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Chua YZ, Zorn R, Schmelzer JWP, Schick C, Holderer O, Zamponi M. Determination of Cooperativity Length in a Glass-Forming Polymer. ACS Phys Chem Au 2023; 3:172-180. [PMID: 36968449 PMCID: PMC10037462 DOI: 10.1021/acsphyschemau.2c00057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/14/2022] [Accepted: 12/14/2022] [Indexed: 01/05/2023]
Abstract
To describe the properties of glass-forming liquids, the concepts of a cooperativity length or the size of cooperatively rearranging regions are widely employed. Their knowledge is of outstanding importance for the understanding of both thermodynamic and kinetic properties of the systems under consideration and the mechanisms of crystallization processes. By this reason, methods of experimental determination of this quantity are of outstanding importance. Proceeding in this direction, we determine the so-called cooperativity number and, based on it, the cooperativity length by experimental measurements utilizing AC calorimetry and quasi-elastic neutron scattering (QENS) at comparable times. The results obtained are different in dependence on whether temperature fluctuations in the considered nanoscale subsystems are either accounted for or neglected in the theoretical treatment. It is still an open question, which of these mutually exclusive approaches is the correct one. As shown in the present paper on the example of poly(ethyl methacrylate) (PEMA), the cooperative length of about 1 nm at 400 K and a characteristic time of ca. 2 μs determined from QENS coincide most consistently with the cooperativity length determined from AC calorimetry measurements if the effect of temperature fluctuations is incorporated in the description. This conclusion indicates that-accounting for temperature fluctuations-the characteristic length can be derived by thermodynamic considerations from the specific parameters of the liquid at the glass transition and that temperature does fluctuate in small subsystems.
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Affiliation(s)
- Yeong Zen Chua
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051Rostock, Germany
- Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051Rostock, Germany
| | - Reiner Zorn
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Biological Information Processing (IBI-8), 52425Jülich, Germany
| | - Jürn W. P. Schmelzer
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051Rostock, Germany
- Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051Rostock, Germany
| | - Christoph Schick
- Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051Rostock, Germany
- Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051Rostock, Germany
| | - Olaf Holderer
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Garching85748, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Garching85748, Germany
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2
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Kolmangadi MA, Szymoniak P, Zorn R, Böhning M, Wolf M, Zamponi M, Schönhals A. Molecular mobility in high‐performance polynorbornenes: A combined broadband dielectric, advanced calorimetry, and neutron scattering investigation*. POLYM ENG SCI 2022. [DOI: 10.1002/pen.25995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
| | - Paulina Szymoniak
- Bundesanstalt für Materialforschung und ‐prüfung (BAM) Berlin Germany
| | - Reiner Zorn
- Forschungszentrum Jülich GmbH Jülich Centre for Neutron Science (JCNS‐1) and Institute for Biological Information Processing (IBI‐8) Jülich Germany
| | - Martin Böhning
- Bundesanstalt für Materialforschung und ‐prüfung (BAM) Berlin Germany
| | - Marcell Wolf
- Heinz Maier‐Leibnitz Zentrum (MLZ) Technische Universität München Garching Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH Jülich Centre for Neutron Science at MLZ Garching Germany
| | - Andreas Schönhals
- Bundesanstalt für Materialforschung und ‐prüfung (BAM) Berlin Germany
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3
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Rosi BP, D’Angelo A, Buratti E, Zanatta M, Tavagnacco L, Natali F, Zamponi M, Noferini D, Corezzi S, Zaccarelli E, Comez L, Sacchetti F, Paciaroni A, Petrillo C, Orecchini A. Impact of the Environment on the PNIPAM Dynamical Transition Probed by Elastic Neutron Scattering. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Benedetta P. Rosi
- Dipartimento di Fisica e Geologia, Università di Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy
| | - Arianna D’Angelo
- Laboratoire de Physique des Solides, CNRS, Université Paris-Saclay, 510 Rue André Rivière, 91405 Orsay, France
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble, Cedex 9, France
| | - Elena Buratti
- Dipartimento di Fisica, CNR-ISC c/o Università di Roma La Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Marco Zanatta
- Dipartimento di Fisica, Università di Trento, via Sommarive 14, 38123 Trento, Italy
| | - Letizia Tavagnacco
- Dipartimento di Fisica, CNR-ISC c/o Università di Roma La Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Francesca Natali
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble, Cedex 9, France
- CNR-IOM, OGG, 71 Avenue des Martyrs, 38043 Grenoble, Cedex 9, France
| | - Michaela Zamponi
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Daria Noferini
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstrasse 1, 85747 Garching, Germany
- European Spallation Source ERIC, Box 176, 221 00 Lund, Sweden
| | - Silvia Corezzi
- Dipartimento di Fisica e Geologia, Università di Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy
| | - Emanuela Zaccarelli
- Dipartimento di Fisica, CNR-ISC c/o Università di Roma La Sapienza, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Lucia Comez
- Dipartimento di Fisica e Geologia, CNR-IOM c/o Università di Perugia, via Alessandro Pascoli, 06123 Perugia, Italy
| | - Francesco Sacchetti
- Dipartimento di Fisica e Geologia, Università di Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy
| | - Alessandro Paciaroni
- Dipartimento di Fisica e Geologia, Università di Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy
| | - Caterina Petrillo
- Dipartimento di Fisica e Geologia, Università di Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy
| | - Andrea Orecchini
- Dipartimento di Fisica e Geologia, Università di Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy
- Dipartimento di Fisica e Geologia, CNR-IOM c/o Università di Perugia, via Alessandro Pascoli, 06123 Perugia, Italy
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4
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Sharma A, Kruteva M, Zamponi M, Ehlert S, Richter DO, Förster S. Quasielastic neutron scattering reveals the temperature dependent rotational dynamics of densely grafted oleic acid.. J Chem Phys 2022; 156:164908. [DOI: 10.1063/5.0089874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We study the dynamics of pure oleic acid as well as grafted oleic acid synthesized by decomposing iron oleate into oleic acid grafted iron oxide nanoparticles. Our quasielastic neutron scattering study shows that oleic acid dominantly performs translational diffusion at room temperature. On the other hand, in nanocomposites the constraints imposed by grafting and crowding of neighbouring chains restrict the grafted oleic acid to uniaxial rotation. Interestingly, it also manifests mobility in grafted oleic acid below the crystallization temperature of pure oleic acid. The data from grafted oleic acid could be effectively described using uniaxial rotational diffusion model with an additional elastic scattering contribution. This kind of elastic scattering arises due to the restricted bond mobility and increases with decreasing temperature. The radius of rotation obtained from the fitted data agrees very well with the geometry of the molecule and grafting density. These results open possibilities of research on the confined surfactant systems, which could be analysed using the approach described here.
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Affiliation(s)
- Aakash Sharma
- Forschungszentrum Julich GmbH Julich Centre for Neutron Science, Germany
| | | | | | - Sascha Ehlert
- Forschungszentrum Jülich GmbH Jülich Centre for Neutron Science, Germany
| | | | - Stephan Förster
- Forschungszentrum Julich GmbH Julich Centre for Neutron Science, Germany
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5
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Schönhals A, Szymoniak P, Kolmangadi MA, Böhning M, Zamponi M, Frick B, Appel M, Günther G, Russina M, Alentiev DA, Bermeshev M, Zorn R. Microscopic dynamics of highly permeable super glassy polynorbornenes revealed by quasielastic neutron scattering. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2021.119972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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Kruteva M, Zamponi M, Hoffmann I, Allgaier J, Monkenbusch M, Richter D. Non-Gaussian and Cooperative Dynamics of Entanglement Strands in Polymer Melts. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01859] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Margarita Kruteva
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1: Neutron Scattering and Biological Matter), 52425 Jülich, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstraße 1, 85748 Garching, Germany
| | - Ingo Hoffmann
- Institut Laue-Langevin (ILL), B.P. 156, F-38042 Grenoble Cedex 9, France
| | - Jürgen Allgaier
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1: Neutron Scattering and Biological Matter), 52425 Jülich, Germany
| | - Michael Monkenbusch
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1: Neutron Scattering and Biological Matter), 52425 Jülich, Germany
| | - Dieter Richter
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1: Neutron Scattering and Biological Matter), 52425 Jülich, Germany
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7
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Nakagawa H, Appavou MS, Wuttke J, Zamponi M, Holderer O, Schrader TE, Richter D, Doster W. Nanosecond structural dynamics of intrinsically disordered β-casein micelles by neutron spectroscopy. Biophys J 2021; 120:5408-5420. [PMID: 34717964 PMCID: PMC8715185 DOI: 10.1016/j.bpj.2021.10.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 09/17/2021] [Accepted: 10/13/2021] [Indexed: 10/20/2022] Open
Abstract
β-casein undergoes a reversible endothermic self-association, forming protein micelles of limited size. In its functional state, a single β-casein monomer is unfolded, which creates a high structural flexibility, which is supposed to play a major role in preventing the precipitation of calcium phosphate particles. We characterize the structural flexibility in terms of nanosecond molecular motions, depending on the temperature by quasielastic neutron scattering. Our major questions are: Does the self-association reduce the chain flexibility? How does the dynamic spectrum of disordered caseins differ from a compactly globular protein? How does the dynamic spectrum of β-casein in solution differ from that of a protein in hydrated powder states? We report on two relaxation processes on a nanosecond and a sub-nanosecond timescale for β-casein in solution. Both processes are analyzed by Brownian oscillator model, by which the spring constant can be defined in the isotropic parabolic potential. The slower process, which is analyzed by neutron spin echo, seems a characteristic feature of the unfolded structure. It requires bulk solvent and is not seen in hydrated protein powders. The faster process, which is analyzed by neutron backscattering, has a smaller amplitude and requires hydration water, which is also observed with folded proteins in the hydrated state. The self-association had no significant influence on internal relaxation, and thus, a β-casein protein monomer flexibility is preserved in the micelle. We derive spring constants of the faster and slower motions of β-caseins in solution and compared them with those of some proteins in various states (folded or hydrated powder).
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Affiliation(s)
- Hiroshi Nakagawa
- Materials Sciences Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki, Japan; Forschungszentrum Jülich, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany; J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki, Japan.
| | - Marie-Sousai Appavou
- Forschungszentrum Jülich, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany
| | - Joachim Wuttke
- Forschungszentrum Jülich, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany
| | - Olaf Holderer
- Forschungszentrum Jülich, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany
| | - Tobias E Schrader
- Forschungszentrum Jülich, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany
| | - Dieter Richter
- Forschungszentrum Jülich, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany
| | - Wolfgang Doster
- Technische Universität München, Physik-Department, Garching, Germany
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8
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Jhalaria M, Huang Y, Ruzicka E, Tyagi M, Zorn R, Zamponi M, García Sakai V, Benicewicz B, Kumar S. Activated Transport in Polymer Grafted Nanoparticle Melts. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mayank Jhalaria
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
| | - Yucheng Huang
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Eric Ruzicka
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Madhusudan Tyagi
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United States
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Reiner Zorn
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Biological Information Processing (IBI-8), 52425 Jülich, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstr. 1 85748 Garching, Germany
| | - Victoria García Sakai
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, UK
| | - Brian Benicewicz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Sanat Kumar
- Department of Chemical Engineering, Columbia University, New York, New York 10027, United States
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9
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Abstract
Polymer-solvent interactions play a crucial role in the stimuli-responsive behaviour of polymer networks. They influence the swelling/deswelling behaviour as well as the dynamics of the polymer chains. Scattering experiments provide insight into the polymer-water interaction of poly(N-isopropylacrylamide) (PNIPAM) microgels cross-linked with N,N'-methylenebisacrylamide (BIS) in dried and humidified state. The water mobility is studied by means of neutron spin-echo spectroscopy and neutron backscattering spectroscopy. The residual water amount has been determined with Karl Fischer titration. For both degrees of humidification, the relaxation time of the water molecules is much larger than that of free water due to the strong interactions with the polymer network and is only weakly depending on temperature and length scale of observation. The possible influence of the water on methyl group rotations is discussed.
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Affiliation(s)
- Tetyana Kyrey
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany.
| | - Judith Witte
- Technical University Berlin, Institute of Chemistry, Berlin, Germany
| | - Jana Lutzki
- Technical University Berlin, Institute of Chemistry, Berlin, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany.
| | - Stefan Wellert
- Technical University Berlin, Institute of Chemistry, Berlin, Germany
| | - Olaf Holderer
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany.
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10
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Zamponi M, Kruteva M, Monkenbusch M, Willner L, Wischnewski A, Hoffmann I, Richter D. Cooperative Chain Dynamics of Tracer Chains in Highly Entangled Polyethylene Melts. Phys Rev Lett 2021; 126:187801. [PMID: 34018790 DOI: 10.1103/physrevlett.126.187801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
By neutron spin echo spectroscopy, we have studied the center of mass motion of short tracer chains on the molecular length scale within a highly entangled polymer matrix. The center of mass mean square displacements of the tracers independent of their molecular weight is subdiffusive at short times until it has reached the size of the tube d; then, a crossover to Fickian diffusion takes place. This observation cannot be understood within the tube model of reptation, but is rationalized as a result of important interchain couplings that lead to cooperative chain motion within the entanglement volume ∼d^{3}. Thus, the cooperative tracer chain motions are limited by the tube size d. If the center of mass displacement exceeds this size, uncorrelated Fickian diffusion takes over. Compared to the prediction of the Rouse model we observe a significantly reduced contribution of the tracer's internal modes to the spectra corroborating the finding of cooperative rather than Rouse dynamics within d^{3}.
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Affiliation(s)
- M Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstraße 1, 85748 Garching, Germany
| | - M Kruteva
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany
| | - M Monkenbusch
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany
| | - L Willner
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany
| | - A Wischnewski
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany
| | - I Hoffmann
- Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, 38000 Grenoble, France
| | - D Richter
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany
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11
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Schirò G, Fichou Y, Brogan APS, Sessions R, Lohstroh W, Zamponi M, Schneider GJ, Gallat FX, Paciaroni A, Tobias DJ, Perriman A, Weik M. Diffusivelike Motions in a Solvent-Free Protein-Polymer Hybrid. Phys Rev Lett 2021; 126:088102. [PMID: 33709739 DOI: 10.1103/physrevlett.126.088102] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 01/11/2021] [Indexed: 05/16/2023]
Abstract
The interaction between proteins and hydration water stabilizes protein structure and promotes functional dynamics, with water translational motions enabling protein flexibility. Engineered solvent-free protein-polymer hybrids have been shown to preserve protein structure, function, and dynamics. Here, we used neutron scattering, protein and polymer perdeuteration, and molecular dynamics simulations to explore how a polymer dynamically replaces water. Even though relaxation rates and vibrational properties are strongly modified in polymer coated compared to hydrated proteins, liquidlike polymer dynamics appear to plasticize the conjugated protein in a qualitatively similar way as do hydration-water translational motions.
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Affiliation(s)
- Giorgio Schirò
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000 Grenoble, France
| | - Yann Fichou
- CNRS, Chemistry and Biology of Membranes and Nanoobjects (CBMN) UMR 5348, Institut Europeen de Chimie et Biologie (IECB), University of Bordeaux, 33600 Pessac, France
| | - Alex P S Brogan
- School of Biochemistry, Medical Sciences Building, University Walk, Bristol BS8 1TD, United Kingdom
| | - Richard Sessions
- Department of Chemistry, King's College London, Britannia House, London SE1 1DB, United Kingdom
| | - Wiebke Lohstroh
- Heinz Maier-Leibnitz Zentrum, Technische Universität München, Garching, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Garching, Germany
| | - Gerald J Schneider
- Department of Chemistry and Department of Physics & Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - François-Xavier Gallat
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000 Grenoble, France
| | - Alessandro Paciaroni
- Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Douglas J Tobias
- Department of Chemistry, University of California, Irvine, California, CA 92697, USA
| | - Adam Perriman
- School of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TL, United Kingdom
| | - Martin Weik
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000 Grenoble, France
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12
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Pounot K, Grime GW, Longo A, Zamponi M, Noferini D, Cristiglio V, Seydel T, Garman EF, Weik M, Foderà V, Schirò G. Zinc determines dynamical properties and aggregation kinetics of human insulin. Biophys J 2021; 120:886-898. [PMID: 33545104 DOI: 10.1016/j.bpj.2020.11.2280] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 11/08/2020] [Accepted: 11/30/2020] [Indexed: 12/26/2022] Open
Abstract
Protein aggregation is a widespread process leading to deleterious consequences in the organism, with amyloid aggregates being important not only in biology but also for drug design and biomaterial production. Insulin is a protein largely used in diabetes treatment, and its amyloid aggregation is at the basis of the so-called insulin-derived amyloidosis. Here, we uncover the major role of zinc in both insulin dynamics and aggregation kinetics at low pH, in which the formation of different amyloid superstructures (fibrils and spherulites) can be thermally induced. Amyloid aggregation is accompanied by zinc release and the suppression of water-sustained insulin dynamics, as shown by particle-induced x-ray emission and x-ray absorption spectroscopy and by neutron spectroscopy, respectively. Our study shows that zinc binding stabilizes the native form of insulin by facilitating hydration of this hydrophobic protein and suggests that introducing new binding sites for zinc can improve insulin stability and tune its aggregation propensity.
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Affiliation(s)
- Kevin Pounot
- Applied Physics, University of Tübingen, Tübingen, Baden-Würtemberg, Germany.
| | | | - Alessandro Longo
- Istituto per lo Studio dei Materiali Nanostrutturati, CNR, Palermo, Italy
| | - Michaela Zamponi
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH Outstation at MLZ, Garching, Germany
| | - Daria Noferini
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH Outstation at MLZ, Garching, Germany
| | | | - Tilo Seydel
- Science Division, Institut Max von Laue-Paul Langevin, Grenoble, France
| | | | - Martin Weik
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000 Grenoble, France
| | - Vito Foderà
- Pharmacy, University of Copenhagen, Copenhagen, Denmark.
| | - Giorgio Schirò
- Université Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000 Grenoble, France.
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13
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Zorn R, Lohstroh W, Zamponi M, Harrison WJ, Budd PM, Böhning M, Schönhals A. Molecular Mobility of a Polymer of Intrinsic Microporosity Revealed by Quasielastic Neutron Scattering. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c00963] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Reiner Zorn
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1), Jülich 52425,Germany
| | - Wiebke Lohstroh
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstraße 1, Garching 85748, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstr. 1, Garching 85748, Germany
| | - Wayne J. Harrison
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Peter M. Budd
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Martin Böhning
- BAM Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 87, Berlin 12205, Germany
| | - Andreas Schönhals
- BAM Bundesanstalt für Materialforschung und -prüfung, Unter den Eichen 87, Berlin 12205, Germany
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14
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Kämpf K, Demuth D, Zamponi M, Wuttke J, Vogel M. Quasielastic neutron scattering studies on couplings of protein and water dynamics in hydrated elastin. J Chem Phys 2020; 152:245101. [PMID: 32610976 DOI: 10.1063/5.0011107] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Performing quasielastic neutron scattering measurements and analyzing both elastic and quasielasic contributions, we study protein and water dynamics of hydrated elastin. At low temperatures, hydration-independent methyl group rotation dominates the findings. It is characterized by a Gaussian distribution of activation energies centered at about Em = 0.17 eV. At ∼195 K, coupled protein-water motion sets in. The hydration water shows diffusive motion, which is described by a Gaussian distribution of activation energies with Em = 0.57 eV. This Arrhenius behavior of water diffusion is consistent with previous results for water reorientation, but at variance with a fragile-to-strong crossover at ∼225 K. The hydration-related elastin backbone motion is localized and can be attributed to the cage rattling motion. We speculate that its onset at ∼195 K is related to a secondary glass transition, which occurs when a β relaxation of the protein has a correlation time of τβ ∼ 100 s. Moreover, we show that its temperature-dependent amplitude has a crossover at the regular glass transition Tg = 320 K of hydrated elastin, where the α relaxation of the protein obeys τα ∼ 100 s. By contrast, we do not observe a protein dynamical transition when water dynamics enters the experimental time window at ∼240 K.
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Affiliation(s)
- Kerstin Kämpf
- Institute of Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 6, 64289 Darmstadt, Germany
| | - Dominik Demuth
- Institute of Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 6, 64289 Darmstadt, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, 85747 Garching, Germany
| | - Joachim Wuttke
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Lichtenbergstraße 1, 85747 Garching, Germany
| | - Michael Vogel
- Institute of Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 6, 64289 Darmstadt, Germany
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15
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Mhanna R, Catrou P, Dutta S, Lefort R, Essafri I, Ghoufi A, Muthmann M, Zamponi M, Frick B, Morineau D. Dynamic Heterogeneities in Liquid Mixtures Confined in Nanopores. J Phys Chem B 2020; 124:3152-3162. [DOI: 10.1021/acs.jpcb.0c01035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ramona Mhanna
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
- Institut Laue-Langevin, 71 avenue des Martyrs, F-38000 Grenoble, France
| | - Pierre Catrou
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Sujeet Dutta
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Ronan Lefort
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Ilham Essafri
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Aziz Ghoufi
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
| | - Matthias Muthmann
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ Lichtenbergstrasse 1, 85748 Garching, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ Lichtenbergstrasse 1, 85748 Garching, Germany
| | - Bernhard Frick
- Institut Laue-Langevin, 71 avenue des Martyrs, F-38000 Grenoble, France
| | - Denis Morineau
- Institute of Physics of Rennes, CNRS−University of Rennes 1, UMR 6251, F-35042 Rennes, France
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16
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Yildirim A, Krause C, Zorn R, Lohstroh W, Schneider GJ, Zamponi M, Holderer O, Frick B, Schönhals A. Complex molecular dynamics of a symmetric model discotic liquid crystal revealed by broadband dielectric, thermal and neutron spectroscopy. Soft Matter 2020; 16:2005-2016. [PMID: 32003764 DOI: 10.1039/c9sm02487e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The molecular dynamics of the triphenylene-based discotic liquid crystal HAT6 is investigated by broadband dielectric spectroscopy, advanced dynamical calorimetry and neutron scattering. Differential scanning calorimetry in combination with X-ray scattering reveals that HAT6 has a plastic crystalline phase at low temperatures, a hexagonally ordered liquid crystalline phase at higher temperatures and undergoes a clearing transition at even higher temperatures. The dielectric spectra show several relaxation processes: a localized γ-relaxation at lower temperatures and a so called α2-relaxation at higher temperatures. The relaxation rates of the α2-relaxation have a complex temperature dependence and bear similarities to a dynamic glass transition. The relaxation rates estimated by Hyper DSC, Fast Scanning calorimetry and AC Chip calorimetry have a different temperature dependence than the dielectric α2-relaxation and follow the VFT-behavior characteristic for glassy dynamics. Therefore, this process is called α1-relaxation. Its relaxation rates show a similarity with that of polyethylene. For this reason, the α1-relaxation is assigned to the dynamic glass transition of the alkyl chains in the intercolumnar space. Moreover, this process is not observed by dielectric spectroscopy, which supports its assignment. The α2-relaxation is assigned to small scale translatorial and/or small angle fluctuations of the cores. The neutron scattering data reveal two relaxation processes. The process observed at shorter relaxation times is assigned to the methyl group rotation. The second relaxation process at longer time scales agree in the temperature dependence of its relaxation rates with that of the dielectric γ-relaxation.
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Affiliation(s)
- Arda Yildirim
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
| | - Christina Krause
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
| | - Reiner Zorn
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany
| | - Wiebke Lohstroh
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstraße 1, 85748 Garching, Germany
| | - Gerald J Schneider
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstr. 1, 85748 Garching, Germany
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstr. 1, 85748 Garching, Germany
| | - Olaf Holderer
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstr. 1, 85748 Garching, Germany
| | - Bernhard Frick
- Institut Laue-Langevin, 71 avenue des Martyrs, 38042 Grenoble Cedex 9, France
| | - Andreas Schönhals
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
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17
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Monkenbusch M, Kruteva M, Zamponi M, Willner L, Hoffman I, Farago B, Richter D. A practical method to account for random phase approximation effects on the dynamic scattering of multi-component polymer systems. J Chem Phys 2020; 152:054901. [PMID: 32035437 DOI: 10.1063/1.5139712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Investigations of polymer systems that rely on the interpretation of dynamical scattering results as, e.g., the structure factor S(Q, t) of single chains or chain sections may require the inclusion of effects, as described within the framework of the random phase approximation (RPA) for polymers. To do this in practice for the dynamic part of S(Q, t) beyond the initial slope is a challenge. Here, we present a method (and software) that allows a straightforward assessment of dynamical RPA effects and inclusion of these in the process/procedures of model fitting. Examples of applications to the interpretation of neutron spin-echo data multi-component polymer melts are shown.
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Affiliation(s)
- M Monkenbusch
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany
| | - M Kruteva
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany
| | - M Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstr. 1, 85748 Garching, Germany
| | - L Willner
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany
| | - I Hoffman
- Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, 38000 Grenoble, France
| | - B Farago
- Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, 38000 Grenoble, France
| | - D Richter
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), 52425 Jülich, Germany
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18
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Stadler AM, Schneidewind J, Zamponi M, Knieps-Grünhagen E, Gholami S, Schwaneberg U, Rivalta I, Garavelli M, Davari M, Jaeger KE, Krause F, Bocola M, Krauss U. Activation of a Photoenzyme Results in Modified Structure and Dynamics. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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19
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Rok M, Moskwa M, Dopieralski P, Medycki W, Zamponi M, Bator G. The influence of structure on the methyl group dynamics of polymorphic complexes: 6,6′-dimethyl-2,2′-dipyridyl with halo derivatives of benzoquinone acids. CrystEngComm 2020. [DOI: 10.1039/d0ce00973c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The structural analysis, neutron scattering, 1H NMR and computational methods combined to investigate new molecular complexes.
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Affiliation(s)
- Magdalena Rok
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | - Marcin Moskwa
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | | | - Wojciech Medycki
- Institute of Molecular Physics
- Polish Academy of Sciences
- 60-179 Poznań
- Poland
| | - Michaela Zamponi
- Forschungszentrum Jülich GmbH
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ)
- 85748 Garching
- Germany
| | - Grażyna Bator
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
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20
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Sarter M, Niether D, Koenig BW, Lohstroh W, Zamponi M, Jalarvo NH, Wiegand S, Fitter J, Stadler AM. Strong Adverse Contribution of Conformational Dynamics to Streptavidin-Biotin Binding. J Phys Chem B 2019; 124:324-335. [PMID: 31710813 DOI: 10.1021/acs.jpcb.9b08467] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Molecular dynamics plays an important role for the biological function of proteins. For protein ligand interactions, changes of conformational entropy of protein and hydration layer are relevant for the binding process. Quasielastic neutron scattering (QENS) was used to investigate differences in protein dynamics and conformational entropy of ligand-bound and ligand-free streptavidin. Protein dynamics were probed both on the fast picosecond time scale using neutron time-of-flight spectroscopy and on the slower nanosecond time scale using high-resolution neutron backscattering spectroscopy. We found the internal equilibrium motions of streptavidin and the corresponding mean square displacements (MSDs) to be greatly reduced upon biotin binding. On the basis of the observed MSDs, we calculated the difference of conformational entropy ΔSconf of the protein component between ligand-bound and ligand-free streptavidin. The rather large negative ΔSconf value (-2 kJ mol-1 K-1 on the nanosecond time scale) obtained for the streptavidin tetramer seems to be counterintuitive, given the exceptionally high affinity of streptavidin-biotin binding. Literature data on the total entropy change ΔS observed upon biotin binding to streptavidin, which includes contributions from both the protein and the hydration water, suggest partial compensation of the unfavorable ΔSconf by a large positive entropy gain of the surrounding hydration layer and water molecules that are displaced during ligand binding.
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Affiliation(s)
- Mona Sarter
- I. Physikalisches Institut (IA), AG Biophysik , RWTH Aachen , Sommerfeldstrasse 14 , Aachen D-52074 , Germany
| | | | | | - Wiebke Lohstroh
- Heinz Maier-Leibnitz Zentrum , Technische Universität München , Garching D-85747 , Germany
| | - Michaela Zamponi
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ) , Forschungszentrum Jülich GmbH , Lichtenbergstrasse 1 , Garching D-85748 , Germany
| | - Niina H Jalarvo
- Neutron Scattering Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831-6475 , United States
| | - Simone Wiegand
- Department für Chemie - Physikalische Chemie , Universität zu Köln , Cologne D-50939 , Germany
| | - Jörg Fitter
- I. Physikalisches Institut (IA), AG Biophysik , RWTH Aachen , Sommerfeldstrasse 14 , Aachen D-52074 , Germany.,Institute of Complex Systems, Molecular Biophysics (ICS-5) , Forschungszentrum Jülich GmbH , Jülich D-52428 , Germany
| | - Andreas M Stadler
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , Aachen D-52056 , Germany
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21
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Jhalaria M, Buenning E, Huang Y, Tyagi M, Zorn R, Zamponi M, García-Sakai V, Jestin J, Benicewicz BC, Kumar SK. Accelerated Local Dynamics in Matrix-Free Polymer Grafted Nanoparticles. Phys Rev Lett 2019; 123:158003. [PMID: 31702322 DOI: 10.1103/physrevlett.123.158003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/26/2019] [Indexed: 06/10/2023]
Abstract
The tracer diffusion coefficient of six different permanent gases in polymer-grafted nanoparticle (GNP) membranes, i.e., neat GNP constructs with no solvent, show a maximum as a function of the grafted chain length at fixed grafting density. This trend is reproduced for two different NP sizes and three different polymer chemistries. We postulate that nonmonotonic changes in local, segmental friction as a function of graft chain length (at fixed grafting density) must underpin these effects, and use quasielastic neutron scattering to probe the self-motions of polymer chains at the relevant segmental scale (i.e., sampling local friction or viscosity). These data, when interpreted with a jump diffusion model, show that, in addition to the speeding-up in local chain dynamics, the elementary distance over which segments hop is strongly dependent on graft chain length. We therefore conclude that transport modifications in these GNP layers, which are underpinned by a structural transition from a concentrated brush to semidilute polymer brush, are a consequence of both spatial and temporal changes, both of which are likely driven by the lower polymer densities of the GNPs relative to the neat polymer.
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Affiliation(s)
- Mayank Jhalaria
- Department of Chemical Engineering, Columbia University, New York, New York 10027, USA
| | - Eileen Buenning
- Department of Chemical Engineering, Columbia University, New York, New York 10027, USA
| | - Yucheng Huang
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29201, USA
| | - Madhusudan Tyagi
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, USA
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Reiner Zorn
- Jülich Centre for Neutron Science (JCNS-1) and Institute for Complex Systems (ICS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Michaela Zamponi
- Jülich Centre for Neutron Science at MLZ, Forschungszentrum Jülich GmbH, Lichtenbergstrasse 1, 85748 Garching, Germany
| | - Victoria García-Sakai
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, United Kingdom
| | - Jacques Jestin
- CEA Saclay, Laboratoire Léon Brillouin, F-91191 Gif Sur Yvette, France
| | - Brian C Benicewicz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29201, USA
| | - Sanat K Kumar
- Department of Chemical Engineering, Columbia University, New York, New York 10027, USA
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22
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Melchior JP, Lohstroh W, Zamponi M, Jalarvo NH. Multiscale water dynamics in model Anion Exchange Membranes for Alkaline Membrane Fuel Cells. J Memb Sci 2019. [DOI: 10.1016/j.memsci.2019.05.079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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23
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Stadler AM, Schneidewind J, Zamponi M, Knieps-Grünhagen E, Gholami S, Schwaneberg U, Rivalta I, Garavelli M, Davari MD, Jaeger KE, Krauss U. Ternary Complex Formation and Photoactivation of a Photoenzyme Results in Altered Protein Dynamics. J Phys Chem B 2019; 123:7372-7384. [PMID: 31380636 DOI: 10.1021/acs.jpcb.9b06608] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The interplay between protein dynamics and catalysis remains a fundamental question in enzymology. We here investigate the ns-timescale dynamics of a light-dependent NADPH:protochlorophyllide oxidoreductase (LPOR), a photoenzyme crucial for chlorophyll synthesis. LPORs catalyze the light-triggered trans addition of a hydride and a proton across the C17═C18 double bond of the chlorophyll precursor protochlorophyllide (Pchlide). Because of the lack of an LPOR structure, the global structural and dynamic consequences of LPOR/Pchlide/NADPH ternary complex formation remain elusive. Moreover, photoactivation of LPORs by low-light preillumination is controversially discussed as unequivocal proof for this phenomenon is lacking. By employing quasielastic neutron spectroscopy (QENS), we show that the formation of the ternary holoprotein complex as well as photoactivation lead to progressive rigidification of the protein. These findings are supported by thermostability measurements, which reveal different melting behavior and thermostabilities for the apo- and holoprotein ternary complexes. Molecular dynamics simulations in good agreement with the experimental QENS results suggest that the increased flexibility observed for the apoprotein stems from structural fluctuations of the NADPH and Pchlide substrate binding sites of the enzyme. On the basis of our results, in conjunction with activity and stability measurements, we provide independent proof for LPOR photoactivation, defined as a process that modifies the protein structure and dynamics, resulting in an increased substrate turnover. Our findings advance the structural and dynamic understanding of LPORs and provide a first link between protein dynamics and catalysis for this enzyme class.
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Affiliation(s)
| | | | - Michaela Zamponi
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ) , Forschungszentrum Jülich GmbH , Lichtenbergstr. 1 , 85748 Garching , Germany
| | | | - Samira Gholami
- Dipartimento di Chimica Industriale , Università degli Studi di Bologna , Viale del Risorgimento 4 , I-40136 Bologna , Italy
| | - Ulrich Schwaneberg
- Institute of Biotechnology , RWTH Aachen University , Worringer Weg 3 , D-52074 Aachen , Germany.,DWI-Leibniz Institute for Interactive Materials , Forckenbeckstraße 50 , 52056 Aachen , Germany
| | - Ivan Rivalta
- Université de Lyon, École Normale Supérieure de Lyon, CNRS, Université Claude Bernard Lyon 1, Laboratoire de Chimie UMR 5182 , F-69342 Lyon , France
| | - Marco Garavelli
- Dipartimento di Chimica Industriale , Università degli Studi di Bologna , Viale del Risorgimento 4 , I-40136 Bologna , Italy.,École Normale Supérieure de Lyon, CNRS, Laboratoire de Chimie UMR 5182, Université de Lyon , 46 Allée d'Italie , F-69364 Lyon Cedex 07 , France
| | - Mehdi D Davari
- Institute of Biotechnology , RWTH Aachen University , Worringer Weg 3 , D-52074 Aachen , Germany
| | - Karl-Erich Jaeger
- IBG-1: Biotechnologie , Forschungszentrum Jülich GmbH , D-52425 Jülich , Germany
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24
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Rok M, Bator G, Zarychta B, Dziuk B, Repeć J, Medycki W, Zamponi M, Usevičius G, Šimėnas M, Banys J. Isostructural phase transition, quasielastic neutron scattering and magnetic resonance studies of a bistable dielectric ion-pair crystal [(CH 3) 2NH 2] 2KCr(CN) 6. Dalton Trans 2019; 48:4190-4202. [PMID: 30821302 DOI: 10.1039/c8dt05082a] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We have synthesised and characterised a novel organic-inorganic hybrid crystal, [(CH3)2NH2]2KCr(CN)6. The thermal DSC, TMA, DTG and DTA analyses indicate two solid-to-solid structural phase transitions (PTs). According to the X-ray diffraction experiments, the first PT at 220 K is isostructural, since it does not involve a change of the space group. This transition occurs between the states, where the (CH3)2NH2+ cations are orientationally disordered and ordered (frozen). The other reversible PT at 481 K leads to a melt-like phase similar to the one observed in plastic crystals or polar liquids. Dielectric spectroscopy has been used to characterise the switching properties of the dipole moments in the vicinity of the PTs. Continuous-wave electron paramagnetic resonance spectroscopy was employed to investigate the effect of ordering on the local environment of the Cr3+ ions. We have also applied the quasielastic neutron scattering (QENS) technique as well as 1H NMR spectroscopy to measure the dynamics of the (CH3)2NH2+ cations residing in the inorganic framework.
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Affiliation(s)
- M Rok
- Faculty of Chemistry, University of Wroclaw, 14 F. Joliot - Curie, 50-383 Wroclaw, Poland.
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25
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Sarter M, Stadler AM, Niether D, Koenig BW, Zamponi M, Wiebke L, Wiegand S, Fitter J. The Relevance of Conformational Entropy for Protein Ligand Interactions: the Case of Biotin and Streptavidin. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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26
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Chatterji T, Zamponi M, Wuttke J. Hyperfine interaction in cobalt by high-resolution neutron spectroscopy. J Phys Condens Matter 2019; 31:025801. [PMID: 30516135 DOI: 10.1088/1361-648x/aaeead] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We have investigated the ferromagnetic phase transition of elemental Co by high-resolution neutron backscattering spectroscopy. We monitored the splitting of the nuclear levels by the hyperfine field at the Co nucleus. The energy of this hyperfine splitting is identified as the order parameter of the ferromagnetic phase transition. By measuring the temperature dependence of the energy we determined the critical exponent [Formula: see text] and the ferromagnetic Curie temperature of [Formula: see text] K. The present result of the critical exponent agrees better with the predicted value (0.367) of the three-dimensional Heisenberg model than that determined previously by nuclear magnetic resonance.
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Affiliation(s)
- Tapan Chatterji
- Institut Laue-Langevin, B.P. 156, 38042 Grenoble Cedex 9, France
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27
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Zeller D, Telling MTF, Zamponi M, García Sakai V, Peters J. Analysis of elastic incoherent neutron scattering data beyond the Gaussian approximation. J Chem Phys 2018; 149:234908. [PMID: 30579322 DOI: 10.1063/1.5049938] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
This work addresses the use of the Gaussian approximation as a common tool to extract atomic motions in proteins from elastic incoherent neutron scattering and whether improvements in data analysis and additional information can be obtained when going beyond that. We measured alpha-lactalbumin with different levels of hydration on three neutron backscattering spectrometers, to be able to resolve a wide temporal and spatial range for dynamics. We demonstrate that the Gaussian approximation gives qualitatively similar results to models that include heterogeneity, if one respects a certain procedure to treat the intercept of the elastic intensities with the momentum transfer axis. However, the inclusion of motional heterogeneity provides better fits to the data. Our analysis suggests an approach of limited heterogeneity, where including only two kinds of motions appears sufficient to obtain more quantitative results for the mean square displacement. Finally, we note that traditional backscattering spectrometers pose a limit on the lowest accessible momentum transfer. We therefore suggest that complementary information about the spatial evolution of the elastic intensity close to zero momentum transfer can be obtained using other neutron methods, in particular, neutron spin-echo together with polarization analysis.
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Affiliation(s)
- D Zeller
- Université Grenoble Alpes, CNRS, LiPhy, 140 av. de la Physique, 38000 Grenoble, France
| | - M T F Telling
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, United Kingdom
| | - M Zamponi
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstr. 1, 85748 Garching, Germany
| | - V García Sakai
- ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX, United Kingdom
| | - J Peters
- Université Grenoble Alpes, CNRS, LiPhy, 140 av. de la Physique, 38000 Grenoble, France
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28
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Rok M, Bator G, Medycki W, Zamponi M, Balčiūnas S, Šimėnas M, Banys J. Reorientational dynamics of organic cations in perovskite-like coordination polymers. Dalton Trans 2018; 47:17329-17341. [PMID: 30475377 DOI: 10.1039/c8dt03372b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Here we report the dynamics of organic cations as guest molecules in a perovskite host-framework. The molecular motion of CH3NH3+ (MAFe), (CH3)2NH2+ (DMAFe) and (CH3)3NH+ (TrMAFe) in the cage formed by KFe(CN)63- units was studied using a combination of experimental methods: (i) thermal analysis, (ii) dielectric and electric studies, (iii) optical observations, (iv) EPR and 1H NMR spectroscopy and (v) quasielastic neutron scattering (QENS). In the case of MAFe and TrMAFe, the thermal analysis reveals one solid-to-solid phase transition (PT) and two PTs for the DMAFe crystal. A markedly temperature-dependent dielectric constant indicates the tunable and switchable properties of the complexes. Also, their semiconducting properties are confirmed by a dc conductivity measurement. The broadband dielectric relaxation is analyzed for the TrMAFe sample in the frequency range of 100 Hz-1 GHz. QENS shows that we deal rather with the localized motion of the cation than a diffusive one. Three models, which concern the simultaneous rotation of the CH3 and/or NH3 group, π-flips and free rotations of the organic cation, are used to fit the elastic incoherent structure factor. The 1H NMR spin-lattice relaxation time for all compounds under study, as well as the second moments, has been measured in a wide temperature range. In all studied samples, the temperature dependence of the second moment of the proton NMR line indicated the gradual evolution of the molecular movements from the rigid state up to a highly disordered one.
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Affiliation(s)
- M Rok
- Faculty of Chemistry, University of Wroclaw, 14 F. Joliot - Curie, 50-383 Wroclaw, Poland. and Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, 141-980 Dubna, Russia
| | - G Bator
- Faculty of Chemistry, University of Wroclaw, 14 F. Joliot - Curie, 50-383 Wroclaw, Poland.
| | - W Medycki
- Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland
| | - M Zamponi
- Forschungszentrum Jülich GmbH, Juelich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstr. 1, 85748 Garching, Germany
| | - S Balčiūnas
- Faculty of Physics, Vilnius University, Sauletekio av. 9, LT-10222 Vilnius, Lithuania
| | - M Šimėnas
- Faculty of Physics, Vilnius University, Sauletekio av. 9, LT-10222 Vilnius, Lithuania
| | - J Banys
- Faculty of Physics, Vilnius University, Sauletekio av. 9, LT-10222 Vilnius, Lithuania
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29
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Weidner MC, Evenson Z, Zamponi M, Possart W. Molecular Motion in Viscous DGEBA with Nanoparticles as Seen by Quasi-Elastic Neutron Scattering. MACROMOL CHEM PHYS 2018. [DOI: 10.1002/macp.201800275] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | - Zach Evenson
- Heinz Maier-Leibnitz Center; Physics Department; Technical University of Munich; D-85738 Germany
| | - Michaela Zamponi
- Juelich Center for Neutron Science at Heinz Maier-Leibnitz Center; D-85748 Germany
| | - Wulff Possart
- Adhesion and Interphases in Polymers; Saarland University; D-66123 Germany
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30
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Rok M, Bator G, Sawka-Dobrowolska W, Durlak P, Moskwa M, Medycki W, Sobczyk L, Zamponi M. Crystal structural analysis of methyl-substituted pyrazines with anilic acids: a combined diffraction, inelastic neutron scattering,1H-NMR study and theoretical approach. CrystEngComm 2018. [DOI: 10.1039/c8ce00040a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular complexes of the pyrazine derivatives with anilic acids were analyzed in terms of the structure of molecules, the vibrational spectra, INS,1HNMR and theoretical approach.
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Affiliation(s)
- M. Rok
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | - G. Bator
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | | | - P. Durlak
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | - M. Moskwa
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | - W. Medycki
- Institute of Molecular Physics
- Polish Academy of Sciences
- 60-179 Poznań
- Poland
| | - L. Sobczyk
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | - M. Zamponi
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ)
- Forschungszentrum Jülich GmbH
- 85748 Garching
- Germany
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31
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Holler S, Moreno AJ, Zamponi M, Bačová P, Willner L, Iatrou H, Falus P, Richter D. The Role of the Functionality in the Branch Point Motion in Symmetric Star Polymers: A Combined Study by Simulations and Neutron Spin Echo Spectroscopy. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01579] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Stefan Holler
- Forschungszentrum
Jülich GmbH, 52425 Jülich, Germany
- Centro de Física
de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - Angel J. Moreno
- Centro de Física
de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Donostia
International
Physics Center, Paseo Manuel de Lardizabal
4, 20018 San Sebastian, Spain
| | | | - Petra Bačová
- Centro de Física
de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Institute
of Applied and Computational Mathematics (IACM), Foundation for Research and Technology Hellas (FORTH), 71110 Heraklion, Crete Greece
| | - Lutz Willner
- Forschungszentrum
Jülich GmbH, 52425 Jülich, Germany
| | - Hermis Iatrou
- Department
of Chemistry, University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Peter Falus
- Institut Laue-Langevin, 71 Avenue
des Martyrs, CS 20156, Cedex 9 38042 Grenoble, France
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32
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Mark C, Holderer O, Allgaier J, Hübner E, Pyckhout-Hintzen W, Zamponi M, Radulescu A, Feoktystov A, Monkenbusch M, Jalarvo N, Richter D. Polymer Chain Conformation and Dynamical Confinement in a Model One-Component Nanocomposite. Phys Rev Lett 2017; 119:047801. [PMID: 29341730 DOI: 10.1103/physrevlett.119.047801] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Indexed: 06/07/2023]
Abstract
We report a neutron-scattering investigation on the structure and dynamics of a single-component nanocomposite based on SiO_{2} particles that were grafted with polyisoprene chains at the entanglement limit. By skillful labeling, we access both the monomer density in the corona as well as the conformation of the grafted chains. While the corona profile follows a r^{-1} power law, the conformation of a grafted chain is identical to that of a chain in a reference melt, implying a high mutual penetration of the coronas from different particles. The brush crowding leads to topological confinement of the chain dynamics: (i) At local scales, the segmental dynamics is unchanged compared to the reference melt, while (ii) at the scale of the chain, the dynamics appears to be slowed down; (iii) by performing a mode analysis in terms of end-fixed Rouse chains, the slower dynamics is tracked to topological confinement within the cone spanned by the adjacent grafts; (iv) by adding 50% matrix chains, the topological confinement sensed by the grafted chain is lifted partially and the apparent chain motion is accelerated. We observe a crossover from pure Rouse motion at short times to topological confined motion beyond the time when the segmental mean squared displacement has reached the distance to the next graft.
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Affiliation(s)
- C Mark
- Jülich Centre for Neutron Science (JCNS) and Institute for Complex Systems (ICS), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - O Holderer
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenberstraße 1, 85747 Garching, Germany
| | - J Allgaier
- Jülich Centre for Neutron Science (JCNS) and Institute for Complex Systems (ICS), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - E Hübner
- Jülich Centre for Neutron Science (JCNS) and Institute for Complex Systems (ICS), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - W Pyckhout-Hintzen
- Jülich Centre for Neutron Science (JCNS) and Institute for Complex Systems (ICS), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - M Zamponi
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenberstraße 1, 85747 Garching, Germany
| | - A Radulescu
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenberstraße 1, 85747 Garching, Germany
| | - A Feoktystov
- Forschungszentrum Jülich GmbH, JCNS at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenberstraße 1, 85747 Garching, Germany
| | - M Monkenbusch
- Jülich Centre for Neutron Science (JCNS) and Institute for Complex Systems (ICS), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - N Jalarvo
- Forschungszentrum Jülich GmbH, JCNS at SNS-Oak Ridge National Laboratory (ORNL), 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA
| | - D Richter
- Jülich Centre for Neutron Science (JCNS) and Institute for Complex Systems (ICS), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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33
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Rok M, Szklarz P, Moskwa M, Kijewska M, Baran J, Bator G, Medycki W, Zamponi M. Structures and phase transitions in neat 4,4′-di-tert-butyl-2,2′-bipyridyl and in its molecular complexes with either bromanilic or iodanilic acid. CrystEngComm 2017. [DOI: 10.1039/c7ce01481c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using the DSC method, structural phase transitions (PTs) have been found at 165 and 219 K for 4,4′-di-tert-butyl-2,2′-bipyridyl (dtBBP), whereas for its complex with iodanilic acid (dtBBP·IA) PT is found at 331 K.
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Affiliation(s)
- M. Rok
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | - P. Szklarz
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | - M. Moskwa
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | - M. Kijewska
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | - J. Baran
- Institute of Low Temperature and Structure Research
- Polish Academy of Science
- 50-950 Wroclaw
- Poland
| | - G. Bator
- Faculty of Chemistry
- University of Wroclaw
- 50-383 Wroclaw
- Poland
| | - W. Medycki
- Institute of Molecular Physics
- Polish Academy of Sciences
- 60-179 Poznań
- Poland
| | - M. Zamponi
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ)
- Forschungszentrum Jülich GmbH
- 85748 Garching
- Germany
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34
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Stadler AM, Knieps-Grünhagen E, Bocola M, Lohstroh W, Zamponi M, Krauss U. Photoactivation Reduces Side-Chain Dynamics of a LOV Photoreceptor. Biophys J 2016; 110:1064-74. [PMID: 26958884 DOI: 10.1016/j.bpj.2016.01.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/08/2016] [Accepted: 01/20/2016] [Indexed: 11/17/2022] Open
Abstract
We used neutron-scattering experiments to probe the conformational dynamics of the light, oxygen, voltage (LOV) photoreceptor PpSB1-LOV from Pseudomonas putida in both the dark and light states. Global protein diffusion and internal macromolecular dynamics were measured using incoherent neutron time-of-flight and backscattering spectroscopy on the picosecond to nanosecond timescales. Global protein diffusion of PpSB1-LOV is not influenced by photoactivation. Observation-time-dependent global diffusion coefficients were found, which converge on the nanosecond timescale toward diffusion coefficients determined by dynamic light scattering. Mean-square displacements of localized internal motions and effective force constants, <k'>, describing the resilience of the proteins were determined on the respective timescales. Photoactivation significantly modifies the flexibility and the resilience of PpSB1-LOV. On the fast, picosecond timescale, small changes in the mean-square displacement and <k'> are observed, which are enhanced on the slower, nanosecond timescale. Photoactivation results in a slightly larger resilience of the photoreceptor on the fast, picosecond timescale, whereas in the nanosecond range, a significantly less resilient structure of the light-state protein is observed. For a residue-resolved interpretation of the experimental neutron-scattering data, we analyzed molecular dynamics simulations of the PpSB1-LOV X-ray structure. Based on these data, it is tempting to speculate that light-induced changes in the protein result in altered side-chain mobility mostly for residues on the protruding Jα helix and on the LOV-LOV dimer interface. Our results provide strong experimental evidence that side-chain dynamics play a crucial role in photoactivation and signaling of PpSB1-LOV via modulation of conformational entropy.
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Affiliation(s)
- Andreas M Stadler
- Jülich Centre for Neutron Science (JCNS) and Institute for Complex Systems (ICS), Forschungszentrum Jülich, Jülich, Germany.
| | - Esther Knieps-Grünhagen
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Marco Bocola
- Chair of Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Wiebke Lohstroh
- Heinz Maier-Leibnitz Zentrum, Technische Universität München, Garching, Germany
| | - Michaela Zamponi
- Jülich Centre for Neutron Science (JCNS), Outstation at MLZ, Forschungszentrum Jülich, Garching, Germany
| | - Ulrich Krauss
- Institute of Molecular Enzyme Technology, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
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35
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Grimaldo M, Roosen-Runge F, Hennig M, Zanini F, Zhang F, Jalarvo N, Zamponi M, Schreiber F, Seydel T. Hierarchical molecular dynamics of bovine serum albumin in concentrated aqueous solution below and above thermal denaturation. Phys Chem Chem Phys 2016; 17:4645-55. [PMID: 25587698 DOI: 10.1039/c4cp04944f] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dynamics of proteins in solution is a complex and hierarchical process, affected by the aqueous environment as well as temperature. We present a comprehensive study on nanosecond time and nanometer length scales below, at, and above the denaturation temperature Td. Our experimental data evidence dynamical processes in protein solutions on three distinct time scales. We suggest a consistent physical picture of hierarchical protein dynamics: (i) self-diffusion of the entire protein molecule is confirmed to agree with colloid theory for all temperatures where the protein is in its native conformational state. At higher temperatures T > Td, the self-diffusion is strongly obstructed by cross-linking or entanglement. (ii) The amplitude of backbone fluctuations grows with increasing T, and a transition in its dynamics is observed above Td. (iii) The number of mobile side-chains increases sharply at Td while their average dynamics exhibits only little variations. The combination of quasi-elastic neutron scattering and the presented analytical framework provides a detailed microscopic picture of the protein molecular dynamics in solution, thereby reflecting the changes of macroscopic properties such as cluster formation and gelation.
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Affiliation(s)
- Marco Grimaldo
- Institut Max von Laue - Paul Langevin (ILL), CS 20156, F-38042 Grenoble, France.
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36
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Unidad HJ, Goad MA, Bras AR, Zamponi M, Faust R, Allgaier J, Pyckhout-Hintzen W, Wischnewski A, Richter D, Fetters LJ. Consequences of Increasing Packing Length on the Dynamics of Polymer Melts. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b00341] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Herwin Jerome Unidad
- Jülich
Centre for Neutron Science, Outstation at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstraße 1, 85747 Garching, Germany
| | - Mahmoud Abdel Goad
- Jülich
Centre for Neutron Science-1 and Institute of Complex Systems-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Ana Rita Bras
- Jülich
Centre for Neutron Science-1 and Institute of Complex Systems-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Michaela Zamponi
- Jülich
Centre for Neutron Science, Outstation at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstraße 1, 85747 Garching, Germany
| | - Rudolf Faust
- Chemistry
Department, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
| | - Jürgen Allgaier
- Jülich
Centre for Neutron Science-1 and Institute of Complex Systems-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Wim Pyckhout-Hintzen
- Jülich
Centre for Neutron Science-1 and Institute of Complex Systems-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Andreas Wischnewski
- Jülich
Centre for Neutron Science-1 and Institute of Complex Systems-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Dieter Richter
- Jülich
Centre for Neutron Science-1 and Institute of Complex Systems-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Lewis J. Fetters
- Department
of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14850, United States
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37
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Hong L, Sharp MA, Poblete S, Biehl R, Zamponi M, Szekely N, Appavou MS, Winkler RG, Nauss RE, Johs A, Parks JM, Yi Z, Cheng X, Liang L, Ohl M, Miller SM, Richter D, Gompper G, Smith JC. Structure and dynamics of a compact state of a multidomain protein, the mercuric ion reductase. Biophys J 2015; 107:393-400. [PMID: 25028881 DOI: 10.1016/j.bpj.2014.06.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 05/30/2014] [Accepted: 06/10/2014] [Indexed: 12/11/2022] Open
Abstract
The functional efficacy of colocalized, linked protein domains is dependent on linker flexibility and system compaction. However, the detailed characterization of these properties in aqueous solution presents an enduring challenge. Here, we employ a novel, to our knowledge, combination of complementary techniques, including small-angle neutron scattering, neutron spin-echo spectroscopy, and all-atom molecular dynamics and coarse-grained simulation, to identify and characterize in detail the structure and dynamics of a compact form of mercuric ion reductase (MerA), an enzyme central to bacterial mercury resistance. MerA possesses metallochaperone-like N-terminal domains (NmerA) tethered to its catalytic core domain by linkers. The NmerA domains are found to interact principally through electrostatic interactions with the core, leashed by the linkers so as to subdiffuse on the surface over an area close to the core C-terminal Hg(II)-binding cysteines. How this compact, dynamical arrangement may facilitate delivery of Hg(II) from NmerA to the core domain is discussed.
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Affiliation(s)
- Liang Hong
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Tennessee; Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee; Department of Physics and Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai, China
| | - Melissa A Sharp
- European Spallation Source ESS AB, Lund, Sweden; Jülich Center of Neutron Science, Outstation at the Spallation Neutron Source (SNS), Oak Ridge, Tennessee
| | - Simón Poblete
- Institute of Complex Systems & Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich, Germany
| | - Ralf Biehl
- Jülich Center of Neutron Science & Institute of Complex Systems, Forschungszentrum Jülich, Jülich, Germany
| | - Michaela Zamponi
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH Outstation at MLZ, Garching, Germany
| | - Noemi Szekely
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH Outstation at MLZ, Garching, Germany
| | - Marie-Sousai Appavou
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH Outstation at MLZ, Garching, Germany
| | - Roland G Winkler
- Institute of Complex Systems & Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich, Germany
| | - Rachel E Nauss
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California
| | - Alexander Johs
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Jerry M Parks
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Tennessee
| | - Zheng Yi
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Tennessee; Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Xiaolin Cheng
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Tennessee
| | - Liyuan Liang
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Michael Ohl
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH Outstation at MLZ, Garching, Germany.
| | - Susan M Miller
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California.
| | - Dieter Richter
- Jülich Center of Neutron Science & Institute of Complex Systems, Forschungszentrum Jülich, Jülich, Germany.
| | - Gerhard Gompper
- Institute of Complex Systems & Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich, Germany.
| | - Jeremy C Smith
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Tennessee; Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee.
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38
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Monkenbusch M, Stadler A, Biehl R, Ollivier J, Zamponi M, Richter D. Fast internal dynamics in alcohol dehydrogenase. J Chem Phys 2015; 143:075101. [DOI: 10.1063/1.4928512] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Grimaldo M, Roosen-Runge F, Hennig M, Zanini F, Zhang F, Zamponi M, Jalarvo N, Schreiber F, Seydel T. Salt-Induced Universal Slowing Down of the Short-Time Self-Diffusion of a Globular Protein in Aqueous Solution. J Phys Chem Lett 2015; 6:2577-2582. [PMID: 26266736 DOI: 10.1021/acs.jpclett.5b01073] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The short-time self-diffusion D of the globular model protein bovine serum albumin in aqueous (D2O) solutions has been measured comprehensively as a function of the protein and trivalent salt (YCl3) concentration, noted cp and cs, respectively. We observe that D follows a universal master curve D(cs,cp) = D(cs = 0,cp) g(cs/cp), where D(cs = 0,cp) is the diffusion coefficient in the absence of salt and g(cs/cp) is a scalar function solely depending on the ratio of the salt and protein concentration. This observation is consistent with a universal scaling of the bonding probability in a picture of cluster formation of patchy particles. The finding corroborates the predictive power of the description of proteins as colloids with distinct attractive ion-activated surface patches.
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Affiliation(s)
- Marco Grimaldo
- †Institut Max von Laue - Paul Langevin (ILL), CS 20156, 71 avenue des Martyrs, F-38042 Grenoble, France
- ‡Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany
| | - Felix Roosen-Runge
- †Institut Max von Laue - Paul Langevin (ILL), CS 20156, 71 avenue des Martyrs, F-38042 Grenoble, France
| | - Marcus Hennig
- †Institut Max von Laue - Paul Langevin (ILL), CS 20156, 71 avenue des Martyrs, F-38042 Grenoble, France
- ‡Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany
| | - Fabio Zanini
- ‡Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany
| | - Fajun Zhang
- ‡Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany
| | - Michaela Zamponi
- §Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
- ∥JCNS Outstation at the MLZ, Lichtenbergstraße 1, D-85747 Garching, Germany
| | - Niina Jalarvo
- §Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
- ⊥Chemical and Engineering Materials Division, Neutron Sciences Directorate, and JCNS Outstation at the Spallation Neutron Source (SNS), Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States
| | - Frank Schreiber
- ‡Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany
| | - Tilo Seydel
- †Institut Max von Laue - Paul Langevin (ILL), CS 20156, 71 avenue des Martyrs, F-38042 Grenoble, France
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40
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Grimaldo M, Roosen-Runge F, Jalarvo N, Zamponi M, Zanini F, Hennig M, Zhang F, Schreiber F, Seydel T. High-resolution neutron spectroscopy on protein solution samples. EPJ Web of Conferences 2015. [DOI: 10.1051/epjconf/20158302005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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41
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Bhowmik D, Pomposo JA, Juranyi F, García Sakai V, Zamponi M, Arbe A, Colmenero J. Investigation of a Nanocomposite of 75 wt % Poly(methyl methacrylate) Nanoparticles with 25 wt % Poly(ethylene oxide) Linear Chains: A Quasielatic Neutron Scattering, Calorimetric, and WAXS Study. Macromolecules 2014. [DOI: 10.1021/ma500215f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- D. Bhowmik
- Donostia International Physics
Center, Paseo Manuel de Lardizabal
4, 20018 San Sebastián, Spain
| | - J. A. Pomposo
- Centro de Física de Materiales (CSIC−UPV/EHU)
− Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Departamento
de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain
- IKERBASQUE
- Basque Foundation for Science, Alameda
Urquijo 36, 48011 Bilbao, Spain
| | - F. Juranyi
- Laboratory for Neutron
Scattering, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - V. García Sakai
- ISIS Facility, Rutherford Appleton Laboratory, Harwell Science & Innovation Campus, Chilton, Didcot OX11 0QX, United Kingdom
| | - M. Zamponi
- Jülich
Centre for Neutron Science, Forschungszentrum Jülich GmbH, outstation at Heinz
Maier-Leibnitz Zentrum, Lichtenbergstr. 1, 85747 Garching, Germany
| | - A. Arbe
- Centro de Física de Materiales (CSIC−UPV/EHU)
− Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - J. Colmenero
- Donostia International Physics
Center, Paseo Manuel de Lardizabal
4, 20018 San Sebastián, Spain
- Centro de Física de Materiales (CSIC−UPV/EHU)
− Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Departamento
de Física de Materiales, UPV/EHU, Apartado 1072, 20080 San Sebastián, Spain
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Bhowmik D, Pomposo JA, Juranyi F, García-Sakai V, Zamponi M, Su Y, Arbe A, Colmenero J. Microscopic Dynamics in Nanocomposites of Poly(ethylene oxide) and Poly(methyl methacrylate) Soft Nanoparticles: A Quasi-Elastic Neutron Scattering Study. Macromolecules 2013. [DOI: 10.1021/ma402023n] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- D. Bhowmik
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
| | - J. A. Pomposo
- Centro de Física de Materiales (CSIC−UPV/EHU)—Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
- Departamento de Física de Materiales (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain
- IKERBASQUE—Basque Foundation for Science, Alameda Urquijo 36, 48011 Bilbao, Spain
| | - F. Juranyi
- Laboratory
for Neutron Scattering, Paul Scherrer Institut CH-5232 Villigen, Switzerland
| | - V. García-Sakai
- ISIS Facility, Rutherford Appleton Laboratory, Harwell Science & Innovation Campus, Chilton, Didcot, OX11 0QX, U.K
| | - M. Zamponi
- Jülich
Centre for Neutron Science, Forschungszentrum Jülich GmbH, outstation at Heinz
Maier-Leibnitz Zentrum, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Y. Su
- Jülich
Centre for Neutron Science, Forschungszentrum Jülich GmbH, outstation at Heinz
Maier-Leibnitz Zentrum, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - A. Arbe
- Centro de Física de Materiales (CSIC−UPV/EHU)—Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
| | - J. Colmenero
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
- Centro de Física de Materiales (CSIC−UPV/EHU)—Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain
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Wuttke J, Zamponi M. Simulation-guided optimization of small-angle analyzer geometry in the neutron backscattering spectrometer SPHERES. Rev Sci Instrum 2013; 84:115108. [PMID: 24289438 DOI: 10.1063/1.4831815] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The resolution of neutron backscattering spectrometers deteriorates at small scattering angles where analyzers deviate from exact backscattering. By reducing the azimuth angle range of the analyzers, the resolution can be improved with little loss of peak intensity. Measurements at the spectrometer SPHERES are in excellent agreement with simulations, which proves the dominance of geometric effects.
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Affiliation(s)
- Joachim Wuttke
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstraße 1, 85747 Garching, Germany
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Gerstl C, Schneider GJ, Fuxman A, Zamponi M, Frick B, Seydel T, Koza M, Genix AC, Allgaier J, Richter D, Colmenero J, Arbe A. Quasielastic Neutron Scattering Study on the Dynamics of Poly(alkylene oxide)s. Macromolecules 2012. [DOI: 10.1021/ma3003399] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- C. Gerstl
- Jülich Centre
for Neutron Science (JCNS 1) and Institut for Complex Systems (ICS
1), Forschungszentrum Jülich GmbH, D−52425 Jülich, Germany
- Jülich Centre for Neutron Science (JCNS 1), Outstation at FRM II, 85747 Garching, Germany
| | - G. J. Schneider
- Jülich Centre for Neutron Science (JCNS 1), Outstation at FRM II, 85747 Garching, Germany
| | - A. Fuxman
- Jülich Centre for Neutron Science (JCNS 1), Outstation at FRM II, 85747 Garching, Germany
| | - M. Zamponi
- Jülich Centre for Neutron Science (JCNS 1), Outstation at FRM II, 85747 Garching, Germany
| | - B. Frick
- Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - T. Seydel
- Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - M. Koza
- Institut Laue−Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - A.-C. Genix
- Laboratoire Charles Coulomb, UMR 5221, CNRS and Université Montpellier 2, 34095 Montpellier,
France
| | - J. Allgaier
- Jülich Centre
for Neutron Science (JCNS 1) and Institut for Complex Systems (ICS
1), Forschungszentrum Jülich GmbH, D−52425 Jülich, Germany
| | - D. Richter
- Jülich Centre
for Neutron Science (JCNS 1) and Institut for Complex Systems (ICS
1), Forschungszentrum Jülich GmbH, D−52425 Jülich, Germany
- Jülich Centre for Neutron Science (JCNS 1), Outstation at FRM II, 85747 Garching, Germany
| | - J. Colmenero
- Centro de Física de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, E-20018 San
Sebastián, Spain
- Departamento de Física de Materiales (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián,
Spain
| | - A. Arbe
- Centro de Física de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, E-20018 San
Sebastián, Spain
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Abstract
Transitions within the tunneling multiplet of CH(4) in phase II have been measured in an experiment at the backscattering instrument BASIS of the Neutron Source SNS. They all involve transitions from or to T-states. A statistical model is put forward which accounts for local departures from tetrahedral symmetry at the sites of ordered molecules. Different from previous work, in which discrete sets of overlap matrix elements have been studied, now large numbers of elements as well as the ensemble of T-states are considered. The observed neutron spectra can be explained rather well, all based on the pocket state formalism of A. Hüller [Phys. Rev. B 16, 1844 (1977)]. A completely new result is the observation and simulation of transitions between T-states, which give rise to a double peaked feature close to the elastic position and which reflect the disorder in the system. CH(2)D(2) molecules in the CH(4) matrix are largely responsible for the disorder and an interesting topic for their own sake. The simple model presented may lend itself to a broader application.
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Affiliation(s)
- Werner Press
- Institut für Experimentelle und Angewandte Physik der Christian-Albrechts-Universität Kiel, Olshausenstr. 40, D-24098 Kiel, Germany.
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Zamponi M, Pyckhout-Hintzen W, Wischnewski A, Monkenbusch M, Willner L, Kali G, Richter D. Molecular Observation of Branch Point Motion in Star Polymer Melts. Macromolecules 2009. [DOI: 10.1021/ma9017185] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | | | | | - György Kali
- Institut Laue-Langevin, 6 rue Jules Horowitz, 38000 Grenoble, France
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Zamponi M, Wischnewski A, Monkenbusch M, Willner L, Richter D, Falus P, Farago B, Guenza MG. Cooperative dynamics in homopolymer melts: a comparison of theoretical predictions with neutron spin echo experiments. J Phys Chem B 2009; 112:16220-9. [PMID: 19072142 DOI: 10.1021/jp807035z] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a comparison between theoretical predictions of the generalized Langevin equation for cooperative dynamics (CDGLE) and neutron spin echo data of dynamic structure factors for polyethylene melts. Experiments cover an extended range of length and time scales, providing a compelling test for the theoretical approach. Samples investigated include chains with increasing molecular weights undergoing dynamics across the unentangled to entangled transition. Measured center-of-mass (com) mean-square displacements display a crossover from subdiffusive to diffusive dynamics. The generalized Langevin equation for cooperative dynamics relates this anomalous diffusion to the presence of the interpolymer potential, which correlates the dynamics of a group of slowly diffusing molecules in a dynamically heterogeneous liquid. Theoretical predictions of the subdiffusive behavior, of its crossover to free diffusion, and of the number of macromolecules undergoing cooperative motion are in quantitative agreement with experiments.
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Affiliation(s)
- M Zamponi
- Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich, Germany
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Ehlers G, Mamontov E, Zamponi M, Kam KC, Gardner JS. Direct observation of a nuclear spin excitation in Ho2Ti2O7. Phys Rev Lett 2009; 102:016405. [PMID: 19257221 DOI: 10.1103/physrevlett.102.016405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Indexed: 05/27/2023]
Abstract
A single nondispersive excitation is observed by means of neutron backscattering, at E_{0}=26.3 microeV in the spin ice Ho2Ti2O7 but not in the isotopically enriched 162Dy2Ti2O7 analogue. The intensity of this excitation is rather small, less, similar0.2% of the elastic intensity. It is clearly observed below 80 K but resolution limited only below approximately 65 K. The application of a magnetic field up to micro_{0}H=4.5 T, at 1.6 K, has no measurable effect on the energy or intensity. This nuclear excitation is believed to perturb the electronic, Ising spin system resulting in the persistent spin dynamics observed in spin ice compounds.
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Affiliation(s)
- G Ehlers
- Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6475, USA
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Ehlers G, Mamontov E, Zamponi M, Faraone A, Qiu Y, Cornelius AL, Booth CH, Kam KC, Toquin RL, Cheetham AK, Gardner JS. Frustrated spin correlations in diluted spin ice Ho(2-x)La(x)Ti(2)O(7). J Phys Condens Matter 2008; 20:235206. [PMID: 21694297 DOI: 10.1088/0953-8984/20/23/235206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have studied the evolution of the structural properties as well as the static and dynamic spin correlations of spin ice Ho(2)Ti(2)O(7), where Ho was partially replaced by non-magnetic La. The crystal structure of diluted samples Ho(2-x)La(x)Ti(2)O(7) was characterized by x-ray and neutron diffraction and by Ho L(III)-edge and Ti K-edge extended x-ray absorption fine structure (EXAFS) measurements. It is found that the pyrochlore structure remains intact until about x = 0.3, but a systematic increase in local disorder with increasing La concentration is observed in the EXAFS data, especially from the Ti K edge. Quasi-elastic neutron scattering and ac susceptibility measurements show that, in x≤0.4 samples at temperatures above macroscopic freezing, the spin-spin correlations are short ranged and dynamic in nature. The main difference with pure spin ice in the dynamics is the appearance of a second, faster, relaxation process.
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Affiliation(s)
- G Ehlers
- Spallation Neutron Source, Oak Ridge National Laboratory, Building 8600, Oak Ridge, TN 37831-6475, USA
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