1
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Bange L, Mukhina T, Fragneto G, Rondelli V, Schneck E. Influence of adhesion-promoting glycolipids on the structure and stability of solid-supported lipid double-bilayers. SOFT MATTER 2024; 20:2113-2125. [PMID: 38349522 DOI: 10.1039/d3sm01615c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Glycolipids have a considerable influence on the interaction between adjacent biomembranes and can promote membrane adhesion trough favorable sugar-sugar "bonds" even at low glycolipid fractions. Here, in order to obtain structural insights into this phenomenon, we utilize neutron reflectometry in combination with a floating lipid bilayer architecture that brings two glycolipid-loaded lipid bilayers to close proximity. We find that selected glycolipids with di-, or oligosaccharide headgroups affect the inter-bilayer water layer thickness and appear to contribute to the stability of the double-bilayer architecture by promoting adhesion of adjacent bilayers even against induced electrostatic repulsion. However, we do not observe any redistribution of glycolipids that would maximize the density of sugar-sugar contacts. Our results point towards possible strategies for the investigation of interactions between cell surfaces involving specific protein-protein, lipid-lipid, or protein-lipid binding.
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Affiliation(s)
- Lukas Bange
- Institute for Condensed Matter Physics, TU Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany.
| | - Tetiana Mukhina
- Institute for Condensed Matter Physics, TU Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany.
| | - Giovanna Fragneto
- Institut Laue-Langevin, Grenoble, France
- The European Spallation Source, ERIC, Lund, Sweden
| | - Valeria Rondelli
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Italy.
| | - Emanuel Schneck
- Institute for Condensed Matter Physics, TU Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany.
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2
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Cezar HM, Cascella M. SANS Spectra with PLUMED: Implementation and Application to Metainference. J Chem Inf Model 2023; 63:4979-4985. [PMID: 37552250 PMCID: PMC10466380 DOI: 10.1021/acs.jcim.3c00724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Indexed: 08/09/2023]
Abstract
Using small-angle scattering with either X-ray or neutron sources has become common in the investigation of soft-matter systems. These experiments provide information about the coarse shape of the scattered objects, but obtaining more-detailed information can usually only be achieved with the aid of molecular simulations. In this Application Note, we report the implementation of an extension in PLUMED to compute the small-angle neutron scattering (SANS), which can be used for data processing as well for enhanced sampling, in particular with the metainference method to bias simulations and sample structures with a resulting spectrum in agreement with an experimental reference. Our implementation includes a resolution function that can be used to smear the SANS intensities according to beamline error sources and is compatible with both all-atom and coarse-grained simulations. Scripts to aid in the calculation of the scattering lengths when the system is coarse-grained and to aid in preparing the inputs are provided. We illustrate the use of the implementation with metainference by performing coarse-grained simulations of beta-octylglucoside and dodecylphosphocholine micelles in water. With different software and different Hamiltonians, we show that the metainference SANS bias can drive micelles to be split and to change shapes to achieve a better agreement with the experimental reference.
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Affiliation(s)
- Henrique M. Cezar
- Hylleraas Centre for Quantum Molecular
Sciences and Department of Chemistry, University
of Oslo, PO Box 1033
Blindern, 0315 Oslo, Norway
| | - Michele Cascella
- Hylleraas Centre for Quantum Molecular
Sciences and Department of Chemistry, University
of Oslo, PO Box 1033
Blindern, 0315 Oslo, Norway
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3
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Ibrahim M, Gilbert J, Heinz M, Nylander T, Schwierz N. Structural insights on ionizable Dlin-MC3-DMA lipids in DOPC layers by combining accurate atomistic force fields, molecular dynamics simulations and neutron reflectivity. NANOSCALE 2023. [PMID: 37377412 DOI: 10.1039/d3nr00987d] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Ionizable lipids such as the promising Dlin-MC3-DMA (MC3) are essential for the successful design of lipid nanoparticles (LNPs) as drug delivery agents. Combining molecular dynamics simulations with experimental data, such as neutron reflectivity experiments and other scattering techniques, is essential to provide insights into the internal structure of LNPs, which is not fully understood to date. However, the accuracy of the simulations relies on the choice of force field parameters and high-quality experimental data is indispensable to verify the parametrization. For MC3, different parameterizations in combination with the CHARMM and the Slipids force fields have recently emerged. Here, we complement the existing efforts by providing parameters for cationic and neutral MC3 compatible with the AMBER Lipid17 force field. Subsequently, we carefully assess the accuracy of the different force fields by providing a direct comparison to neutron reflectivity experiments of mixed lipid bilayers consisting of MC3 and DOPC at different pHs. At low pH (cationic MC3) and at high pH (neutral MC3) the newly developed MC3 parameters in combination with AMBER Lipid17 for DOPC give good agreement with the experiments. Overall, the agreement is similar compared to the Park-Im parameters for MC3 in combination with the CHARMM36 force field for DOPC. The Ermilova-Swenson MC3 parameters in combination with the Slipids force field underestimate the bilayer thickness. While the distribution of cationic MC3 is very similar, the different force fields for neutral MC3 reveal distinct differences ranging from strong accumulation in the membrane center (current MC3/AMBER Lipid17 DOPC), over mild accumulation (Park-Im MC3/CHARMM36 DOPC) to surface accumulation (Ermilova-Swenson MC3/Slipids DOPC). These pronounced differences highlight the importance of accurate force field parameters and their experimental validation.
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Affiliation(s)
- Mohd Ibrahim
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
| | - Jennifer Gilbert
- Physical Chemistry, Department of Chemistry Lund University, P.O Box 124, SE-22100 Lund, Sweden.
- NanoLund, Lund University, Professorsgatan 1, 223 63 Lund, Sweden
| | - Marcel Heinz
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
| | - Tommy Nylander
- Physical Chemistry, Department of Chemistry Lund University, P.O Box 124, SE-22100 Lund, Sweden.
- NanoLund, Lund University, Professorsgatan 1, 223 63 Lund, Sweden
- LINXS Institute of Advanced Neutron and X-Ray Science, Scheelevägen 19, 223 70, Lund, Sweden
- School of Chemical Engineering and Translational Nanobioscience Research Center, Sungkyunkwan University, Suwon, Republic of Korea
| | - Nadine Schwierz
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany
- Institute of Physics, University of Augsburg, 86159 Augsburg, Germany.
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4
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Gavutis M, Schulze-Niemand E, Lee HH, Liedberg B, Stein M, Valiokas R. Bilayer lipid membrane formation on surface assemblies with sparsely distributed tethers. NANOSCALE 2023. [PMID: 37128711 DOI: 10.1039/d2nr07069c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A combined computational and experimental study of small unilamellar vesicle (SUV) fusion on mixed self-assembled monolayers (SAMs) terminated with different deuterated tether moieties (-(CD2)7CD3 or -(CD2)15CD3) is reported. Tethered bilayer lipid membrane (tBLM) formation of synthetic 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine was initially probed on SAMs with controlled tether (d-alkyl tail) surface densities and lateral molecular packing using quartz crystal microbalance with dissipation monitoring (QCM-D). Long time-scale coarse-grained molecular dynamics (MD) simulations were then employed to elucidate the mechanisms behind the interaction between the SUVs and the different phases formed by the -(CD2)7CD3 and -(CD2)15CD3 tethers. Furthermore, a series of real time kinetics was recorded under different osmotic conditions using QCM-D to determine the accumulated lipid mass and for probing the fusion process. It is shown that the key factors driving the SUV fusion and tBLM formation on this type of surfaces involve tether insertion into the SUVs along with vesicle deformation. It is also evident that surface densities of the tethers as small as a few mol% are sufficient to obtain stable tBLMs with a high reproducibility. The described "sparsely tethered" tBLM system can be advantageous in studying different biophysical phenomena, such as membrane protein insertion, effects of receptor clustering, and raft formation.
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Affiliation(s)
- Martynas Gavutis
- Department of Nanoengineering, Center for Physical Sciences and Technology, Savanorių 231, 02300 Vilnius, Lithuania.
| | - Eric Schulze-Niemand
- Molecular Simulations and Design Group, Max Planck Institute for Dynamics of Complex Technical System, Magdeburg, Germany
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, 39120 Magdeburg, Germany
| | - Hung-Hsun Lee
- Division of Molecular Physics, Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
| | - Bo Liedberg
- Division of Molecular Physics, Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
| | - Matthias Stein
- Molecular Simulations and Design Group, Max Planck Institute for Dynamics of Complex Technical System, Magdeburg, Germany
| | - Ramūnas Valiokas
- Department of Nanoengineering, Center for Physical Sciences and Technology, Savanorių 231, 02300 Vilnius, Lithuania.
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5
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Schaefer SL, Hummer G. Sublytic gasdermin-D pores captured in atomistic molecular simulations. eLife 2022; 11:e81432. [PMID: 36374182 PMCID: PMC9699695 DOI: 10.7554/elife.81432] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 11/11/2022] [Indexed: 11/16/2022] Open
Abstract
Gasdermin-D (GSDMD) is the ultimate effector of pyroptosis, a form of programmed cell death associated with pathogen invasion and inflammation. After proteolytic cleavage by caspases, the GSDMD N-terminal domain (GSDMDNT) assembles on the inner leaflet of the plasma membrane and induces the formation of membrane pores. We use atomistic molecular dynamics simulations to study GSDMDNT monomers, oligomers, and rings in an asymmetric plasma membrane mimetic. We identify distinct interaction motifs of GSDMDNT with phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) and phosphatidylserine (PS) headgroups and describe their conformational dependence. Oligomers are stabilized by shared lipid binding sites between neighboring monomers acting akin to double-sided tape. We show that already small GSDMDNT oligomers support stable, water-filled, and ion-conducting membrane pores bounded by curled beta-sheets. In large-scale simulations, we resolve the process of pore formation from GSDMDNT arcs and lipid efflux from partial rings. We find that high-order GSDMDNT oligomers can crack under the line tension of 86 pN created by an open membrane edge to form the slit pores or closed GSDMDNT rings seen in atomic force microscopy experiments. Our simulations provide a detailed view of key steps in GSDMDNT-induced plasma membrane pore formation, including sublytic pores that explain nonselective ion flux during early pyroptosis.
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Affiliation(s)
- Stefan L Schaefer
- Department of Theoretical Biophysics, Max Planck Institute of BiophysicsFrankfurt am MainGermany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of BiophysicsFrankfurt am MainGermany
- Institute of Biophysics, Goethe University FrankfurtFrankfurt am MainGermany
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6
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Zhang Y, Liu D, Zhang Y, Guo Y, Li W, THALMANN F. Coarse-grained description of monounsaturated peroxidized phospholipidbilayers. J Chem Phys 2022; 157:085103. [DOI: 10.1063/5.0096658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Lipid peroxides result from a reaction between cis-unsaturated lipid chains and singlet oxygen molecules leading to the addition of a peroxide OOH side group next to the acyl-chain double bond. It is now established that HP-POPC (hydroperoxidized POPC) molecules form stable, thin and laterally expanded bilayers. The difference in structural organisation arises from the hydrophilic character of the OOH side group that has strong affinity with the water interface region, leading to significant reorganisation of the bilayer. In this Article we describe a coarse-grained (CG) model of POPC and DOPC lipid peroxides within the framework of the Martini CG force-field (v2.2), derived from experimental data. We then discuss extensively the predicted structure and the influence of hydration and show how shifting the position of the unsaturated bonds along the chain changes the structure. Finally, we provide electron and neutron scattering length density profiles of the simulated bilayers.
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Affiliation(s)
| | - DongHui Liu
- Nanjing University Department of Physics, China
| | | | - Yachong Guo
- Nanjing University Kuang Yaming Honors School, China
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7
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Deboever E, Van Aubel G, Rondelli V, Koutsioubas A, Mathelie-Guinlet M, Dufrene YF, Ongena M, Lins L, Van Cutsem P, Fauconnier ML, Deleu M. Modulation of plant plasma membrane structure by exogenous fatty acid hydroperoxide is a potential perception mechanism for their eliciting activity. PLANT, CELL & ENVIRONMENT 2022; 45:1082-1095. [PMID: 34859447 DOI: 10.1111/pce.14239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 11/10/2021] [Accepted: 11/16/2021] [Indexed: 06/13/2023]
Abstract
Oxylipins are lipid-derived molecules that are ubiquitous in eukaryotes and whose functions in plant physiology have been widely reported. They appear to play a major role in plant immunity by orchestrating reactive oxygen species (ROS) and hormone-dependent signalling pathways. The present work focuses on the specific case of fatty acid hydroperoxides (HPOs). Although some studies report their potential use as exogenous biocontrol agents for plant protection, evaluation of their efficiency in planta is lacking and no information is available about their mechanism of action. In this study, the potential of 13(S)-hydroperoxy-(9Z, 11E)-octadecadienoic acid (13-HPOD) and 13(S)-hydroperoxy-(9Z, 11E, 15Z)-octadecatrienoic acid (13-HPOT), as plant defence elicitors and the underlying mechanism of action is investigated. Arabidopsis thaliana leaf resistance to Botrytis cinerea was observed after root application with HPOs. They also activate early immunity-related defence responses, like ROS. As previous studies have demonstrated their ability to interact with plant plasma membranes (PPM), we have further investigated the effects of HPOs on biomimetic PPM structure using complementary biophysics tools. Results show that HPO insertion into PPM impacts its global structure without solubilizing it. The relationship between biological assays and biophysical analysis suggests that lipid amphiphilic elicitors that directly act on membrane lipids might trigger early plant defence events.
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Affiliation(s)
- Estelle Deboever
- Laboratory of Molecular Biophysics at Interfaces, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
- Laboratory of Natural Molecules Chemistry, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
- FytoFend S.A., Isnes, Belgium
| | - Géraldine Van Aubel
- FytoFend S.A., Isnes, Belgium
- Research Unit in Plant Cellular and Molecular Biology, University of Namur, Namur, Belgium
| | - Valeria Rondelli
- Department of Medical Biotechnologies and Translational Medicine, Università degli Studi di Milano, Segrate, Italy
| | - Alexandros Koutsioubas
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Garching, Germany
| | | | - Yves F Dufrene
- Institute of Biomolecular Science and Technology (IBST), Louvain-la-Neuve, Belgium
| | - Marc Ongena
- Microbial Processes and Interactions (MiPI), Gembloux Agro-Bio Tech, Université de Liège, Gembloux, Belgium
| | - Laurence Lins
- Laboratory of Molecular Biophysics at Interfaces, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Pierre Van Cutsem
- FytoFend S.A., Isnes, Belgium
- Research Unit in Plant Cellular and Molecular Biology, University of Namur, Namur, Belgium
| | - Marie-Laure Fauconnier
- Laboratory of Natural Molecules Chemistry, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
| | - Magali Deleu
- Laboratory of Molecular Biophysics at Interfaces, Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
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8
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Carbohydrate-carbohydrate interaction drives the preferential insertion of dirhamnolipid into glycosphingolipid enriched membranes. J Colloid Interface Sci 2022; 616:739-748. [PMID: 35247812 DOI: 10.1016/j.jcis.2022.02.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/04/2022] [Accepted: 02/24/2022] [Indexed: 11/22/2022]
Abstract
Rhamnolipids (RLs) are among the most important biosurfactants produced by microorganisms, and have been widely investigated because of their multiple biological activities. Their action appears to depend on their structural interference with lipid membranes, therefore several studies have been performed to investigate this aspect. We studied by X-ray scattering, neutron reflectometry and molecular dynamic simulations the insertion of dirhamnolipid (diRL), the most abundant RL, in model cellular membranes made of phospholipids and glycosphingolipids. In our model systems the affinity of diRL to the membrane is highly promoted by the presence of the glycosphingolipids and molecular dynamics simulations unveil that this evidence is related to sugar-sugar attractive interactions at the membrane surface. Our results improve the understanding of the plethora of activities associated with RLs, also opening new perspectives in their selective use for pharmaceutical and cosmetics formulations. Additionally, they shed light on the still debated role of carbohydrate-carbohydrate interactions as driving force for molecular contacts at membrane surface.
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9
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Koutsioubas A. anaklasis: a compact software package for model-based analysis of specular neutron and X-ray reflectometry data sets. J Appl Crystallogr 2021; 54:1857-1866. [PMID: 34963772 PMCID: PMC8662969 DOI: 10.1107/s1600576721009262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 09/06/2021] [Indexed: 11/17/2022] Open
Abstract
A new software package (anaklasis) for model-based analysis of specular neutron and X-ray reflectivity is introduced. Key features include a user-friendly compact interfacial model definition scheme and a complete set of methods for co-refining data and estimating parameter uncertainty. anaklasis constitutes a set of open-source Python scripts that facilitate a range of specular neutron and X-ray reflectivity calculations, involving the generation of theoretical curves and the comparison/fitting of interfacial model reflectivity against experimental data sets. The primary focus of the software is twofold: on one hand to offer a more natural framework for model definition, requiring minimum coding literacy, and on the other hand to include advanced analysis methods that have been proposed in recent work. Particular attention is given to the ability to co-refine reflectivity data and to the estimation of model-parameter uncertainty and covariance using bootstrap analysis and Markov chain Monte Carlo sampling. The compactness and simplicity of model definition together with the streamlined analysis do not present a steep learning curve for the user, an aspect that may accelerate the generation of reproducible, easily readable and statistically accurate reports in future neutron and X-ray reflectivity related literature.
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Affiliation(s)
- Alexandros Koutsioubas
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstrasse 1, 85748 Garching, Germany
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10
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Rondelli V, Koutsioubas A, Pršić J, Deboever E, Crowet JM, Lins L, Deleu M. Sitosterol and glucosylceramide cooperative transversal and lateral uneven distribution in plant membranes. Sci Rep 2021; 11:21618. [PMID: 34732753 PMCID: PMC8566578 DOI: 10.1038/s41598-021-00696-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 10/05/2021] [Indexed: 11/13/2022] Open
Abstract
The properties of biomembranes depend on the presence, local structure and relative distribution assumed by the thousands of components it is made of. As for animal cells, plant membranes have been demonstrated to be organized in subdomains with different persistence lengths and times. In plant cells, sitosterol has been demonstrated to confer to phospholipid membranes a more ordered structure while among lipids, glycosphingolipids are claimed to form rafts where they tightly pack with sterols. Glucosylceramides are glycosphingolipids involved in plant signalling and are essential for viability of cells and whole plant. The glucosylceramide-sitosterol structural coupling within PLPC membranes is here investigated by Langmuir films, in silico simulations and neutron reflectometry, unveiling that a strong direct interaction between the two molecules exists and governs their lateral and transversal distribution within membrane leaflets. The understanding of the driving forces governing specific molecules clustering and segregation in subdomains, such as glucosylceramide and sitosterol, have an impact on the mechanical properties of biomembranes and could reflect in the other membrane molecules partitioning and activity.
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Affiliation(s)
- V Rondelli
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milano, Italy.
| | - A Koutsioubas
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Garching, Germany.
| | - J Pršić
- Microbial Processes and Interactions Laboratory (MiPI), TERRA Research Center, Gembloux Agro-Bio Tech, Université de Liège, Gembloux, Belgium
| | - E Deboever
- Laboratoire de Biophysique Moléculaire aux Interfaces, Structure Fédérative de Recherche Condorcet, TERRA Research Center, Gembloux Agro-Bio Tech, Université de Liège, Gembloux, Belgium.,Laboratory of Natural Molecules Chemistry, Gembloux Agro-Bio Tech, University of Liège, 2, Passage des Déportés, 5030, Gembloux, Belgium.,FytoFend S.A., rue Georges Legrand, 6, 5032, Isnes, Belgium
| | - J M Crowet
- Université de Reims Champagne-Ardenne, UFR Sciences Exactes et Naturelles, Reims, France
| | - L Lins
- Laboratoire de Biophysique Moléculaire aux Interfaces, Structure Fédérative de Recherche Condorcet, TERRA Research Center, Gembloux Agro-Bio Tech, Université de Liège, Gembloux, Belgium
| | - M Deleu
- Laboratoire de Biophysique Moléculaire aux Interfaces, Structure Fédérative de Recherche Condorcet, TERRA Research Center, Gembloux Agro-Bio Tech, Université de Liège, Gembloux, Belgium.
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11
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Savenko M, Rivel T, Yesylevskyy S, Ramseyer C. Influence of Substrate Hydrophilicity on Structural Properties of Supported Lipid Systems on Graphene, Graphene Oxides, and Silica. J Phys Chem B 2021; 125:8060-8074. [PMID: 34284579 DOI: 10.1021/acs.jpcb.1c04615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pristine graphene, a range of graphene oxides, and silica substrates were used to investigate the effect of surface hydrophilicity on supported lipid bilayers by means of all-atom molecular dynamics simulations. Supported 1,2-dioleoyl-sn-glycero-3-phosphocholine lipid bilayers were found in close-contact conformations with hydrophilic substrates with as low as 5% oxidation level, while self-assembled monolayers occur on pure hydrophobic graphene only. Lipids and water at the surface undergo large redistribution to maintain the stability of the supported bilayers. Deposition of bicelles on increasingly hydrophilic substrates shows the continuous process of reshaping of the supported system and makes intermediate stages between self-assembled monolayers and supported bilayers. The bilayer thickness changes with hydrophilicity in a complex manner, while the number of water molecules per lipid in the hydration layer increases together with hydrophilicity.
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Affiliation(s)
- Mariia Savenko
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France
| | - Timothée Rivel
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France.,CEITEC - Central European Institute of Technology, Masaryk University, Kamenice, CZ-62500 Brno, Czech Republic.,National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice, CZ-62500 Brno, Czech Republic
| | - Semen Yesylevskyy
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France.,Department of Physics of Biological Systems, Institute of Physics of the National Academy of Sciences of Ukraine, Prospect Nauky 46, 03028 Kyiv, Ukraine
| | - Christophe Ramseyer
- Laboratoire Chrono Environnement UMR CNRS 6249, Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France
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12
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Zec N, Mangiapia G, Hendry AC, Barker R, Koutsioubas A, Frielinghaus H, Campana M, Ortega-Roldan JL, Busch S, Moulin JF. Mutually Beneficial Combination of Molecular Dynamics Computer Simulations and Scattering Experiments. MEMBRANES 2021; 11:507. [PMID: 34357157 PMCID: PMC8304056 DOI: 10.3390/membranes11070507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 11/17/2022]
Abstract
We showcase the combination of experimental neutron scattering data and molecular dynamics (MD) simulations for exemplary phospholipid membrane systems. Neutron and X-ray reflectometry and small-angle scattering measurements are determined by the scattering length density profile in real space, but it is not usually possible to retrieve this profile unambiguously from the data alone. MD simulations predict these density profiles, but they require experimental control. Both issues can be addressed simultaneously by cross-validating scattering data and MD results. The strengths and weaknesses of each technique are discussed in detail with the aim of optimizing the opportunities provided by this combination.
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Affiliation(s)
- Nebojša Zec
- German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Hereon, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (N.Z.); (G.M.)
| | - Gaetano Mangiapia
- German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Hereon, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (N.Z.); (G.M.)
| | - Alex C. Hendry
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, UK; (A.C.H.); (J.L.O.-R.)
| | - Robert Barker
- School of Physical Sciences, University of Kent, Canterbury CT2 7NH, UK;
| | - Alexandros Koutsioubas
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (A.K.); (H.F.)
| | - Henrich Frielinghaus
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (A.K.); (H.F.)
| | - Mario Campana
- ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Science & Technology Facilities Council, Didcot OX11 0QX, UK;
| | | | - Sebastian Busch
- German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Hereon, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (N.Z.); (G.M.)
| | - Jean-François Moulin
- German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Hereon, Lichtenbergstr. 1, 85748 Garching bei München, Germany; (N.Z.); (G.M.)
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13
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Patel P, Santo KP, Burgess S, Vishnyakov A, Neimark AV. Stability of Lipid Coatings on Nanoparticle-Decorated Surfaces. ACS NANO 2020; 14:17273-17284. [PMID: 33226210 DOI: 10.1021/acsnano.0c07298] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Lipid membranes supported on solid surfaces and nanoparticles find multiple applications in industrial and biomedical technologies. Here, we explore in silico the mechanisms of the interactions of lipid membranes with nanostructured surfaces with deposited nanoparticles and explain the characteristic particle size dependence of the uniformity and stability of lipid coatings observed in vitro. Simulations are performed to demonstrate the specifics of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid membrane adhesion to hydrophilic and hydrophobic nanoparticles ranging in size from 1.5 to 40 nm using an original coarse-grained molecular dynamics model with implicit solvent and large simulation boxes (scales up to 280 × 154 × 69 nm3). We find that one of the major factors that affects the uniformity and stability of lipid coatings is the disjoining pressure in the water hydration layer formed between the lipid membrane and hydrophilic solid surface. This effect is accounted for by introducing a special long-range lipid-solid interaction potential that mimics the effects of the disjoining pressure in thin water layers. Our simulations reveal the physical mechanisms of interactions of lipid bilayers with solid surfaces that are responsible for the experimentally observed nonmonotonic particle size dependence of the uniformity and stability of lipid coatings: particles smaller than the hydration layer thickness (<2-3 nm) or larger than ∼20 nm are partially or fully enfolded by a lipid bilayer, whereas particles of the intermediate size (5-20 nm) cause membrane perforation and pore formation. In contrast, hydrophobic nanoparticles, which repel the hydration layer, tend to be encapsulated within the hydrophobic interior of the membrane and coated by the lipid monolayer. The proposed model can be further extended and applied to a wide class of systems comprising nanoparticles and nanostructured substrates interacting with lipid and surfactant bilayers and monolayers.
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Affiliation(s)
- Parva Patel
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Kolattukudy P Santo
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Sean Burgess
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Aleksey Vishnyakov
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
- Skolkovo Institute of Technology, Moscow 143005, Russia
| | - Alexander V Neimark
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
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Formation of Uni-Lamellar Vesicles in Mixtures of DPPC with PEO-b-PCL Amphiphilic Diblock Copolymers. Polymers (Basel) 2020; 13:polym13010004. [PMID: 33375022 PMCID: PMC7792791 DOI: 10.3390/polym13010004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/18/2020] [Accepted: 12/18/2020] [Indexed: 12/19/2022] Open
Abstract
The ability of mixtures of 1.2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and the amphiphilic diblock copolymers poly (ethylene oxide)-block-poly(ε-caprolactone) (PEO-b-PCL) to stabilize uni-lamellar nano-vesicles is reported. Small angle neutron scattering (SANS) is used to define their size distribution and bilayer structure and resolve the copresence of aggregates and clusters in solution. The vesicles have a broad size distribution which is compatible with bilayer membranes of relatively low bending stiffness. Their mean diameter increases moderately with temperature and their number density and mass is higher in the case of the diblock copolymer with the larger hydrophobic block. Bayesian analysis is performed in order to justify the use of the particular SANS fitting model and confirm the reliability of the extracted parameters. This study shows that amphiphilic block copolymers can be effectively used to prepare mixed lipid-block copolymer vesicles with controlled lamellarity and a significant potential as nanocarriers for drug delivery.
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15
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Papagiannopoulos A, Pippa N, Demetzos C, Pispas S, Radulescu A. Lamellarity and size distributions in mixed DPPC/amphiphilic poly(2-oxazoline) gradient copolymer vesicles and their temperature response. Chem Phys Lipids 2020; 234:105008. [PMID: 33181095 DOI: 10.1016/j.chemphyslip.2020.105008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/23/2020] [Accepted: 11/04/2020] [Indexed: 10/23/2022]
Abstract
Mixed liposomes of dipalmitoylphosphatidylcholine (DPPC) and gradient (pseudodiblock) poly(2-methyl-2-oxazoline)-grad-poly(2-phenyl-2-oxazoline) (MPOx) copolymers are investigated by small angle neutron scattering (SANS). All experimental data, from different phospholipid-copolymer compositions, concentrations and temperatures are fitted with one model. This model allows the determination of the separate contributions from vesicular populations of different lamellarity and size. MPOx copolymers are proved to modify both the size and lamellarity of DPPC liposomes. The gradient copolymer with higher hydrophilic content induces shrinkage of the uni- and bi-lamellar DPPC vesicles. The copolymer with lower hydrophilic content causes dramatic changes on the lamellarity of DPPC vesicles by the formation of hexa-lamellar vesicles. The tendency of multi-lamellar vesicles to transform into uni-lamellar ones as temperature increases is more pronounced in the presence of the copolymers. These findings may have direct implications on the drug loading and release properties of liposomes and their interactions with cells.
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Affiliation(s)
- Aristeidis Papagiannopoulos
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635, Athens, Greece.
| | - Natassa Pippa
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635, Athens, Greece; Department of Pharmaceutical Technology, Faculty of Pharmacy, Panepistimioupolis Zografou 15771, National and Kapodistrian University of Athens, Athens, Greece
| | - Costas Demetzos
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Panepistimioupolis Zografou 15771, National and Kapodistrian University of Athens, Athens, Greece
| | - Stergios Pispas
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635, Athens, Greece
| | - Aurel Radulescu
- Jülich Centre for Neutron Science JCNS Forschungszentrum Jülich GmbH, Outstation at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstraße 1, 85747 Garching, Germany
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16
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Benedetti F, Fu L, Thalmann F, Charitat T, Rubin A, Loison C. Coarse-Grain Simulations of Solid Supported Lipid Bilayers with Varying Hydration Levels. J Phys Chem B 2020; 124:8287-8298. [DOI: 10.1021/acs.jpcb.0c03913] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Florian Benedetti
- Institut Lumière Matière, University of Lyon, Université Claude Bernard Lyon 1, CNRS, F-69622, Villeurbanne, France
| | - Li Fu
- Institut Charles Sadron, Université de Strasbourg, CNRS, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
| | - Fabrice Thalmann
- Institut Charles Sadron, Université de Strasbourg, CNRS, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
| | - Thierry Charitat
- Institut Charles Sadron, Université de Strasbourg, CNRS, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
| | - Anne Rubin
- Institut Charles Sadron, Université de Strasbourg, CNRS, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
| | - Claire Loison
- Institut Lumière Matière, University of Lyon, Université Claude Bernard Lyon 1, CNRS, F-69622, Villeurbanne, France
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Abstract
Over the last 10 years, neutron reflectometry (NR) has emerged as a powerful technique for the investigation of biologically relevant thin films. The great advantage of NR with respect to many other surface-sensitive techniques is its sub-nanometer resolution that enables structural characterizations at the molecular level. In the case of bio-relevant samples, NR is non-destructive and can be used to probe thin films at buried interfaces or enclosed in bulky sample environment equipment. Moreover, recent advances in biomolecular deutera-tion enabled new labeling strategies to highlight certain structural features and to resolve with better accuracy the location of chemically similar molecules within a thin film.
In this chapter I will describe some applications of NR to bio-relevant samples and discuss some of the data analysis approaches available for biological thin films. In particular, examples on the structural characterization of biomembranes, protein films and protein-lipid interactions will be described.
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18
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Skoda MW. Recent developments in the application of X-ray and neutron reflectivity to soft-matter systems. Curr Opin Colloid Interface Sci 2019. [DOI: 10.1016/j.cocis.2019.03.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Rondelli V, Cola ED, Koutsioubas A, Alongi J, Ferruti P, Ranucci E, Brocca P. Mucin Thin Layers: A Model for Mucus-Covered Tissues. Int J Mol Sci 2019; 20:E3712. [PMID: 31362433 PMCID: PMC6695901 DOI: 10.3390/ijms20153712] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/24/2019] [Accepted: 07/26/2019] [Indexed: 12/31/2022] Open
Abstract
The fate of macromolecules of biological or pharmacological interest that enter the mucus barrier is a current field of investigation. Studies of the interaction between the main constituent of mucus, mucins, and molecules involved in topical transmucoidal drug or gene delivery is a prerequisite for nanomedicine design. We studied the interaction of mucin with the bio-inspired arginine-derived amphoteric polymer d,l-ARGO7 by applying complementary techniques. Small angle X-ray scattering in bulk unveiled the formation of hundreds of nanometer-sized clusters, phase separated from the mucin mesh. Quartz microbalance with dissipation and neutron reflectometry measurements on thin mucin layers deposited on silica supports highlighted the occurrence of polymer interaction with mucin on the molecular scale. Rinsing procedures on both experimental set ups showed that interaction induces alteration of the deposited hydrogel. We succeeded in building up a new significant model for epithelial tissues covered by mucus, obtaining the deposition of a mucin layer 20 Å thick on the top of a glycolipid enriched phospholipid single membrane, suitable to be investigated by neutron reflectometry. The model is applicable to unveil the cross structural details of mucus-covered epithelia in interaction with macromolecules within the Å discreteness.
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Affiliation(s)
- Valeria Rondelli
- Department of Medical Biotechnologies and Translational Medicine, Università degli Studi di Milano, L.I.T.A., Via F.lli Cervi 93, 20090 Segrate, Italy.
| | - Emanuela Di Cola
- Department of Medical Biotechnologies and Translational Medicine, Università degli Studi di Milano, L.I.T.A., Via F.lli Cervi 93, 20090 Segrate, Italy
| | - Alexandros Koutsioubas
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstrasse 1, 85748 Garching, Germany
| | - Jenny Alongi
- Department of Chemistry, Università degli Studi di Milano, Via Camillo Golgi 19, 20133 Milano, Italy
| | - Paolo Ferruti
- Department of Chemistry, Università degli Studi di Milano, Via Camillo Golgi 19, 20133 Milano, Italy
| | - Elisabetta Ranucci
- Department of Chemistry, Università degli Studi di Milano, Via Camillo Golgi 19, 20133 Milano, Italy
| | - Paola Brocca
- Department of Medical Biotechnologies and Translational Medicine, Università degli Studi di Milano, L.I.T.A., Via F.lli Cervi 93, 20090 Segrate, Italy
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20
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Koutsioubas A. Model-independent recovery of interfacial structure from multi-contrast neutron reflectivity data. J Appl Crystallogr 2019; 52:538-547. [PMID: 31236091 PMCID: PMC6557181 DOI: 10.1107/s1600576719003534] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 03/13/2019] [Indexed: 11/22/2022] Open
Abstract
An indirect Fourier transform/simulated annealing method exploits the information content of multiple solvent contrast neutron reflectivity data and permits the model-independent recovery of interfacial structure at the air/liquid and solid/liquid interface. Neutron specular reflectivity at soft interfaces provides sub-nanometre information concerning the molecular distribution of thin films, while the application of contrast variation can highlight the scattering from different parts of the system and lead to an overall reduction in fitting ambiguity. Traditional modelling approaches involve the construction of a trial scattering length density profile based on initial speculation and the subsequent refinement of its parameters through minimization of the discrepancy between the calculated and measured reflectivity. In practice this might produce an artificial bias towards specific sets of solutions. On the other hand, direct inversion of reflectivity data, despite its ability to provide a unique solution, is subject to limitations and experimental complications. Presented here is an integrated indirect Fourier transform/simulated annealing method that, when applied to multiple solvent contrast reflectivity data and within the limits of finite spatial resolution, leads to reliable reconstructions of the interfacial structure without the need for any a priori assumptions. The generality of the method permits its straightforward application in common experimental contrast-variation investigations at the solid/liquid and air/liquid interface.
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Affiliation(s)
- Alexandros Koutsioubas
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstrasse 1, 85748 Garching, Germany
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21
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Mattauch S, Koutsioubas A, Rücker U, Korolkov D, Fracassi V, Daemen J, Schmitz R, Bussmann K, Suxdorf F, Wagener M, Kämmerling P, Kleines H, Fleischhauer-Fuß L, Bednareck M, Ossoviy V, Nebel A, Stronciwilk P, Staringer S, Gödel M, Richter A, Kusche H, Kohnke T, Ioffe A, Babcock E, Salhi Z, Bruckel T. The high-intensity reflectometer of the Jülich Centre for Neutron Science: MARIA. J Appl Crystallogr 2018; 51:646-654. [PMID: 29896056 PMCID: PMC5988004 DOI: 10.1107/s1600576718006994] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 05/08/2018] [Indexed: 11/30/2022] Open
Abstract
MARIA (magnetism reflectometer with high incident angle) is a world class vertical sample reflectometer dedicated to the investigation of thin films in the fields of magnetism, soft matter and biology. The elliptical vertically focusing guide allows one to measure small samples with a typical size of 1 × 1 cm very efficiently. The double-bounce polarizer and the in situ pumped 3He SEOP (spin-exchange optical pumping) neutron spin filter cell for analysing the polarization of the reflected neutron beam can be moved into the beam in seconds. The polarized flux of MARIA amounts to 5 × 107 n (s cm2)-1 at the sample position with a horizontally collimated beam of 3 mrad, a wavelength of λ = 4.5 Å and a wavelength resolution of Δλ/λ = 10%. In the non-polarized mode a flux of 1.2 × 108 n (s cm2)-1 is achieved in this configuration. MARIA is also capable of grazing-incidence small-angle neutron scattering measurements, using a pinhole collimation with two four-segment slits and an absorber that prevents the focusing of the elliptical guide in the vertical direction.
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Affiliation(s)
- Stefan Mattauch
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Alexandros Koutsioubas
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Ulrich Rücker
- Jülich Centre for Neutron Science JCNS and Peter Grünberg Institut PGI, JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Denis Korolkov
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | | | - Jos Daemen
- ZEA-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Ralf Schmitz
- ZEA-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Klaus Bussmann
- Jülich Centre for Neutron Science JCNS and Peter Grünberg Institut PGI, JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Frank Suxdorf
- ZEA-2, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | | | | | - Harald Kleines
- ZEA-2, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | | | | | - Vladimir Ossoviy
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Andreas Nebel
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Peter Stronciwilk
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Simon Staringer
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Marko Gödel
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Alfred Richter
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Harald Kusche
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Thomas Kohnke
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Alexander Ioffe
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Earl Babcock
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Zahir Salhi
- Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Thomas Bruckel
- Jülich Centre for Neutron Science JCNS and Peter Grünberg Institut PGI, JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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Vitiello G, Musumeci D, Koutsioubas A, Paduano L, Montesarchio D, D'Errico G. Ionophores at work: Exploring the interaction of guanosine-based amphiphiles with phospholipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2392-2401. [DOI: 10.1016/j.bbamem.2017.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 08/31/2017] [Accepted: 09/05/2017] [Indexed: 01/21/2023]
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Koutsioubas A, Appavou MS, Lairez D. Time-Resolved Neutron Reflectivity during Supported Membrane Formation by Vesicle Fusion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:10598-10605. [PMID: 28872877 DOI: 10.1021/acs.langmuir.7b02459] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The formation of supported lipid bilayers (SLB) on hydrophilic substrates through the method of unilamelar vesicle fusion is used routinely in a wide range of biophysical studies. In an effort to control and better understand the fusion process on the substrate, many experimental studies employing different techniques have been devoted to the elucidation of the fusion mechanism. In the present work, we follow the kinetics of membrane formation using time-resolved (TR) neutron reflectivity, focusing on the structural changes near the solid/liquid interface. A clear indication of stacked bilayer structure is observed during the intermediate phase of SLB formation. Adsorbed lipid mass decrease is also measured in the final stage of the process. We have found that it is essential for the analysis of the experimental results to treat the shape of adsorbed lipid vesicles on an attractive substrate theoretically. The overall findings are discussed in relation to proposed fusion mechanisms from the literature, and we argue that our observations favor a model involving enhanced adhesion of incoming vesicles on the edges of already-formed bilayer patches.
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Affiliation(s)
- Alexandros Koutsioubas
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85748 Garching, Germany
| | - Marie-Sousai Appavou
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85748 Garching, Germany
| | - Didier Lairez
- Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA, Université Paris-Saclay , 91128 Palaiseau cedex, France
- Laboratoire Léon Brillouin, CNRS, CEA, Université Paris-Saclay , 91191 Gif-sur-Yvette cedex, France
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