1
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Cisse A, Schachner-Nedherer AL, Appel M, Beck C, Ollivier J, Leitinger G, Prassl R, Kornmueller K, Peters J. Dynamics of Apolipoprotein B-100 in Interaction with Detergent Probed by Incoherent Neutron Scattering. J Phys Chem Lett 2021; 12:12402-12410. [PMID: 34939807 DOI: 10.1021/acs.jpclett.1c03141] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Apolipoprotein B-100 (apo B-100) is the protein moiety of both low- and very-low-density lipoproteins, whose role is crucial to cholesterol and triglyceride transport. Aiming at the molecular dynamics' details of apo B-100, scarcely studied, we performed elastic and quasi-elastic incoherent neutron scattering (EINS, QENS) experiments combining different instruments and time scales. Similar to classical membrane proteins, the solubilization results in remaining detergent, here Nonidet P-40 (NP40). Therefore, we propose a framework for QENS studies of protein-detergent complexes, with the introduction of a combined model, including the experimental apo B-100/NP40 ratio. Relying on the simultaneous analysis of all QENS amplitudes, this approach is sensitive enough to separate both contributions. Its application identified two points: (i) apo B-100 slow dynamics and (ii) the acceleration of NP40 dynamics in the presence of apo B-100. Direct translation of the exposed methodology now makes the investigation of more membrane proteins by neutron spectroscopy achievable.
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Affiliation(s)
- Aline Cisse
- Université Grenoble Alpes, CNRS, LiPhy, 38000 Grenoble, France
- Institut Laue Langevin, 38042 Grenoble, France
| | | | | | - Christian Beck
- Institut Laue Langevin, 38042 Grenoble, France
- Institut of Applied Physics, University of Tübingen, 72076 Tübingen, Germany
| | | | | | | | | | - Judith Peters
- Université Grenoble Alpes, CNRS, LiPhy, 38000 Grenoble, France
- Institut Laue Langevin, 38042 Grenoble, France
- Institut Universitaire de France, 75231 Paris, France
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2
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Zsiros O, Nagy G, Patai R, Solymosi K, Gasser U, Polgár TF, Garab G, Kovács L, Hörcsik ZT. Similarities and Differences in the Effects of Toxic Concentrations of Cadmium and Chromium on the Structure and Functions of Thylakoid Membranes in Chlorella variabilis. FRONTIERS IN PLANT SCIENCE 2020; 11:1006. [PMID: 32733513 PMCID: PMC7358611 DOI: 10.3389/fpls.2020.01006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 06/19/2020] [Indexed: 05/26/2023]
Abstract
Trace metal contaminations in natural waters, wetlands, and wastewaters pose serious threats to aquatic ecosystems-mainly via targeting microalgae. In this work, we investigated the effects of toxic amounts of chromium and cadmium ions on the structure and function of the photosynthetic machinery of Chlorella variabilis cells. To halt the propagation of cells, we used high concentrations of Cd and Cr, 50-50 mg L-1, in the forms of CdCl2 x 2.5 H2O and K2Cr2O7, respectively. Both treatments led to similar, about 50% gradual diminishment of the chlorophyll contents of the cells in 48 h, which was, however, accompanied by a small (~10%) but statistically significant enrichment (Cd) and loss (Cr) of ß-carotene. Both Cd and Cr inhibited the activity of photosystem II (PSII)-but with more severe inhibitions with Cr. On the contrary, the PsbA (D1) protein of PSII and the PsbO protein of the oxygen-evolving complex were retained more in Cr-treated cells than in the presence of Cd. These data and the higher susceptibility of P700 redox transients in Cr-treated cells suggest that, unlike with Cd, PSII is not the main target in the photochemical apparatus. These differences at the level of photochemistry also brought about dissimilarities at higher levels of the structural complexity of the photosynthetic apparatus. Circular dichroism (CD) spectroscopy measurements revealed moderate perturbations in the macro-organization of the protein complexes-with more pronounced decline in Cd-treated cells than in the cells with Cr. Also, as reflected by transmission electron microscopy and small-angle neutron scattering, the thylakoid membranes suffered shrinking and were largely fragmented in Cd-treated cells, whereas no changes could be discerned with Cr. The preservation of integrity of membranes in Cr-treated cells was most probably aided by high proportion of the de-epoxidized xanthophylls, which were absent with Cd. It can thus be concluded that beside strong similarities of the toxic effects of Cr and Cd, the response of the photosynthetic machinery of C. variabilis to these two trace metal ions substantially differ from each other-strongly suggesting different inhibitory and protective mechanisms following the primary toxic events.
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Affiliation(s)
- Ottó Zsiros
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Gergely Nagy
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, Villigen, Switzerland
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Budapest, Hungary
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Roland Patai
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Katalin Solymosi
- Department of Plant Anatomy, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Urs Gasser
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Villigen PSI, Villigen, Switzerland
| | - Tamás F. Polgár
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Department of Physics, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - László Kovács
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Zsolt Tibor Hörcsik
- Department of Biology Nyíregyháza, Institute of Environmental Sciences, University of Nyíregyháza, Nyíregyháza, Hungary
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3
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Dynamics Properties of Photosynthetic Microorganisms Probed by Incoherent Neutron Scattering. Biophys J 2019; 116:1759-1768. [PMID: 31003761 DOI: 10.1016/j.bpj.2019.03.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 03/18/2019] [Accepted: 03/20/2019] [Indexed: 01/06/2023] Open
Abstract
Studies on the dynamical properties of photosynthetic membranes of land plants and purple bacteria have been previously performed by neutron spectroscopy, revealing a tight coupling between specific photochemical reactions and macromolecular dynamics. Here, we probed the intrinsic dynamics of biotechnologically useful mutants of the green alga Chlamydomonas reinhardtii by incoherent neutron scattering coupled with prompt chlorophyll fluorescence experiments. We brought to light that single amino acid replacements in the plastoquinone (PQ)-binding niche of the photosystem II D1 protein impair electron transport (ET) efficiency between quinones and confer increased flexibility to the host membranes, expanding to the entire cells. Hence, a more flexible environment in the PQ-binding niche has been associated to a less efficient ET. A similar function/dynamics relationship was also demonstrated in Rhodobacter sphaeroides reaction centers having inhibited ET, indicating that flexibility at the quinones region plays a crucial role in evolutionarily distant organisms. Instead, a different functional/dynamical correlation was observed in algal mutants hosting a single amino acid replacement residing in a D1 domain far from the PQ-binding niche. Noteworthy, this mutant displayed the highest degree of flexibility, and besides having a nativelike ET efficiency in physiological conditions, it acquired novel, to our knowledge, phenotypic traits enabling it to preserve a high maximal quantum yield of photosystem II photochemistry in extreme habitats. Overall, in the nanosecond timescale, the degree of the observed flexibility is related to the mutation site; in the picosecond timescale, we highlighted the presence of a more pronounced dynamic heterogeneity in all mutants compared to the native cells, which could be related to a marked chemically heterogeneous environment.
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4
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Golub M, Guillon V, Gotthard G, Zeller D, Martinez N, Seydel T, Koza MM, Lafaye C, Clavel D, von Stetten D, Royant A, Peters J. Dynamics of a family of cyan fluorescent proteins probed by incoherent neutron scattering. J R Soc Interface 2019; 16:20180848. [PMID: 30836899 DOI: 10.1098/rsif.2018.0848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cyan fluorescent proteins (CFPs) are variants of green fluorescent proteins in which the central tyrosine of the chromophore has been replaced by a tryptophan. The increased bulk of the chromophore within a compact protein and the change in the positioning of atoms capable of hydrogen bonding have made it difficult to optimize their fluorescence properties, which took approximately 15 years between the availability of the first useable CFP, enhanced cyan fluorescent protein (ECFP), and that of a variant with almost perfect fluorescence efficiency, mTurquoise2. To understand the molecular bases of the progressive improvement in between these two CFPs, we have studied by incoherent neutron scattering the dynamics of five different variants exhibiting progressively increased fluorescence efficiency along the evolution pathway. Our results correlate well with the analysis of the previously determined X-ray crystallographic structures, which show an increase in flexibility between ECFP and the second variant, Cerulean, which is then hindered in the three later variants, SCFP3A (Super Cyan Fluorescent Protein 3A), mTurquoise and mTurquoise2. This confirms that increasing the rigidity of the direct environment of the fluorescent chromophore is not the sole parameter leading to brighter fluorescent proteins and that increased flexibility in some cases may be helpful.
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Affiliation(s)
- Maksym Golub
- 1 Institut Laue Langevin , 71 avenue des Martyrs, 38042 Grenoble Cedex 9 , France.,2 Univ. Grenoble Alpes, CNRS, CEA, IBS (Institut de Biologie Structurale) , 38000 Grenoble , France
| | - Virginia Guillon
- 2 Univ. Grenoble Alpes, CNRS, CEA, IBS (Institut de Biologie Structurale) , 38000 Grenoble , France
| | | | - Dominik Zeller
- 1 Institut Laue Langevin , 71 avenue des Martyrs, 38042 Grenoble Cedex 9 , France.,4 Laboratoire Interdisciplinaire de Physique, Univ. Grenoble Alpes, CNRS , 38000 Grenoble , France
| | - Nicolas Martinez
- 1 Institut Laue Langevin , 71 avenue des Martyrs, 38042 Grenoble Cedex 9 , France.,2 Univ. Grenoble Alpes, CNRS, CEA, IBS (Institut de Biologie Structurale) , 38000 Grenoble , France
| | - Tilo Seydel
- 1 Institut Laue Langevin , 71 avenue des Martyrs, 38042 Grenoble Cedex 9 , France
| | - Michael M Koza
- 1 Institut Laue Langevin , 71 avenue des Martyrs, 38042 Grenoble Cedex 9 , France
| | - Céline Lafaye
- 2 Univ. Grenoble Alpes, CNRS, CEA, IBS (Institut de Biologie Structurale) , 38000 Grenoble , France
| | - Damien Clavel
- 2 Univ. Grenoble Alpes, CNRS, CEA, IBS (Institut de Biologie Structurale) , 38000 Grenoble , France
| | | | - Antoine Royant
- 2 Univ. Grenoble Alpes, CNRS, CEA, IBS (Institut de Biologie Structurale) , 38000 Grenoble , France.,3 European Synchrotron Radiation Facility , 38043 Grenoble , France
| | - Judith Peters
- 1 Institut Laue Langevin , 71 avenue des Martyrs, 38042 Grenoble Cedex 9 , France.,4 Laboratoire Interdisciplinaire de Physique, Univ. Grenoble Alpes, CNRS , 38000 Grenoble , France
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5
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Golub M, Pieper J, Peters J, Kangur L, Martin EC, Hunter CN, Freiberg A. Picosecond Dynamical Response to a Pressure-Induced Break of the Tertiary Structure Hydrogen Bonds in a Membrane Chromoprotein. J Phys Chem B 2019; 123:2087-2093. [PMID: 30739452 DOI: 10.1021/acs.jpcb.8b11196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We used elastic incoherent neutron scattering (EINS) to find out if structural changes accompanying local hydrogen bond rupture are also reflected in global dynamical response of the protein complex. Chromatophore membranes from LH2-only strains of the photosynthetic bacterium Rhodobacter sphaeroides, with spheroidenone or neurosporene as the major carotenoids, were subjected to high hydrostatic pressure at ambient temperature. Optical spectroscopy conducted at high pressure confirmed rupture of tertiary structure hydrogen bonds. In parallel, we used EINS to follow average motions of the hydrogen atoms in LH2, which reflect the flexibility of this complex. A decrease of the average atomic mean square displacements of hydrogen atoms was observed up to a pressure of 5 kbar in both carotenoid samples due to general stiffening of protein structures, while at higher pressures a slight increase of the displacements was detected in the neurosporene mutant LH2 sample only. These data show a correlation between the local pressure-induced breakage of H-bonds, observed in optical spectra, with the altered protein dynamics monitored by EINS. The slightly higher compressibility of the neurosporene mutant sample shows that even subtle alterations of carotenoids are manifested on a larger scale and emphasize a close connection between the local structure and global dynamics of this membrane protein complex.
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Affiliation(s)
- Maksym Golub
- Institute of Physics , University of Tartu , W. Ostwald Str. 1 , 50411 Tartu , Estonia
| | - Jörg Pieper
- Institute of Physics , University of Tartu , W. Ostwald Str. 1 , 50411 Tartu , Estonia
| | - Judith Peters
- Institut Laue Langevin , F-38042 Grenoble Cedex 9 , France.,University Grenoble Alpes, CNRS, LIPhy , 38000 Grenoble , France
| | - Liina Kangur
- Institute of Physics , University of Tartu , W. Ostwald Str. 1 , 50411 Tartu , Estonia
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology , University of Sheffield , S10 2TN Sheffield , U.K
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology , University of Sheffield , S10 2TN Sheffield , U.K
| | - Arvi Freiberg
- Institute of Physics , University of Tartu , W. Ostwald Str. 1 , 50411 Tartu , Estonia.,Institute of Molecular and Cell Biology , University of Tartu , Riia 23 , 51010 Tartu , Estonia
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6
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Peters J, Marion J, Becher FJ, Trapp M, Gutberlet T, Bicout DJ, Heimburg T. Thermodynamics of lipid multi-lamellar vesicles in presence of sterols at high hydrostatic pressure. Sci Rep 2017; 7:15339. [PMID: 29127413 PMCID: PMC5681575 DOI: 10.1038/s41598-017-15582-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 10/30/2017] [Indexed: 01/28/2023] Open
Abstract
We compared the effect of cholesterol at different concentration on the phase behaviour of DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) multilamellar vesicles. We used pressure perturbation differential scanning calorimetry (PPC) that studies a system on the whole by giving access to relevant thermodynamic quantities, and elastic incoherent neutron scattering (EINS) that probes local motions of a system at the atomic level by allowing extraction of dynamical parameters. PPC revealed that the volume expansion coefficient of DMPC and DMPC/Cholesterol samples with 13 and 25 mol% cholesterol is a linear function of the heat capacity measured by differential scanning calorimetry. Neutron backscattering spectroscopy showed that the mean square displacements of H atoms do exhibit an increase with temperature and a decrease under increasing pressure. Cholesterol added at concentrations of 25 and 50 mol% led to suppression of the main phase transition. Taking advantage of these results, the present study aims (i) to show that calorimetry and EINS using the Bicout and Zaccai model equally permit to get access to thermodynamic quantities characterizing pure DMPC and DMPC/cholesterol mixtures, thus directly confirming the theoretical method, and (ii) to validate our approach as function of temperature and of pressure, as both are equally important and complementary thermodynamic variables.
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Affiliation(s)
- J Peters
- Univ. Grenoble Alpes, LiPhy, 140 Rue de la Physique, 38402, Saint-Martin-d'Hères, France. .,Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042, Grenoble cedex 9, France.
| | - J Marion
- Univ. Grenoble Alpes, LiPhy, 140 Rue de la Physique, 38402, Saint-Martin-d'Hères, France.,Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042, Grenoble cedex 9, France
| | - F J Becher
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100, Copenhagen, Denmark.,Department of Chemistry, University of Cambridge, Lensfield Rd, Cambridge, CB2 1EW, UK
| | - M Trapp
- Helmholtz-Zentrum Berlin für Materialien und Energie, Lise-Meitner Campus, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - T Gutberlet
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85748, Garching, Germany
| | - D J Bicout
- Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042, Grenoble cedex 9, France.,Biomathématiques et épidémiologie, EPSP - TIMC-IMAG, UMR CNRS 5525, Université Grenoble Alpes, VetAgro Sup Lyon, 69280, Marcy l'Etoile, France
| | - T Heimburg
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100, Copenhagen, Denmark
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7
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Peters J, Marion J, Natali F, Kats E, Bicout DJ. The Dynamical Transition of Lipid Multilamellar Bilayers as a Matter of Cooperativity. J Phys Chem B 2017. [PMID: 28650664 DOI: 10.1021/acs.jpcb.7b05167] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The present study is the application of a two-state model formerly developed by Bicout and Zaccai [ Bicout , D. J. and Zaccai , G. Biophys. J. 2001 , 80 ( 3 ), 1115 - 1123 ] to describe the dynamical transition exhibited in the atomic mean square displacements of biological samples in terms of dynamic and thermodynamic parameters. Data were obtained by elastic incoherent neutron scattering on 1,2-dimyristoyl-sn-glycero-3-phosphocholine lipid membranes in various hydration states and on one partially per-deuterated lipid membrane. Fitting the data with the model allowed investigating which parts of lipid molecules were mainly involved in the dynamical transition, heads, tails, or both. Clear differences were found between the fully protonated and partially deuterated membranes. These findings shed light on the question of what is the degree of dynamical cooperativity of the atoms during the transition. Whereas the level of hydration does not significantly affect it, as the dry, the intermediate dry, and fully hydrated membranes all undergo a rather broad transition, the transition of the lipid tails is much sharper and sets in at much lower temperature than that of the heads. Therefore, the dynamical cooperativity appears high among the particles in the tails. Moreover, the transition of the lipid tails has to be completed first before the one of the head groups starts.
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Affiliation(s)
- Judith Peters
- Université Grenoble Alpes , LiPhy, 140 rue de la physique, 38402 Saint Martin d'Hères, France.,Institut Laue-Langevin , 71 avenue des Martyrs, CS 20156, 38042 Grenoble cedex 9, France
| | - Jérémie Marion
- Institut Laue-Langevin , 71 avenue des Martyrs, CS 20156, 38042 Grenoble cedex 9, France.,Université Grenoble Alpes , IBS, 71 avenue des Martyrs, CS 10090, 38044 Grenoble, France
| | - Francesca Natali
- Institut Laue-Langevin , 71 avenue des Martyrs, CS 20156, 38042 Grenoble cedex 9, France.,CNR-IOM, OGG , 71 avenue des Martyrs, CS 20156, 38042 Grenoble cedex 9, France
| | - Efim Kats
- Institut Laue-Langevin , 71 avenue des Martyrs, CS 20156, 38042 Grenoble cedex 9, France.,Landau Institute for Theoretical Physics, RAS , 142432, Chernogolovka, Moscow region, Russia
| | - Dominique J Bicout
- Institut Laue-Langevin , 71 avenue des Martyrs, CS 20156, 38042 Grenoble cedex 9, France.,Biomathématiques et épidémiologie, EPSP - TIMC-IMAG, UMR CNRS 5525, Université Grenoble Alpes , VetAgro Sup Lyon, 69280 Marcy l'Etoile, France
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8
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Lambreva MD, Russo D, Polticelli F, Scognamiglio V, Antonacci A, Zobnina V, Campi G, Rea G. Structure/function/dynamics of photosystem II plastoquinone binding sites. Curr Protein Pept Sci 2015; 15:285-95. [PMID: 24678671 PMCID: PMC4030317 DOI: 10.2174/1389203715666140327104802] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 11/22/2013] [Accepted: 03/16/2014] [Indexed: 11/22/2022]
Abstract
Photosystem II (PSII)
continuously attracts the attention of researchers aiming to unravel the riddle
of its functioning and efficiency fundamental for all life on Earth. Besides, an
increasing number of biotechnological applications have been envisaged
exploiting and mimicking the unique properties of this macromolecular
pigment-protein complex. The PSII organization and working principles have
inspired the design of electrochemical water splitting schemes and charge
separating triads in energy storage systems as well as biochips and sensors for
environmental, agricultural and industrial screening of toxic compounds. An
intriguing opportunity is the development of sensor devices, exploiting native
or manipulated PSII complexes or ad hoc synthesized polypeptides
mimicking the PSII reaction centre proteins as bio-sensing elements. This review
offers a concise overview of the recent improvements in the understanding of
structure and function of PSII donor side, with focus on the interactions of the
plastoquinone cofactors with the surrounding environment and operational
features. Furthermore, studies focused on photosynthetic proteins
structure/function/dynamics and computational analyses aimed at rational design
of high-quality bio-recognition elements in biosensor devices are discussed.
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Affiliation(s)
| | | | | | | | | | | | | | - Giuseppina Rea
- Institute of Crystallography, National Research Council, Monterotondo, Italy.
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9
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Pieper J. The functional role of protein dynamics in photosynthetic reaction centers investigated by elastic and quasielastic neutron scattering. EPJ WEB OF CONFERENCES 2015. [DOI: 10.1051/epjconf/20158302013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Trapp M, Marion J, Tehei M, Demé B, Gutberlet T, Peters J. High hydrostatic pressure effects investigated by neutron scattering on lipid multilamellar vesicles. Phys Chem Chem Phys 2014; 15:20951-6. [PMID: 24201561 DOI: 10.1039/c3cp52762j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of high hydrostatic pressure on the structure and dynamics of model membrane systems were investigated using neutron scattering. Diffraction experiments show shifts of the pre- and main-phase transitions of multilamellar vesicles of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) to higher temperatures with increased pressure which are close to results observed previously by other techniques, namely (10.4 ± 1.0) K kbar(-1) and (20.0 ± 0.5) K kbar(-1) for the two transitions. Backscattering spectroscopy reveals that the mean square displacements in the liquid phase are about 10% smaller at 300 bar and about 20% smaller at 600 bar compared to atmospheric pressure, whereas in the gel phase below the main phase transition the mean square displacements show a smaller difference in the dynamics of the three pressure values within the studied pressure range.
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Affiliation(s)
- Marcus Trapp
- Angewandte Physikalische Chemie, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
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11
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Bousset L, Brewee C, Melki R, Migliardo F. Dynamical properties of α-synuclein in soluble and fibrillar forms by Quasi Elastic Neutron Scattering. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:1307-16. [PMID: 24768772 DOI: 10.1016/j.bbapap.2014.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 03/24/2014] [Accepted: 04/14/2014] [Indexed: 10/25/2022]
Abstract
In the present paper, Quasi Elastic Neutron Scattering (QENS) results, gathered at different energy resolution values at the ISIS Facility (RAL, UK), on α-synuclein in soluble and fibrillar forms as a function of temperature and exchanged wave-vector Q are shown. The measurements reveal a different dynamic behavior of the soluble and fibrillar forms of α-synuclein as a function of thermal stress. In more detail, the dynamics of each protein form reflects its own complex conformational heterogeneity. Furthermore, the effect of a well known bioprotectant, trehalose, that influences α-synuclein fibrillation, on both soluble and fibrillar forms of α-synuclein is discussed.
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Affiliation(s)
- Luc Bousset
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, Bat 34, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Clémence Brewee
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, Bat 34, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Ronald Melki
- Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, Bat 34, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Federica Migliardo
- Department of Physics and Earth Sciences, University of Messina, Viale D'Alcontres 31, 98166 Messina, Italy.
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12
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Migliardo F, Salmeron C, Bayan N. A neutron scattering study on the stability of trehalose mycolates under thermal stress. Chem Phys 2013. [DOI: 10.1016/j.chemphys.2012.12.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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13
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Peters J, Giudici-Orticoni MT, Zaccai G, Guiral M. Dynamics measured by neutron scattering correlates with the organization of bioenergetics complexes in natural membranes from hyperthermophile and mesophile bacteria. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2013; 36:78. [PMID: 23880731 DOI: 10.1140/epje/i2013-13078-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 02/01/2013] [Accepted: 02/26/2013] [Indexed: 06/02/2023]
Abstract
Various models on membrane structure and organization of proteins and complexes in natural membranes emerged during the last years. However, the lack of systematic dynamical studies to complement structural investigations hindered the establishment of a more complete picture of these systems. Elastic incoherent neutron scattering gives access to the dynamics on a molecular level and was applied to natural membranes extracted from the hyperthermophile Aquifex aeolicus and the mesophile Wolinella succinogenes bacteria. The results permitted to extract a hierarchy of dynamic flexibility and atomic resilience within the samples, which correlated with the organization of proteins in bioenergetics complexes and the functionality of the membranes.
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Affiliation(s)
- J Peters
- Institut Laue Langevin, 6 rue J. Horowitz, BP 156, F-38042 Grenoble Cedex 9, France.
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14
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Busheva M, Tzonova I, Stoitchkova K, Andreeva A. Heat-induced reorganization of the structure of photosystem II membranes: Role of oxygen evolving complex. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2012; 117:214-21. [DOI: 10.1016/j.jphotobiol.2012.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 10/04/2012] [Accepted: 10/12/2012] [Indexed: 10/27/2022]
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Pieper J, Trapp M, Skomorokhov A, Natkaniec I, Peters J, Renger G. Temperature-dependent vibrational and conformational dynamics of photosystem II membrane fragments from spinach investigated by elastic and inelastic neutron scattering. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1213-9. [PMID: 22465855 DOI: 10.1016/j.bbabio.2012.03.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 03/07/2012] [Accepted: 03/16/2012] [Indexed: 11/27/2022]
Abstract
Vibrational and conformational protein dynamics of photosystem II (PS II) membrane fragments from spinach were investigated by elastic and inelastic incoherent neutron scattering (EINS and IINS). As to the EINS experiments, the average atomic mean square displacement values of PS II membrane fragments hydrated at a relative humidity of 57% exhibit a dynamical transition at ~230K. In contrast, the dynamical transition was absent at a relative humidity of 44%. These findings are in agreement with previous studies which reported a "freezing" of protein mobility due to dehydration (Pieper et al. (2008) Eur. Biophys. J. 37: 657-663) and its correlation with an inhibition of electron transfer from Q(A)(-) to Q(B) (Kaminskaya et al. (2003) Biochemistry 42, 8119-8132). IINS spectra of a sample hydrated at a relative humidity of 57% show a distinct Boson peak at ~7.5meV at 20K, which shifts towards lower energy values upon temperature increase to 250K. This unexpected effect is interpreted in terms of a "softening" of the protein matrix along with the onset of conformational protein dynamics as revealed by the EINS experiments. Information on the density of vibrational states of pigment-protein complexes is important for a realistic calculation of excitation energy transfer kinetics and spectral lineshapes and is often routinely obtained by optical line-narrowing spectroscopy at liquid helium temperature. The data presented here demonstrate that IINS is a valuable experimental tool in determining the density of vibrational states not only at cryogenic, but also at nearly physiological temperatures up to 250K. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.
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Affiliation(s)
- Jörg Pieper
- Institute of Physics, University of Tartu, Tartu, Estonia.
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