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Walter V, Ruscher C, Benzerara O, Marques CM, Thalmann F. A machine learning study of the two states model for lipid bilayer phase transitions. Phys Chem Chem Phys 2020; 22:19147-19154. [DOI: 10.1039/d0cp02058c] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Machine learning algorithms can identify fluid and gel conformation states of individual lipid molecules.
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Affiliation(s)
- Vivien Walter
- Department of Chemistry
- King's College London
- London
- UK
| | - Céline Ruscher
- Stewart Blusson Quantum Matter Institute
- University of British Columbia
- Vancouver
- Canada
| | - Olivier Benzerara
- Institut Charles Sadron
- CNRS and University of Strasbourg
- F-67034 Strasbourg
- France
| | - Carlos M. Marques
- Institut Charles Sadron
- CNRS and University of Strasbourg
- F-67034 Strasbourg
- France
| | - Fabrice Thalmann
- Institut Charles Sadron
- CNRS and University of Strasbourg
- F-67034 Strasbourg
- France
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2
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Saotome K, Duong-Ly KC, Howard KP. Influenza A M2 protein conformation depends on choice of model membrane. Biopolymers 2016; 104:405-11. [PMID: 25652904 DOI: 10.1002/bip.22617] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 01/17/2015] [Accepted: 01/24/2015] [Indexed: 11/08/2022]
Abstract
While crystal and NMR structures exist of the influenza A M2 protein, there is disagreement between models. Depending on the requirements of the technique employed, M2 has been studied in a range of membrane mimetics including detergent micelles and membrane bilayers differing in lipid composition. The use of different model membranes complicates the integration of results from published studies necessary for an overall understanding of the M2 protein. Here we show using site-directed spin-label EPR spectroscopy (SDSL-EPR) that the conformations of M2 peptides in membrane bilayers are clearly influenced by the lipid composition of the bilayers. Altering the bilayer thickness or the lateral pressure profile within the bilayer membrane changes the M2 conformation observed. The multiple M2 peptide conformations observed here, and in other published studies, optimistically may be considered conformations that are sampled by the protein at various stages during influenza infectivity. However, care should be taken that the heterogeneity observed in published structures is not simply an artifact of the choice of the model membrane.
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Affiliation(s)
- Kei Saotome
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081
| | - Krisna C Duong-Ly
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081
| | - Kathleen P Howard
- Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, PA 19081
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3
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Bossa GV, Roth J, May S. Modeling Lipid-Lipid Correlations across a Bilayer Membrane Using the Quasi-chemical Approximation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:9924-9932. [PMID: 26302019 DOI: 10.1021/acs.langmuir.5b01719] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Mixed fluid-like lipid membranes exhibit interactions not only among the lipids within a given leaflet but also across the bilayer. The ensuing collective interleaflet coupling of entire membrane domains has been modeled previously using various mean-field approaches. Yet, also on the level of individual lipids have correlations across the bilayer been observed experimentally for binary mixtures of charged/uncharged lipids with mismatching combinations of short and long acyl chain lengths. The present study proposes a lattice gas model to quantify these correlations. To this end, we represent a macroscopically homogeneous lipid bilayer by two coupled two-dimensional lattice gases that we study using the quasi-chemical approximation. We demonstrate that the rationalization of previous experimental results is only possible if besides two-body lipid-lipid interactions within and across the bilayer our model also accounts for an additional multibody interaction mechanism, namely the local hydrophobic height mismatch created by pairing short and long chain lipids together. The robustness of the quasi-chemical approximation is verified by comparison with Monte Carlo simulations.
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Affiliation(s)
- Guilherme Volpe Bossa
- Department of Physics, North Dakota State University , Fargo, North Dakota 58108-6050, United States
| | - Joseph Roth
- Department of Physics, North Dakota State University , Fargo, North Dakota 58108-6050, United States
| | - Sylvio May
- Department of Physics, North Dakota State University , Fargo, North Dakota 58108-6050, United States
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4
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Hatty CR, Le Brun AP, Lake V, Clifton LA, Liu GJ, James M, Banati RB. Investigating the interactions of the 18kDa translocator protein and its ligand PK11195 in planar lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:1019-30. [PMID: 24374318 DOI: 10.1016/j.bbamem.2013.12.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/16/2013] [Accepted: 12/18/2013] [Indexed: 12/20/2022]
Abstract
The functional effects of a drug ligand may be due not only to an interaction with its membrane protein target, but also with the surrounding lipid membrane. We have investigated the interaction of a drug ligand, PK11195, with its primary protein target, the integral membrane 18kDa translocator protein (TSPO), and model membranes using Langmuir monolayers, quartz crystal microbalance with dissipation monitoring (QCM-D) and neutron reflectometry (NR). We found that PK11195 is incorporated into lipid monolayers and lipid bilayers, causing a decrease in lipid area/molecule and an increase in lipid bilayer rigidity. NR revealed that PK11195 is incorporated into the lipid chain region at a volume fraction of ~10%. We reconstituted isolated mouse TSPO into a lipid bilayer and studied its interaction with PK11195 using QCM-D, which revealed a larger than expected frequency response and indicated a possible conformational change of the protein. NR measurements revealed a TSPO surface coverage of 23% when immobilised to a modified surface via its polyhistidine tag, and a thickness of 51Å for the TSPO layer. These techniques allowed us to probe both the interaction of TSPO with PK11195, and PK11195 with model membranes. It is possible that previously reported TSPO-independent effects of PK11195 are due to incorporation into the lipid bilayer and alteration of its physical properties. There are also implications for the variable binding profiles observed for TSPO ligands, as drug-membrane interactions may contribute to the apparent affinity of TSPO ligands.
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Affiliation(s)
- Claire R Hatty
- Medical Imaging & Radiation Sciences Faculty Research Group, Faculty of Health Sciences, The University of Sydney, c/o Brain & Mind Research Institute, 94 Mallett Street, Camperdown, NSW 2050, Australia
| | - Anton P Le Brun
- Bragg Institute, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - Vanessa Lake
- Bragg Institute, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - Luke A Clifton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, UK
| | - Guo Jun Liu
- Medical Imaging & Radiation Sciences Faculty Research Group, Faculty of Health Sciences, The University of Sydney, c/o Brain & Mind Research Institute, 94 Mallett Street, Camperdown, NSW 2050, Australia; Life Sciences, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - Michael James
- Bragg Institute, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia; School of Chemistry, University of New South Wales, Kensington NSW 2052, Australia
| | - Richard B Banati
- Medical Imaging & Radiation Sciences Faculty Research Group, Faculty of Health Sciences, The University of Sydney, c/o Brain & Mind Research Institute, 94 Mallett Street, Camperdown, NSW 2050, Australia; Life Sciences, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia.
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5
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Cheng KH, Virtanen J, Somerharju P. Calorimetric behavior of phosphatidylcholine/phosphatidylethanolamine bilayers is compatible with the superlattice model. J Phys Chem B 2012; 116:1802-11. [PMID: 22251448 DOI: 10.1021/jp2078488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Differential scanning calorimetry was used to study the phase behavior of binary lipid bilayers consisting of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of varying acyl chain length. A two-state transition model was used to resolve the individual transition components, and the two-state transition enthalpy, the relative enthalpy, and the transition temperature of each component were plotted as a function of composition. Intriguingly, abrupt changes in these thermodynamic parameters were observed at or close to many "critical" X(PE) values predicted by the superlattice model proposing that phospholipids with different headgroups tend to adopt regular rather than random lateral distributions. Statistical analysis indicated that the agreement between the observed and predicted "critical" compositions is highly significant. Accordingly, these data provide strong evidence that the molecules in PC/PE bilayers tend to adopt regular, superlattice-like lateral arrangements, which could be involved in the regulation of the lipid compositions of biological membranes.
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Affiliation(s)
- Kwan Hon Cheng
- Department of Physics and Astronomy, Trinity University, San Antonio, Texas 78212-7200, USA.
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Mondal Roy S, Sarkar M. Effect of lipid molecule headgroup mismatch on non steroidal anti-inflammatory drugs induced membrane fusion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:15054-15064. [PMID: 21999838 DOI: 10.1021/la2030186] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Membrane fusion is an essential process guiding many important biological events, which most commonly requires the aid of proteins and peptides as fusogenic agents. Small drug induced fusion at low drug concentration is a rare event. Only three drugs, namely, meloxicam (Mx), piroxicam (Px), and tenoxicam (Tx), belonging to the oxicam group of non steroidal anti-inflammatory drugs (NSAIDs) have been shown by us to induce membrane fusion successfully at low drug concentration. A better elucidation of the mechanism and the effect of different parameters in modulating the fusion process will allow the use of these common drugs to induce and control membrane fusion in various biochemical processes. In this study, we monitor the effect of lipid headgroup size mismatch in the bilayer on oxicam NSAIDs induced membrane fusion, by introducing dimyristoylphosphatidylethanolamine (DMPE) in dimyristoylphosphatidylcholine (DMPC) small unilamellar vesicles (SUVs). Such headgroup mismatch affects various lipid parameters which includes inhibition of trans-bilayer motion, domain formation, decrease in curvature, etc. Changes in various lipidic parameters introduce defects in the membrane bilayer and thereby modulate membrane fusion. SUVs formed by DMPC with increasing DMPE content (10, 20, and 30 mol %) were used as simple model membranes. Transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) were used to characterize the DMPC-DMPE mixed vesicles. Fluorescence assays were used to probe the time dependence of lipid mixing, content mixing, and leakage and also used to determine the partitioning of the drugs in the membrane bilayer. How the inhibition of trans-bilayer motion, heterogeneous distribution of lipids, decrease in vesicle curvature, etc., arising due to headgroup mismatch affect the fusion process has been isolated and identified here. Mx amplifies these effects maximally followed by Px and Tx. This has been correlated to the enhanced partitioning of the hydrophobic Mx compared to the more hydrophilic Px and Tx in the mixed bilayer.
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Affiliation(s)
- Sutapa Mondal Roy
- Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata-700064, India
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7
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Wolff J, Marques CM, Thalmann F. Thermodynamic approach to phase coexistence in ternary phospholipid-cholesterol mixtures. PHYSICAL REVIEW LETTERS 2011; 106:128104. [PMID: 21517355 DOI: 10.1103/physrevlett.106.128104] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Indexed: 05/30/2023]
Abstract
We introduce a simple and predictive model for determining the phase stability of ternary phospholipid-cholesterol mixtures. Assuming that competition between the liquid and gel order of the phospholipids is the main driving force behind lipid segregation, we derive a Gibbs free energy of mixing, based on the thermodynamic properties of the lipids main transition. A numerical approach was devised that enables the fast and efficient determination of the ternary diagrams associated with our Gibbs free energy. The computed phase coexistence diagram of DOPC/DPPC/cholesterol reproduces well-known features for this system at 10 °C, as well as its evolution with temperature.
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Affiliation(s)
- J Wolff
- Institut Charles Sadron, Université de Strasbourg, CNRS UPR 22, 23 rue du Loess, Strasbourg Cedex, F-67037, France
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Bloom M, Evans E, Mouritsen OG. Physical properties of the fluid lipid-bilayer component of cell membranes: a perspective. Q Rev Biophys 1991; 24:293-397. [PMID: 1749824 DOI: 10.1017/s0033583500003735] [Citation(s) in RCA: 617] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The motivation for this review arises from the conviction that, as a result of the mass of experimental data and observations collected in recent years, the study of the physical properties of membranes is now entering a new stage of development. More and more, experiments are being designed to answer specific, detailed questions about membranes which will lead to a quantitative understanding of the way in which the physical properties of membranes are related to and influence their biological function.
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Affiliation(s)
- M Bloom
- Department of Physics, University of British Columbia, Vancouver, Canada
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Dörfler HD, Brezesinski G, Miethe P. Phase diagrams of pseudo-binary phospholipid systems. I. Influence of the chain length differences on the miscibility properties of cephaline/cephaline/water systems. Chem Phys Lipids 1988; 48:245-54. [PMID: 3242952 DOI: 10.1016/0009-3084(88)90094-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The miscibility properties of homologous cephalines (PEs) were studied by means of differential scanning calorimetry (DSC). The phase diagrams of 5 pseudo-binary cephaline/cephaline/water systems (50% water) are discussed. In the high temperature L alpha-phase, all the homologous cephalines of fatty acid chain length from C = 12 to C = 18 were completely miscible. On the other hand in the low temperature L beta-phase, a miscibility gap occurred in dependence on the differences of the acyl chain lengths. Further, a distinct succession of the phase diagram types was observed according to increasing chain length differences of the PEs: complete miscibility (systems di-(C12:O)-PE/di-(C14:O)-PE/H2O; di-(C14:O)-PE/di-C(16:O)-PE/H2O)----peritectic mixing behaviour (systems di-(C12:O)-PE/di-(C16:O)-PE/H2O; di-(C14:O)-PE/di-(C18:O)-PE/H2O)----eutectic mixing behaviour (system di-(C12:O)-PE/di-(C18:O)-PE/H2O). The change in the type of phase diagram from azeotropic to semi-azeotropic and from semi-azeotropic to eutectic is interpreted by means of the Landau theory.
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Affiliation(s)
- H D Dörfler
- Sektion Chemie der Technischen Universität Dresden, G.D.R
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Tolgyesi F, Monticelli G. pH and chain length dependence of phosphatidic acid phase transition parameters. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/0302-4598(87)80058-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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11
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Small angle X-ray and dielectric data of soybean-phosphatidylcholine Phospholipon� 100. Colloid Polym Sci 1985. [DOI: 10.1007/bf01419894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Sugár IP, Monticelli G. Interrelationships between the phase diagrams of the two-component phospholipid bilayers. Biophys J 1985; 48:283-8. [PMID: 4052562 PMCID: PMC1329319 DOI: 10.1016/s0006-3495(85)83781-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Basic relationships between the phase diagrams, previously considered independent of each other, are described. Phase diagrams of two-component phosphatidylcholine/phosphatidylcholine (PC/PC), phosphatidylethanolamine/phosphatidylethanolamine (PE/PE), and PC/PE lipid membranes are systematically investigated by means of the Landau theory. While gradually changing the chain length of one of the components, a characteristic peritectic-miscible-azeotropic-semiazeotropic-eutectic (P-M-A-S-E) series of the phase diagram was found in the PC/PE system and a peritectic-miscible-one-component-miscible-peritectic (P-M-O-M-P) series was found in the PC/PC and PE/PE systems. These serial catastrophic changes in the phase diagrams could be explained by the fusion and birth of the mixed phase regions in the phase diagram. Finally when we constructed the superdiagrams, we obtained all of the possible series of the phase diagrams in a wide class of the two-component mixtures. Moreover, one can predict the type of the phase diagram when the components r and p contain equal-length saturated hydrocarbon chains. Depending on the relationships between the chain lengths (L, Lp) and that on the phase transition temperatures of the pure components (Tr, Tp), the system is: miscible (M), if 0 < Tr(L) - Tp(L) < 5 degrees C and L -Lp > 0, azeotropic (A), if 0 < T,(L) - Tp(L) < 5 degrees C and L -Lp < 0, peritectic (P), if T,(L) - Tp(L) > 40 degrees C and L -Lp - 0, eutectic (E), if Tr(L) - Tp(L) >40 degrees C and L - Lp <0,while it is M or P if 5 degrees C< Tr(L) - Tp(L) <40 degrees C and L - Lp>-0,and E,S,or Aif 5 degrees C < Tr(L) - Tp(L) < 40 degrees C and L,-Lp < 0.
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