular dynamics simulations; and (iv) the amalgamations with functional studies that are conducted to unearth structure-function relationships. Finally, reference is made to time-resolved SANS/SAXS experiments, which enable the monitoring of large-scale structural transformations of proteins in a real-time framework.
Collapse
Affiliation(s)
| | - Jörg Pieper
- Institute of Physics, University of Tartu, Wilhelm Ostwald Str. 1, 50411 Tartu, Estonia;
| |
Collapse
|
6
|
Tsoraev GV, Bukhanko A, Budylin GS, Shirshin EA, Slonimskiy YB, Sluchanko NN, Kloz M, Cherepanov DA, Shakina YV, Ge B, Moldenhauer M, Friedrich T, Golub M, Pieper J, Maksimov EG, Rubin AB. Stages of OCP-FRP Interactions in the Regulation of Photoprotection in Cyanobacteria, Part 1: Time-Resolved Spectroscopy. J Phys Chem B 2023; 127:1890-1900. [PMID: 36799909 DOI: 10.1021/acs.jpcb.2c07189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Most cyanobacteria utilize a water-soluble Orange Carotenoid Protein (OCP) to protect their light-harvesting complexes from photodamage. The Fluorescence Recovery Protein (FRP) is used to restore photosynthetic activity by inactivating OCP via dynamic OCP-FRP interactions, a multistage process that remains underexplored. In this work, applying time-resolved spectroscopy, we demonstrate that the interaction of FRP with the photoactivated OCP begins early in the photocycle. Interacting with the compact OCP state, FRP completely prevents the possibility of OCP domain separation and formation of the signaling state capable of interacting with the antenna. The structural element that prevents FRP binding and formation of the complex is the short α-helix at the beginning of the N-terminal domain of OCP, which masks the primary site in the C-terminal domain of OCP. We determined the rate of opening of this site and show that it remains exposed long after the relaxation of the red OCP states. Observations of the OCP transitions on the ms time scale revealed that the relaxation of the orange photocycle intermediates is accompanied by an increase in the interaction of the carotenoid keto group with the hydrogen bond donor tyrosine-201. Our data refine the current model of photoinduced OCP transitions and the interaction of its intermediates with FRP.
Collapse
Affiliation(s)
- Georgy V Tsoraev
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Antonina Bukhanko
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Gleb S Budylin
- Faculty of Physics, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia.,Laboratory of Clinical Biophotonics, Scientific and Technological Biomedical Park, Sechenov University, 119435 Moscow, Russia
| | - Evgeny A Shirshin
- Faculty of Physics, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Yury B Slonimskiy
- A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia
| | - Nikolai N Sluchanko
- A.N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia
| | - Miroslav Kloz
- ELI-Beamlines, Institute of Physics, Dolní Břežany, 252 41 Czech Republic
| | - Dmitry A Cherepanov
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 142432 Moscow, Russia.,A.N. Belozersky Institute of Physical-Chemical Biology, Moscow State University, 119991 Moscow, Russia
| | | | - Baosheng Ge
- China University of Petroleum (Huadong), College of Chemical Engineering, Qingdao 266580, PR China
| | - Marcus Moldenhauer
- Technische Universität Berlin, Institute of Chemistry PC14, 10623 Berlin, Germany
| | - Thomas Friedrich
- Technische Universität Berlin, Institute of Chemistry PC14, 10623 Berlin, Germany
| | - Maksym Golub
- Institute of Physics, University of Tartu, 50411 Tartu, Estonia
| | - Jörg Pieper
- Institute of Physics, University of Tartu, 50411 Tartu, Estonia
| | - Eugene G Maksimov
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Andrew B Rubin
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia
| |
Collapse
|
7
|
Golub M, Moldenhauer M, Matsarskaia O, Martel A, Grudinin S, Soloviov D, Kuklin A, Maksimov EG, Friedrich T, Pieper J. Stages of OCP-FRP Interactions in the Regulation of Photoprotection in Cyanobacteria, Part 2: Small-Angle Neutron Scattering with Partial Deuteration. J Phys Chem B 2023; 127:1901-1913. [PMID: 36815674 DOI: 10.1021/acs.jpcb.2c07182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
We used small-angle neutron scattering partially coupled with size-exclusion chromatography to unravel the solution structures of two variants of the Orange Carotenoid Protein (OCP) lacking the N-terminal extension (OCP-ΔNTE) and its complex formation with the Fluorescence Recovery Protein (FRP). The dark-adapted, orange form OCP-ΔNTEO is fully photoswitchable and preferentially binds the pigment echinenone. Its complex with FRP consists of a monomeric OCP component, which closely resembles the compact structure expected for the OCP ground state, OCPO. In contrast, the pink form OCP-ΔNTEP, preferentially binding the pigment canthaxanthin, is mostly nonswitchable. The pink OCP form appears to occur as a dimer and is characterized by a separation of the N- and C-terminal domains, with the canthaxanthin embedded only into the N-terminal domain. Therefore, OCP-ΔNTEP can be viewed as a prototypical model system for the active, spectrally red-shifted state of OCP, OCPR. The dimeric structure of OCP-ΔNTEP is retained in its complex with FRP. Small-angle neutron scattering using partially deuterated OCP-FRP complexes reveals that FRP undergoes significant structural changes upon complex formation with OCP. The observed structures are assigned to individual intermediates of the OCP photocycle in the presence of FRP.
Collapse
Affiliation(s)
- Maksym Golub
- Institute of Physics, University of Tartu, 50411 Tartu, Estonia
| | - Marcus Moldenhauer
- Institute of Chemistry PC 14, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Olga Matsarskaia
- Institut Laue-Langevin, Avenue des Martyrs 71, 38042 Cedex 9 Grenoble, France
| | - Anne Martel
- Institut Laue-Langevin, Avenue des Martyrs 71, 38042 Cedex 9 Grenoble, France
| | - Sergei Grudinin
- Université Grenoble Alpes, CNRS, Grenoble INP, LJK, 38000 Grenoble, France
| | - Dmytro Soloviov
- Faculty of Physics, Adam Mickiewicz University, ul. Wieniawskiego 1, 61-712 Poznan, Poland.,Institute for Safety Problems of Nuclear Power Plants, NAS of Ukraine, Kirova 36a, 07270 Chornobyl, Ukraine
| | - Alexander Kuklin
- Joint Institute for Nuclear Research, Joliot-Curie str. 6, 141980 Dubna, Russia.,Moscow Institute of Physics and Technology, Institutskiy per. 9, 141701 Dolgoprudny, Russia
| | - Eugene G Maksimov
- Department of Biophysics, M. V. Lomonosov Moscow State University, Vorob'jovy Gory 1-12, 119899 Moscow, Russia
| | - Thomas Friedrich
- Institute of Chemistry PC 14, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Jörg Pieper
- Institute of Physics, University of Tartu, 50411 Tartu, Estonia
| |
Collapse
|
8
|
Golub M, Moldenhauer M, Schmitt FJ, Lohstroh W, Friedrich T, Pieper J. Light-Induced Conformational Flexibility of the Orange Carotenoid Protein Studied by Quasielastic Neutron Scattering with In Situ Illumination. J Phys Chem Lett 2023; 14:295-301. [PMID: 36599148 DOI: 10.1021/acs.jpclett.2c03198] [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: 06/17/2023]
Abstract
The orange carotenoid protein plays a vital role in the photoprotection of cyanobacteria and exhibits a significant structural change upon photoactivation. A rarely considered aspect is the importance of internal protein dynamics in facilitating the structural transition to the active state. In this study, we use quasielastic neutron scattering under (in situ) blue light illumination for the first time to directly probe the protein dynamics of the orange carotenoid protein in the dark-adapted and active states. This shows that the localized internal dynamics of amino acid residues is significantly enhanced upon photoactivation. This is attributed to the photoinduced structural changes exposing larger areas of the protein surface to the solvent, thus resulting in a higher degree of motional freedom. However, the flexibility of the W288A mutant assumed to mimic the active state structure is found to be different, thus highlighting the importance of in situ experiments.
Collapse
Affiliation(s)
- Maksym Golub
- Institute of Physics, University of Tartu, W. Ostwald strasse 1, 50411 Tartu, Estonia
| | - Marcus Moldenhauer
- Technische Universität Berlin, Institute of Chemistry PC 14, Straße des 17, Juni 135, 10623 Berlin, Germany
| | - Franz-Josef Schmitt
- Martin-Luther-Universität Halle Wittenberg, Institute of Physics, Von-Danckelmann-Platz 3, 06120 Halle, Germany
| | - Wiebke Lohstroh
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstraße 1, 85748 Garching, Germany
| | - Thomas Friedrich
- Technische Universität Berlin, Institute of Chemistry PC 14, Straße des 17, Juni 135, 10623 Berlin, Germany
| | - Jörg Pieper
- Institute of Physics, University of Tartu, W. Ostwald strasse 1, 50411 Tartu, Estonia
| |
Collapse
|
9
|
Oligomerization processes limit photoactivation and recovery of the Orange Carotenoid Protein. Biophys J 2022; 121:2849-2872. [PMID: 35794830 PMCID: PMC9388578 DOI: 10.1016/j.bpj.2022.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 05/17/2022] [Accepted: 07/01/2022] [Indexed: 11/23/2022] Open
Abstract
The Orange Carotenoid Protein (OCP) is a photoactive protein involved in cyanobacterial photoprotection, by quenching of the excess of light harvested energy. The photoactivation mechanism remains elusive, in part due to absence of data pertaining to the timescales over which protein structural changes take place. It also remains unclear whether or not oligomerization of the dark-adapted and light-adapted OCP could play a role in the regulation of its energy quenching activity. Here, we probed photo-induced structural changes in OCP by a combination of static and time-resolved X-ray scattering and steady-state and transient optical spectroscopy in the visible range. Our results suggest that oligomerization partakes in regulation of the OCP photocycle, with different oligomers slowing down the overall thermal recovery of the dark-adapted state of OCP. They furthermore reveal that upon non-photoproductive excitation, a numbed-state forms, which remains in a non-photoexcitable structural state for at least ∼0.5 μs after absorption of a first photon.
Collapse
|
10
|
Golub M, Gätcke J, Subramanian S, Kölsch A, Darwish T, Howard JK, Feoktystov A, Matsarskaia O, Martel A, Porcar L, Zouni A, Pieper J. "Invisible" Detergents Enable a Reliable Determination of Solution Structures of Native Photosystems by Small-Angle Neutron Scattering. J Phys Chem B 2022; 126:2824-2833. [PMID: 35384657 DOI: 10.1021/acs.jpcb.2c01591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photosystems I (PSI) and II (PSII) are pigment-protein complexes capable of performing the light-induced charge separation necessary to convert solar energy into a biochemically storable form, an essential step in photosynthesis. Small-angle neutron scattering (SANS) is unique in providing structural information on PSI and PSII in solution under nearly physiological conditions without the need for crystallization or temperature decrease. We show that the reliability of the solution structure critically depends on proper contrast matching of the detergent belt surrounding the protein. Especially, specifically deuterated ("invisible") detergents are shown to be properly matched out in SANS experiments by a direct, quantitative comparison with conventional matching strategies. In contrast, protonated detergents necessarily exhibit incomplete matching so that related SANS results systematically overestimate the size of the membrane protein under study. While the solution structures obtained are close to corresponding high-resolution structures, we show that temperature and solution state lead to individual structural differences compared with high-resolution structures. We attribute these differences to the presence of a manifold of conformational substates accessible by protein dynamics under physiological conditions.
Collapse
Affiliation(s)
- M Golub
- Institute of Physics, University of Tartu, Wilhelm Ostwald str. 1, 50411 Tartu, Estonia
| | - J Gätcke
- Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - S Subramanian
- Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - A Kölsch
- Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - T Darwish
- National Deuteration Facility, Australian Nuclear Science and Technology Organization, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - J K Howard
- National Deuteration Facility, Australian Nuclear Science and Technology Organization, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - A Feoktystov
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstr. 1, 85748 Garching, Germany
| | - O Matsarskaia
- Institut Laue-Langevin, 71 Avenue des Martyrs CS 20156, 38042 Grenoble Cedex 9, France
| | - A Martel
- Institut Laue-Langevin, 71 Avenue des Martyrs CS 20156, 38042 Grenoble Cedex 9, France
| | - L Porcar
- Institut Laue-Langevin, 71 Avenue des Martyrs CS 20156, 38042 Grenoble Cedex 9, France
| | - A Zouni
- Humboldt-Universität zu Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - J Pieper
- Institute of Physics, University of Tartu, Wilhelm Ostwald str. 1, 50411 Tartu, Estonia
| |
Collapse
|
11
|
Sharawy M, Pigni NB, May ER, Gascón JA. A favorable path to domain separation in the orange carotenoid protein. Protein Sci 2022; 31:850-863. [PMID: 35000233 PMCID: PMC8927859 DOI: 10.1002/pro.4273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/24/2021] [Accepted: 01/03/2022] [Indexed: 11/10/2022]
Abstract
The orange carotenoid protein (OCP) is responsible for nonphotochemical quenching (NPQ) in cyanobacteria, a defense mechanism against potentially damaging effects of excess light conditions. This soluble two-domain protein undergoes profound conformational changes upon photoactivation, involving translocation of the ketocarotenoid inside the cavity followed by domain separation. Domain separation is a critical step in the photocycle of OCP because it exposes the N-terminal domain (NTD) to perform quenching of the phycobilisomes. Many details regarding the mechanism and energetics of OCP domain separation remain unknown. In this work, we apply metadynamics to elucidate the protein rearrangements that lead to the active, domain-separated, form of OCP. We find that translocation of the ketocarotenoid canthaxanthin has a profound effect on the energetic landscape and that domain separation only becomes favorable following translocation. We further explore, characterize, and validate the free energy surface (FES) using equilibrium simulations initiated from different states on the FES. Through pathway optimization methods, we characterize the most probable path to domain separation and reveal the barriers along that pathway. We find that the free energy barriers are relatively small (<5 kcal/mol), but the overall estimated kinetic rate is consistent with experimental measurements (>1 ms). Overall, our results provide detailed information on the requirement for canthaxanthin translocation to precede domain separation and an energetically feasible pathway to dissociation.
Collapse
Affiliation(s)
- Mahmoud Sharawy
- Department of Molecular and Cell BiologyUniversity of ConnecticutStorrsConnecticutUSA
| | - Natalia B. Pigni
- Department of ChemistryUniversity of ConnecticutStorrsConnecticutUSA
- Instituto de Ciencia y Tecnología de Alimentos Córdoba (ICYTAC‐CONICET)Ciudad UniversitariaCórdobaArgentina
| | - Eric R. May
- Department of Molecular and Cell BiologyUniversity of ConnecticutStorrsConnecticutUSA
| | - José A. Gascón
- Department of ChemistryUniversity of ConnecticutStorrsConnecticutUSA
| |
Collapse
|
12
|
Golub M, Lokstein H, Soloviov D, Kuklin A, Wieland DCF, Pieper J. Light-Harvesting Complex II Adopts Different Quaternary Structures in Solution as Observed Using Small-Angle Scattering. J Phys Chem Lett 2022; 13:1258-1265. [PMID: 35089716 DOI: 10.1021/acs.jpclett.1c03614] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The high-resolution crystal structure of the trimeric major light-harvesting complex of photosystem II (LHCII) is often perceived as the basis for understanding its light-harvesting and photoprotective functions. However, the LHCII solution structure and its oligomerization or aggregation state may generally differ from the crystal structure and, moreover, also depend on its functional state. In this regard, small-angle scattering experiments provide the missing link by offering structural information in aqueous solution at physiological temperatures. Herein, we use small-angle scattering to investigate the solution structures of two different preparations of solubilized LHCII employing the nonionic detergents n-octyl-β-d-glucoside (OG) and n-dodecyl-β-D-maltoside (β-DM). The data reveal that the LHCII-OG complex is equivalent to the trimeric crystal structure. Remarkably, however, we observe─for the first time─a stable oligomer composed of three LHCII trimers in the case of the LHCII-β-DM preparation, implying additional pigment-pigment interactions. The latter complex is assumed to mimic trimer-trimer interactions which play an important role in the context of photoprotective nonphotochemical quenching.
Collapse
Affiliation(s)
- Maksym Golub
- Institute of Physics, University of Tartu, Wilhelm Ostwald str. 1, 50411 Tartu, Estonia
| | - Heiko Lokstein
- Department of Chemical Physics and Optics, Charles University, Ke Karlovu 3, 121 16 Prague, Czech Republic
| | - Dmytro Soloviov
- Joint Institute for Nuclear Research, Joliot-Curie str. 6, 141980 Dubna, Russia
- Moscow Institute of Physics and Technology, Institutskiy per. 9, 141701 Dolgoprudny, Russia
- Institute for Safety Problems of Nuclear Power Plants NAS of Ukraine, Lysogirska str. 12, 03028 Kyiv, Ukraine
| | - Alexander Kuklin
- Joint Institute for Nuclear Research, Joliot-Curie str. 6, 141980 Dubna, Russia
- Moscow Institute of Physics and Technology, Institutskiy per. 9, 141701 Dolgoprudny, Russia
| | - D C Florian Wieland
- Helmholtz Zentrum Geesthacht, Institute for Materials Research, Department for Metallic Biomaterials, 21502 Geesthacht, Germany
| | - Jörg Pieper
- Institute of Physics, University of Tartu, Wilhelm Ostwald str. 1, 50411 Tartu, Estonia
| |
Collapse
|
13
|
Nagy G, Garab G. Neutron scattering in photosynthesis research: recent advances and perspectives for testing crop plants. PHOTOSYNTHESIS RESEARCH 2021; 150:41-49. [PMID: 32488447 PMCID: PMC8556207 DOI: 10.1007/s11120-020-00763-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/25/2020] [Indexed: 05/05/2023]
Abstract
The photosynthetic performance of crop plants under a variety of environmental factors and stress conditions, at the fundamental level, depends largely on the organization and structural flexibility of thylakoid membranes. These highly organized membranes accommodate virtually all protein complexes and additional compounds carrying out the light reactions of photosynthesis. Most regulatory mechanisms fine-tuning the photosynthetic functions affect the organization of thylakoid membranes at different levels of the structural complexity. In order to monitor these reorganizations, non-invasive techniques are of special value. On the mesoscopic scale, small-angle neutron scattering (SANS) has been shown to deliver statistically and spatially averaged information on the periodic organization of the thylakoid membranes in vivo and/or, in isolated thylakoids, under physiologically relevant conditions, without fixation or staining. More importantly, SANS investigations have revealed rapid reversible reorganizations on the timescale of several seconds and minutes. In this paper, we give a short introduction into the basics of SANS technique, advantages and limitations, and briefly overview recent advances and potential applications of this technique in the physiology and biotechnology of crop plants. We also discuss future perspectives of neutron crystallography and different neutron scattering techniques, which are anticipated to become more accessible and of more use in photosynthesis research at new facilities with higher fluxes and innovative instrumentation.
Collapse
Affiliation(s)
- Gergely Nagy
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, POB 49, 1525, Budapest, Hungary.
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, POB 521, 6701, Szeged, Hungary.
- Department of Physics, Faculty of Science, Ostrava University, Chittussiho 10, Ostrava - Slezská, 710 0, Ostrava, Czech Republic.
| |
Collapse
|
14
|
Insights into Solution Structures of Photosynthetic Protein Complexes from Small-Angle Scattering Methods. CRYSTALS 2021. [DOI: 10.3390/cryst11020203] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
High-resolution structures of photosynthetic pigment–protein complexes are often determined using crystallography or cryo-electron microscopy (cryo-EM), which are restricted to the use of protein crystals or to low temperatures, respectively. However, functional studies and biotechnological applications of photosystems necessitate the use of proteins isolated in aqueous solution, so that the relevance of high-resolution structures has to be independently verified. In this regard, small-angle neutron and X-ray scattering (SANS and SAXS, respectively) can serve as the missing link because of their capability to provide structural information for proteins in aqueous solution at physiological temperatures. In the present review, we discuss the principles and prototypical applications of SANS and SAXS using the photosynthetic pigment–protein complexes phycocyanin (PC) and Photosystem I (PSI) as model systems for a water-soluble and for a membrane protein, respectively. For example, the solution structure of PSI was studied using SAXS and SANS with contrast matching. A Guinier analysis reveals that PSI in solution is virtually free of aggregation and characterized by a radius of gyration of about 75 Å. The latter value is about 10% larger than expected from the crystal structure. This is corroborated by an ab initio structure reconstitution, which also shows a slight expansion of Photosystem I in buffer solution at room temperature. In part, this may be due to conformational states accessible by thermally activated protein dynamics in solution at physiological temperatures. The size of the detergent belt is derived by comparison with SANS measurements without detergent match, revealing a monolayer of detergent molecules under proper solubilization conditions.
Collapse
|
15
|
Golub M, Hussein R, Ibrahim M, Hecht M, Wieland DCF, Martel A, Machado B, Zouni A, Pieper J. Solution Structure of the Detergent-Photosystem II Core Complex Investigated by Small-Angle Scattering Techniques. J Phys Chem B 2020; 124:8583-8592. [PMID: 32816484 DOI: 10.1021/acs.jpcb.0c07169] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Albeit achieving the X-ray diffraction structure of dimeric photosystem II core complexes (dPSIIcc) at the atomic resolution, the nature of the detergent belt surrounding dPSIIcc remains ambiguous. Therefore, the solution structure of the whole detergent-protein complex of dPSIIcc of Thermosynechococcus elongatus (T. elongatus) solubilized in n-dodecyl-ß-d-maltoside (ßDM) was investigated by a combination of small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) with contrast variation. First, the structure of dPSIIcc was studied separately in SANS experiments using a contrast of 5% D2O. Guinier analysis reveals that the dPSIIcc solution is virtually free of aggregation in the studied concentration range of 2-10 mg/mL dPSIIcc, and characterized by a radius of gyration of 62 Å. A structure reconstitution shows that dPSIIcc in buffer solution widely retains the crystal structure reported by X-ray free electron laser studies at room temperature with a slight expansion of the entire protein. Additional SANS experiments on dPSIIcc samples in a buffer solution containing 75% D2O provide information about the size and shape of the whole detergent-dPSIIcc. The maximum position of P(r) function increases to 68 Å, i.e., it is about 6 Å larger than that of dPSIIcc only, thus indicating the presence of an additional structure. Thus, it can be concluded that dPSIIcc is surrounded by a monomolecular belt of detergent molecules under appropriate solubilization conditions. The homogeneity of the ßDM-dPSIIcc solutions was also verified using dynamic light scattering. Complementary SAXS experiments indicate the presence of unbound detergent micelles by a separate peak consistent with a spherical shape possessing a radius of about 40 Å. The latter structure also contributes to the SANS data but rather broadens the SANS curve artificially. Without the simultaneous inspection of SANS and SAXS data, this effect may lead to an apparent underestimation of the size of the PS II-detergent complex. The formation of larger unbound detergent aggregates in solution prior to crystallization may have a significant effect on the crystal formation or quality of the ßDM-dPSIIcc.
Collapse
Affiliation(s)
- Maksym Golub
- Institute of Physics, University of Tartu, Wilhelm Ostwald str. 1, 50411 Tartu, Estonia
| | - Rana Hussein
- Humboldt Universität zu Berlin, Philipp Str. 13, 10115 Berlin, Germany
| | - Mohamed Ibrahim
- Humboldt Universität zu Berlin, Philipp Str. 13, 10115 Berlin, Germany
| | - Max Hecht
- Institute of Physics, University of Tartu, Wilhelm Ostwald str. 1, 50411 Tartu, Estonia
| | | | - Anne Martel
- Institut Laue-Langevin, 71 avenue des Martyrs, 38043 Grenoble, France
| | - Barbara Machado
- European Synchrotron Radiation Facility, 71 avenue des Martyrs, 38043 Grenoble, France
| | - Athina Zouni
- Humboldt Universität zu Berlin, Philipp Str. 13, 10115 Berlin, Germany
| | - Jörg Pieper
- Institute of Physics, University of Tartu, Wilhelm Ostwald str. 1, 50411 Tartu, Estonia
| |
Collapse
|
16
|
Golub M, Moldenhauer M, Schmitt FJ, Lohstroh W, Maksimov EG, Friedrich T, Pieper J. Solution Structure and Conformational Flexibility in the Active State of the Orange Carotenoid Protein. Part II: Quasielastic Neutron Scattering. J Phys Chem B 2019; 123:9536-9545. [PMID: 31550157 DOI: 10.1021/acs.jpcb.9b05073] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Orange carotenoid proteins (OCPs), which are protecting cyanobacterial light-harvesting antennae from photodamage, undergo a pronounced structural change upon light absorption. In addition, the active state is anticipated to boost a significantly higher molecular flexibility similar to a "molten globule" state. Here, we used quasielastic neutron scattering to directly characterize the vibrational and conformational molecular dynamics of OCP in its ground and active states, respectively, on the picosecond time scale. At a temperature of 100 K, we observe mainly (vibronic) inelastic features with peak energies at 5 and 6 meV (40 and 48 cm-1, respectively). At physiological temperatures, however, two (Lorentzian) quasielastic components represent localized protein motions, that is, stochastic structural fluctuations of protein side chains between various conformational substates of the protein. Global diffusion of OCP is not observed on the given time scale. The slower Lorentzian component is affected by illumination and can be well-characterized by a jump-diffusion model. While the jump diffusion constant D is (2.82 ± 0.01) × 10-5 cm2/s at 300 K in the ground state, it is increased by ∼20% to (3.48 ± 0.01) × 10-5 cm2/s in the active state, revealing a strong enhancement of molecular mobility. The increased mobility is also reflected in the average atomic mean square displacement ⟨u2⟩; we determine a ⟨u2⟩ of 1.47 ± 0.05 Å in the ground state, but 1.86 ± 0.05 Å in the active state (at 300 K). This effect is assigned to two factors: (i) the elongated structure of the active state with two widely separated protein domains is characterized by a larger number of surface residues with a concomitantly higher degree of motional freedom and (ii) a larger number of hydration water molecules bound at the surface of the protein. We thus conclude that the active state of the orange carotenoid protein displays an enhanced conformational dynamics. The higher degree of flexibility may provide additional channels for nonradiative decay so that harmful excess energy can be more efficiently converted to heat.
Collapse
Affiliation(s)
- Maksym Golub
- Institute of Physics , University of Tartu , 50411 Tartu , Estonia
| | - Marcus Moldenhauer
- Technische Universität Berlin , Institute of Chemistry, Physical Chemistry , 10623 Berlin , Germany
| | - Franz-Josef Schmitt
- Technische Universität Berlin , Institute of Chemistry, Physical Chemistry , 10623 Berlin , Germany
| | - Wiebke Lohstroh
- Heinz Maier-Leibnitz Zentrum , Technische Universität München , Garching , Germany
| | - Eugene G Maksimov
- Department of Biophysics , M. V. Lomonosov Moscow State University , Moscow , Russia
| | - Thomas Friedrich
- Technische Universität Berlin , Institute of Chemistry, Physical Chemistry , 10623 Berlin , Germany
| | - Jörg Pieper
- Institute of Physics , University of Tartu , 50411 Tartu , Estonia
| |
Collapse
|