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Uyama M, Hama T. Controlling the formation of ionic complex vesicles through double-tailed surfactants. Int J Cosmet Sci 2024. [PMID: 38802988 DOI: 10.1111/ics.12973] [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: 02/01/2024] [Revised: 04/04/2024] [Accepted: 04/15/2024] [Indexed: 05/29/2024]
Abstract
OBJECTIVE Liposomes are often used in cosmetics since they are naturally derived and have excellent texture enhancing capabilities. However, when preparing them by using phospholipids with unsaturated acyl groups, they easily suffer from oxidative degradation. Accordingly, hydrogenated phospholipids are preferred, however, it is difficult to prepare stable liposomes due to its high gel-liquid crystalline phase transition temperature. On the other hand, although dialkyl dimethyl ammonium type cationic surfactants are widely known to form vesicles, they have rarely been used for skincare products except for water-in-oil type emulsion creams stabilized by organically modified clay minerals. We decided to overcome all of the problems above through ionic complex vesicles formed by double-tailed cationic and anionic surfactants. METHODS Distearyl dimethyl ammonium chloride (DSAC) and sodium dilauramidoglutamide lysine (DLGL) were selected as cationic and anionic surfactants, respectively. Differential scanning calorimetry (DSC) and small- and wide-angle X-ray scattering (SWAXS) measurements were performed to confirm the DSAC/DLGL/water ternary phase diagram. Newly developed ionic complex vesicle formation was confirmed by cryogenic transmission electron microscopy (cryo-TEM). The adsorbed cosmetic film structure on the skin in vivo was evaluated through the polarized infrared external reflection (PIR-ER). Finally, a cosmetic lotion formula was developed and the vesicle size was determined by dynamic light scattering (DLS). RESULTS DSC and SWAXS data indicated that stable vesicles could be obtained at a molar ratio of DLGL to DSAC = 6:4. At this molar ratio, multi lamellar vesicles with diameters less than 100 nm were observed through cryo-TEM. PIR-ER data revealed that the developed vesicles formed a highly perpendicular orientation to the human skin surface. We have succeeded in formulating a cosmetic lotion containing developed vesicles with a mean diameter of 63.2 nm, which was stable over 1 month at 0, 37, and 50°C. CONCLUSIONS Our newly developed vesicles can be easily obtained through a coagulation process. Also, the adsorbed film structure supported by PIR-ER experiments implies that the developed lotion has an excellent texture that is the same as cosmetic lotions containing liposomes. Therefore, it's possible that this ionic complex vesicle could take the place of liposomes.
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Affiliation(s)
- Makoto Uyama
- Shiseido Co., Ltd., MIRAI Technology Institute, Yokohama, Japan
| | - Tetsuya Hama
- Komaba Institute for Science, The University of Tokyo, Tokyo, Japan
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2
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Martin A, Jemmett PN, Howitt T, Wood MH, Burley AW, Cox LR, Dafforn TR, Welbourn RJL, Campana M, Skoda MW, Thompson JJ, Hussain H, Rawle JL, Carlà F, Nicklin CL, Arnold T, Horswell SL. Effect of Anionic Lipids on Mammalian Plasma Cell Membrane Properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:2676-2691. [PMID: 36757323 PMCID: PMC9948536 DOI: 10.1021/acs.langmuir.2c03161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 01/19/2023] [Indexed: 06/18/2023]
Abstract
The effect of lipid composition on models of the inner leaflet of mammalian cell membranes has been investigated. Grazing incidence X-ray diffraction and X-ray and neutron reflectivity have been used to characterize lipid packing and solvation, while electrochemical and infrared spectroscopic methods have been employed to probe phase behavior in an applied electric field. Introducing a small quantity of the anionic lipid dimyristoylphosphatidylserine (DMPS) into bilayers of zwitterionic dimyristoylphosphatidylethanolamine (DMPE) results in a significant change in the bilayer response to an applied field: the tilt of the hydrocarbon chains increases before returning to the original tilt angle on detachment of the bilayer. Equimolar mixtures, with slightly closer chain packing, exhibit a similar but weaker response. The latter also tend to incorporate more solvent during this electrochemical phase transition, at levels similar to those of pure DMPS. Reflectivity measurements reveal greater solvation of lipid layers for DMPS > 30 mol %, matching the greater propensity for DMPS-rich bilayers to incorporate water. Taken together, the data indicate that the range of 10-35 mol % DMPS provides optimum bilayer properties (in flexibility and function as a barrier), which may explain why the DMPS content of cell membranes tends to be found within this range.
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Affiliation(s)
- Alexandra
L. Martin
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Philip N. Jemmett
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Thomas Howitt
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Mary H. Wood
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Andrew W. Burley
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Liam R. Cox
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Timothy R. Dafforn
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Rebecca J. L. Welbourn
- ISIS
Pulsed Neutron and Muon Source, Science
and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, OxfordshireOX11 0QX, U.K.
| | - Mario Campana
- ISIS
Pulsed Neutron and Muon Source, Science
and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, OxfordshireOX11 0QX, U.K.
| | - Maximilian W.
A. Skoda
- ISIS
Pulsed Neutron and Muon Source, Science
and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, OxfordshireOX11 0QX, U.K.
| | - Joseph J. Thompson
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
| | - Hadeel Hussain
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
| | - Jonathan L. Rawle
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
| | - Francesco Carlà
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
| | - Christopher L. Nicklin
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
| | - Thomas Arnold
- ISIS
Pulsed Neutron and Muon Source, Science
and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, OxfordshireOX11 0QX, U.K.
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
- European
Spallation Source ERIC PO Box 176, SE-221 00Lund, Sweden
- Department
of Chemistry, University of Bath, Claverton Down, BathBA2 7AY, U.K.
| | - Sarah L. Horswell
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
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Ankner JF, Ashkar R, Browning JF, Charlton TR, Doucet M, Halbert CE, Islam F, Karim A, Kharlampieva E, Kilbey SM, Lin JYY, Phan MD, Smith GS, Sukhishvili SA, Thermer R, Veith GM, Watkins EB, Wilson D. Cinematic reflectometry using QIKR, the quite intense kinetics reflectometer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:013302. [PMID: 36725568 DOI: 10.1063/5.0122279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 11/14/2022] [Indexed: 06/18/2023]
Abstract
The Quite Intense Kinetics Reflectometer (QIKR) will be a general-purpose, horizontal-sample-surface neutron reflectometer. Reflectometers measure the proportion of an incident probe beam reflected from a surface as a function of wavevector (momentum) transfer to infer the distribution and composition of matter near an interface. The unique scattering properties of neutrons make this technique especially useful in the study of soft matter, biomaterials, and materials used in energy storage. Exploiting the increased brilliance of the Spallation Neutron Source Second Target Station, QIKR will collect specular and off-specular reflectivity data faster than the best existing such machines. It will often be possible to collect complete specular reflectivity curves using a single instrument setting, enabling "cinematic" operation, wherein the user turns on the instrument and "films" the sample. Samples in time-dependent environments (e.g., temperature, electrochemical, or undergoing chemical alteration) will be observed in real time, in favorable cases with frame rates as fast as 1 Hz. Cinematic data acquisition promises to make time-dependent measurements routine, with time resolution specified during post-experiment data analysis. This capability will be deployed to observe such processes as in situ polymer diffusion, battery electrode charge-discharge cycles, hysteresis loops, and membrane protein insertion into lipid layers.
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Affiliation(s)
- J F Ankner
- Second Target Station Project, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R Ashkar
- Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA
| | - J F Browning
- Neutron Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T R Charlton
- Neutron Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - M Doucet
- Neutron Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - C E Halbert
- Neutron Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - F Islam
- Neutron Technologies Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A Karim
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, USA
| | - E Kharlampieva
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - S M Kilbey
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - J Y Y Lin
- Second Target Station Project, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - M D Phan
- Neutron Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - G S Smith
- Neutron Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S A Sukhishvili
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - R Thermer
- Second Target Station Project, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - G M Veith
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E B Watkins
- Neutron Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D Wilson
- Second Target Station Project, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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4
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Cheng V, Conboy JC. Inhibitory Effect of Lanthanides on Native Lipid Flip-Flop. J Phys Chem B 2022; 126:7651-7663. [PMID: 36129784 DOI: 10.1021/acs.jpcb.2c04039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The influence of ytterbium ions (Yb3+), a commonly used paramagnetic NMR chemical shift reagent, on the physical properties and flip-flop kinetics of dipalmitoylphosphatidylcholine (DPPC) planar supported lipid bilayers (PSLBs) was investigated. Langmuir isotherm studies revealed that Yb3+ interacts strongly with the phosphate headgroup of DPPC, evidenced by the increases in shear and compression moduli. Using sum-frequency vibrational spectroscopy, changes in the acyl chain ordering and phase transition temperature were also observed, consistent with Yb3+ interacting with the phosphate headgroup of DPPC. The changes in the physical properties of the membrane were also observed to be concentration dependent, with more pronounced modification observed at low (50 μM) Yb3+ concentrations compared to 6.5 mM Tb3+, suggesting a cross-linking mechanism between adjacent DPPC lipids. Additionally, the changes in membrane packing and phase transition temperatures in the presence of Tris buffer suggested that a putative Yb(Tris)3+ complex forms that coordinates to the PC headgroup. The kinetics of DPPC flip-flop in the gel and liquid crystalline (lc) phases were substantially inhibited in the presence of Yb3+, regardless of the Yb3+ concentration. Analysis of the flip-flop kinetics under the framework of transition state theory revealed that the free energy barrier to flip-flop in both the gel and lc phases was substantial increased over a pure DPPC membrane. In the gel phase, the trend in the free energy barrier appeared to follow the trend in the shear moduli, suggesting that the Yb3+-DPPC headgroup interaction was driving the increase in the activation free energy barrier. In the lc phase, activation free energies of DPPC flip-flop in the presence of 50 μM or 6.5 mM Yb3+ were found to mirror the free energies of TEMPO-DPPC flip-flop, leading to the conclusion that the strong interaction between Yb3+ and the PC headgroup was essentially manifested as a headgroup charge modification. These studies illustrate that the presence of the lanthanide Yb3+ results in significant modification to the lipid membrane physical properties and, more importantly, results in a pronounced inhibition of native lipid flip-flop.
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Affiliation(s)
- Victoria Cheng
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - John C Conboy
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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5
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Cisse A, Matsuo T, Plazanet M, Natali F, Koza MM, Ollivier J, Bicout DJ, Peters J. The dynamical Matryoshka model: 2. Modeling of local lipid dynamics at the sub-nanosecond timescale in phospholipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183950. [PMID: 35525301 DOI: 10.1016/j.bbamem.2022.183950] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 04/06/2022] [Accepted: 04/25/2022] [Indexed: 12/12/2022]
Abstract
Biological membranes are generally formed by lipids and proteins. Often, the membrane properties are studied through model membranes formed by phospholipids only. They are molecules composed by a hydrophilic head group and hydrophobic tails, which can present a panoply of various motions, including small localized movements of a few atoms up to the diffusion of the whole lipid or collective motions of many of them. In the past, efforts were made to measure these motions experimentally by incoherent neutron scattering and to quantify them, but with upcoming modern neutron sources and instruments, such models can now be improved. In the present work, we expose a quantitative and exhaustive study of lipid dynamics on DMPC and DMPG membranes, using the Matryoshka model recently developed by our group. The model is confronted here to experimental data collected on two different membrane samples, at three temperatures and two instruments. Despite such complexity, the model describes reliably the data and permits to extract a series of parameters. The results compare also very well to other values found in the literature.
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Affiliation(s)
- Aline Cisse
- Univ. Grenoble Alpes, CNRS, LiPhy, 38000 Grenoble, France; Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, 7, France
| | - Tatsuhito Matsuo
- Univ. Grenoble Alpes, CNRS, LiPhy, 38000 Grenoble, France; Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, 7, France; Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, 2-4 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Marie Plazanet
- Univ. Grenoble Alpes, CNRS, LiPhy, 38000 Grenoble, France
| | - Francesca Natali
- Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, 7, France; CNR-IOM and INSIDE@ILL, c/o OGG, 38042 Grenoble Cedex 9, France
| | - Michael Marek Koza
- Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, 7, France
| | - Jacques Ollivier
- Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, 7, France
| | - Dominique J Bicout
- Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, 7, France; Univ. Grenoble Alpes, CNRS, Grenoble INP, VetAgro Sup, TIMC, 38000 Grenoble, France
| | - Judith Peters
- Univ. Grenoble Alpes, CNRS, LiPhy, 38000 Grenoble, France; Institut Laue-Langevin, 71 avenue des Martyrs, CS 20156, 38042 Grenoble Cedex 9, 7, France; Institut Universitaire de France, France.
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6
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Cheng V, Rallabandi R, Gorusupudi A, Lucas S, Rognon G, Bernstein PS, Rainier JD, Conboy JC. Influence of very-long-chain polyunsaturated fatty acids on membrane structure and dynamics. Biophys J 2022; 121:2730-2741. [PMID: 35711144 DOI: 10.1016/j.bpj.2022.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/24/2022] [Accepted: 06/10/2022] [Indexed: 11/30/2022] Open
Abstract
The unique attributes of very-long-chain polyunsaturated fatty acids (VLC-PUFAs), their long carbon chains (n > 24) and high degree of unsaturation, impart unique chemical and physical properties to this class of fatty acids. The changes imparted by VLC-PUFA 32:6 n-3 on lipid packing and the compression moduli of model membranes were evaluated from π-A isotherms of VLC-PUFA in 1,2-distearoyl-sn-3-glycero-phosphocholine (DSPC) lipid monolayers. To compare the attractive or repulsive forces between VLC-PUFA and DSPC lipid monolayers, the measured mean molecular areas (MMAs) were compared with the calculated MMAs of an ideal mixture of VLC-PUFA and DSPC. The presence of 0.1, 1, and 10 mol % VLC-PUFA shifted the π-A isotherm to higher MMAs of the lipids comprising the membrane and the observed positive deviations from ideal behavior of the mixed VLC-PUFA:DSPC monolayers correspond to repulsive forces between VLC-PUFAs and DSPC. The MMA of the VLC-PUFA component was estimated using the measured MMAs of DSPC of 47.1 ± 0.7 Å2/molecule, to be 15,000, 1100, and 91 Å2/molecule at 0.1, 1, and 10 mol % VLC-PUFA:DSPC mixtures, respectively. The large MMAs of VLC-PUFA suggest that the docosahexaenoic acid tail reinserts into the membrane and adopts a nonlinear structure in the membrane, which is most pronounced at 0.1 mol % VLC-PUFA. The presence of 0.1 mol % VLC-PUFA:DSPC also significantly increased the compression modulus of the membrane by 28 mN/m compared with a pure DSPC membrane. The influence of VLC-PUFA on lipid "flip-flop" was investigated by sum-frequency vibrational spectroscopy. The incorporation of 0.1 mol % VLC-PUFA increased the DSPC flip-flop rate fourfold. The fact that VLC-PUFA promotes lipid translocation is noteworthy as retinal membranes require a high influx of retinoids which may be facilitated by lipid flip-flop.
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Affiliation(s)
- Victoria Cheng
- Department of Chemistry, University of Utah, Salt Lake City, Utah
| | | | - Aruna Gorusupudi
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah
| | - Steven Lucas
- Department of Chemistry, University of Utah, Salt Lake City, Utah
| | - Gregory Rognon
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah
| | - Paul S Bernstein
- Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah
| | - Jon D Rainier
- Department of Chemistry, University of Utah, Salt Lake City, Utah
| | - John C Conboy
- Department of Chemistry, University of Utah, Salt Lake City, Utah.
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7
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Perez-Salas U, Garg S, Gerelli Y, Porcar L. Deciphering lipid transfer between and within membranes with time-resolved small-angle neutron scattering. CURRENT TOPICS IN MEMBRANES 2021; 88:359-412. [PMID: 34862031 DOI: 10.1016/bs.ctm.2021.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This review focuses on time-resolved neutron scattering, particularly time-resolved small angle neutron scattering (TR-SANS), as a powerful in situ noninvasive technique to investigate intra- and intermembrane transport and distribution of lipids and sterols in lipid membranes. In contrast to using molecular analogues with potentially large chemical tags that can significantly alter transport properties, small angle neutron scattering relies on the relative amounts of the two most abundant isotope forms of hydrogen: protium and deuterium to detect complex membrane architectures and transport processes unambiguously. This review discusses advances in our understanding of the mechanisms that sustain lipid asymmetry in membranes-a key feature of the plasma membrane of cells-as well as the transport of lipids between membranes, which is an essential metabolic process.
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Affiliation(s)
- Ursula Perez-Salas
- Physics Department, University of Illinois at Chicago, Chicago, IL, United States.
| | - Sumit Garg
- Physics Department, University of Illinois at Chicago, Chicago, IL, United States
| | - Yuri Gerelli
- Department of Life and Environmental Sciences, Universita` Politecnica delle Marche, Ancona, Italy
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Abstract
Cell membranes - primarily composed of lipids, sterols, and proteins - form a dynamic interface between living cells and their environment. They act as a mechanical barrier around the cell while selectively facilitating material transport, signal transduction, and various other functions necessary for the cell viability. The complex functionality of cell membranes and the hierarchical motions and responses they exhibit demand a thorough understanding of the origin of different membrane dynamics and how they are influenced by molecular additives and environmental cues. These dynamic modes include single-molecule diffusion, thermal fluctuations, and large-scale membrane deformations, to name a few. This review highlights advances in investigating structure-driven dynamics associated with model cell membranes, with a particular focus on insights gained from neutron scattering and spectroscopy experiments. We discuss the uniqueness of neutron contrast variation and its remarkable potential in probing selective membrane structure and dynamics on spatial and temporal scales over which key biological functions occur. We also present a summary of current and future opportunities in synergistic combinations of neutron scattering with molecular dynamics (MD) simulations to gain further understanding of the molecular mechanisms underlying complex membrane functions.
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Affiliation(s)
- Sudipta Gupta
- Department of Physics, Virginia Tech, Blacksburg, VA 24061, USA. and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA 24061, USA
| | - Rana Ashkar
- Department of Physics, Virginia Tech, Blacksburg, VA 24061, USA. and Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA 24061, USA
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Qian S, Sharma VK, Clifton LA. Understanding the Structure and Dynamics of Complex Biomembrane Interactions by Neutron Scattering Techniques. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:15189-15211. [PMID: 33300335 DOI: 10.1021/acs.langmuir.0c02516] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The membrane is one of the key structural materials of biology at the cellular level. Composed predominantly of a bilayer of lipids with embedded and bound proteins, it defines the boundaries of the cell and many organelles essential to life and therefore is involved in almost all biological processes. Membrane-specific interactions, such as drug binding to a membrane receptor or the interactions of an antimicrobial compound with the lipid matrix of a pathogen membrane, are of interest across the scientific disciplines. Herein we present a review, aimed at nonexperts, of the major neutron scattering techniques used in membrane studies: small-angle neutron scattering, neutron membrane diffraction, neutron reflectometry, quasielastic neutron scattering, and neutron spin echo. Neutron scattering techniques are well suited to studying biological membranes. The nondestructive nature of cold neutrons means that samples can be measured for long periods without fear of beam damage from ultraviolet, electron, or X-ray radiation, and neutron beams are highly penetrating, thus offering flexibility in samples and sample environments. Most important is the strong difference in neutron scattering lengths between the two most abundant forms of hydrogen, protium and deuterium. Changing the relative amounts of protium/deuterium in a sample allows the production of a series of neutron scattering data sets, enabling the observation of differing components within complex membrane architectures. This approach can be as simple as using the naturally occurring neutron contrast between different biomolecules to study components in a complex by changing the solution H2O/D2O ratio or as complex as selectively labeling individual components with hydrogen isotopes. This review presents an overview of each experimental technique with the neutron instrument configuration, related sample preparation and sample environment, and data analysis, highlighted by a special emphasis on using prominent neutron contrast to understand structure and dynamics. This review gives researchers a practical introduction to the often enigmatic suite of neutron beamlines, thereby lowering the barrier to taking advantage of these large-facility techniques to achieve new understandings of membranes and their interactions with other molecules.
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Affiliation(s)
- Shuo Qian
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Veerendra Kumar Sharma
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Luke A Clifton
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, U.K. OX11 0QX
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10
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Porcar L, Gerelli Y. On the lipid flip-flop and phase transition coupling. SOFT MATTER 2020; 16:7696-7703. [PMID: 32789357 DOI: 10.1039/d0sm01161d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We measured the passive lipid flip-flop of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) in solid supported lipid bilayers across their main gel to fluid (Lβ → Lα) phase transition. By performing time and temperature resolved neutron reflectometry experiments, we demonstrated that asymmetric systems prepared in the gel phase are stable for at least 24 hours. Lipid flip-flop was found to be intrinsically linked to the amount of lipid molecules in the fluid phase. Moreover, the increase of this amount during the broad phase transition was found to be the main key factor for the timing of the flip-flop process. By measuring different temperature scan rate, we could demonstrate that, in the case of supported bilayers and for the temperature investigated, the lipid flip flop is characterised by an activation energy of 50 kJ mol-1 and a timescale on the order of few hours. Our results demonstrate the origin on the discrepancies between passive flip-flop in bulk systems and at interfaces.
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Affiliation(s)
- Lionel Porcar
- Institut Laue-Langevin, avenue des Martyrs, 38000 Grenoble, France
| | - Yuri Gerelli
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy.
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11
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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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12
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Liu Y, Kelley EG, Batchu KC, Porcar L, Perez-Salas U. Creating Asymmetric Phospholipid Vesicles via Exchange With Lipid-Coated Silica Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:8865-8873. [PMID: 32623897 PMCID: PMC7899156 DOI: 10.1021/acs.langmuir.0c01188] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Recently, effort has been placed into fabricating model free-floating asymmetric lipid membranes, such as asymmetric vesicles. Here, we report on the use of lipid-coated silica nanoparticles to exchange lipids with initially symmetric vesicles to generate composition-controlled asymmetric vesicles. Our method relies on the simple and natural exchange of lipids between membranes through an aqueous medium. Using a selected temperature, time, and ratio of lipid-coated silica nanoparticles to vesicles, we produced a desired highly asymmetric leaflet composition. At this point, the silica nanoparticles were removed by centrifugation, leaving the asymmetric vesicles in solution. In the present work, the asymmetric vesicles were composed of isotopically distinct dipalmitoylphosphatidylcholine lipids. Lipid asymmetry was detected by both small-angle neutron scattering (SANS) and proton nuclear magnetic resonance (1H NMR). The rate at which the membrane homogenizes at 75 °C was also assessed.
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Affiliation(s)
- Yangmingyue Liu
- Physics Department, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Elizabeth G Kelley
- NIST Center For Neutron Research, Gaithersburg, Maryland 20889, United States
| | - Krishna C Batchu
- Large Scale Structure Group, Institut Laue-Langevin, Grenoble F-38042, France
| | - Lionel Porcar
- Large Scale Structure Group, Institut Laue-Langevin, Grenoble F-38042, France
| | - Ursula Perez-Salas
- Physics Department, University of Illinois at Chicago, Chicago, Illinois 60607, United States
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13
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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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14
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Clifton LA, Campbell RA, Sebastiani F, Campos-Terán J, Gonzalez-Martinez JF, Björklund S, Sotres J, Cárdenas M. Design and use of model membranes to study biomolecular interactions using complementary surface-sensitive techniques. Adv Colloid Interface Sci 2020; 277:102118. [PMID: 32044469 DOI: 10.1016/j.cis.2020.102118] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/24/2020] [Accepted: 01/29/2020] [Indexed: 01/07/2023]
Abstract
Cellular membranes are complex structures and simplified analogues in the form of model membranes or biomembranes are used as platforms to understand fundamental properties of the membrane itself as well as interactions with various biomolecules such as drugs, peptides and proteins. Model membranes at the air-liquid and solid-liquid interfaces can be studied using a range of complementary surface-sensitive techniques to give a detailed picture of both the structure and physicochemical properties of the membrane and its resulting interactions. In this review, we will present the main planar model membranes used in the field to date with a focus on monolayers at the air-liquid interface, supported lipid bilayers at the solid-liquid interface and advanced membrane models such as tethered and floating membranes. We will then briefly present the principles as well as the main type of information on molecular interactions at model membranes accessible using a Langmuir trough, quartz crystal microbalance with dissipation monitoring, ellipsometry, atomic force microscopy, Brewster angle microscopy, Infrared spectroscopy, and neutron and X-ray reflectometry. A consistent example for following biomolecular interactions at model membranes is used across many of the techniques in terms of the well-studied antimicrobial peptide Melittin. The overall objective is to establish an understanding of the information accessible from each technique, their respective advantages and limitations, and their complementarity.
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Affiliation(s)
- Luke A Clifton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 OQX, United Kingdom
| | - Richard A Campbell
- Division of Pharmacy and Optometry, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Federica Sebastiani
- Department of Biomedical Science and Biofilms - Research Center for Biointerfaces, Malmö University, 20506 Malmö, Sweden
| | - José Campos-Terán
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Unidad Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe, Delegación Cuajimalpa de Morelos, 05348, Mexico; Lund Institute of advanced Neutron and X-ray Science, Lund University, Scheelevägen 19, 223 70 Lund, Sweden
| | - Juan F Gonzalez-Martinez
- Department of Biomedical Science and Biofilms - Research Center for Biointerfaces, Malmö University, 20506 Malmö, Sweden
| | - Sebastian Björklund
- Department of Biomedical Science and Biofilms - Research Center for Biointerfaces, Malmö University, 20506 Malmö, Sweden
| | - Javier Sotres
- Department of Biomedical Science and Biofilms - Research Center for Biointerfaces, Malmö University, 20506 Malmö, Sweden
| | - Marité Cárdenas
- Department of Biomedical Science and Biofilms - Research Center for Biointerfaces, Malmö University, 20506 Malmö, Sweden.
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A biophysical study of the interactions between the antimicrobial peptide indolicidin and lipid model systems. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:1355-1364. [DOI: 10.1016/j.bbamem.2019.04.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/22/2019] [Accepted: 04/07/2019] [Indexed: 12/19/2022]
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16
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Gerelli Y. Phase Transitions in a Single Supported Phospholipid Bilayer: Real-Time Determination by Neutron Reflectometry. PHYSICAL REVIEW LETTERS 2019; 122:248101. [PMID: 31322398 DOI: 10.1103/physrevlett.122.248101] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Indexed: 05/06/2023]
Abstract
Time- and temperature-resolved neutron reflectometry allowed us to perform the real-time characterization of the structural changes taking place across phase transitions in solid supported-lipid bilayers (SLBs). We identified the presence of an isothermal phase transition, characterized by a symmetrical rearrangement of lipid molecules in both bilayer leaflets, followed by the main thermotropic phase transition, and characterized by an independent melting of the two leaflets. We demonstrated that the presence of a substrate increases the enthalpy of melting by the same amount for both SLB leaflets with respect to the values reported for freestanding bilayers. These results are highly relevant for the further understanding of cooperative structural dynamics in SLBs and for the investigation of thermally activated processes such as the transmembrane lipid translocation (flip flop).
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Böhm P, Koutsioubas A, Moulin JF, Rädler JO, Sackmann E, Nickel B. Probing the Interface Structure of Adhering Cells by Contrast Variation Neutron Reflectometry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:513-521. [PMID: 30518215 DOI: 10.1021/acs.langmuir.8b02228] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Cellular adhesion is a central element in tissue mechanics, biological cell-cell signaling, and cell motility. In this context, the cell-substrate distance has been investigated in the past by studying natural cells and biomimetic cell models adhering on solid substrates. The amount of water in the membrane substrate gap, however, is difficult to determine. Here, we present a neutron reflectivity (NR) structural study of confluent epithelial cell monolayers on silicon substrates. In order to ensure valid in vitro conditions, we developed a cell culture sample chamber allowing us to grow and cultivate cells under proper cell culture conditions while performing in vitro neutron reflectivity measurements. The cell chamber also enabled perfusion with cell medium and hence allowed for contrast variation in situ by sterile exchange of buffer with different H2O-to-D2O ratio. Contrast variation reduces the ambiguity of data modeling for determining the thickness and degree of hydration of the interfacial cleft between the adherent cells and the substrate. Our data suggest a three-layer interfacial organization. The first layer bound to the silicon surface interface is in agreement with a very dense protein film with a thickness of 9 ± 2 nm, followed by a highly hydrated 24 ± 4 nm thick layer, and a several tens of nanometers thick layer attributed to the composite membrane. Hence, the results provide clear evidence of a highly hydrated intermediate region between the composite cell membrane and the substrate, reminiscent of the basal lamina.
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Affiliation(s)
- Philip Böhm
- Fakultät für Physik and Center for NanoScience , Ludwig-Maximilians-Universität , Geschwister-Scholl-Platz 1 , 80539 München , Germany
- Nanosystems Initiative Munich , Schellingstraße 4 , 80799 München , Germany
| | - Alexandros Koutsioubas
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ) , Forschungszentrum Jülich GmbH , Lichtenbergstr. 1 , 85748 Garching , Germany
| | - Jean-François Moulin
- Helmholtz-Zentrum Geesthacht, Zentrum für Material und Küstenforschung , Außenstelle am MLZ in Garching bei München , Lichtenbergstraße 1 , 85748 Garching , Germany
| | - Joachim O Rädler
- Fakultät für Physik and Center for NanoScience , Ludwig-Maximilians-Universität , Geschwister-Scholl-Platz 1 , 80539 München , Germany
- Nanosystems Initiative Munich , Schellingstraße 4 , 80799 München , Germany
| | - Erich Sackmann
- Physikdepartment E22 , Technische Universität München , James-Franck-Str.1 , 85748 Garching , Germany
| | - Bert Nickel
- Fakultät für Physik and Center for NanoScience , Ludwig-Maximilians-Universität , Geschwister-Scholl-Platz 1 , 80539 München , Germany
- Nanosystems Initiative Munich , Schellingstraße 4 , 80799 München , Germany
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18
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Clifton LA, Hall SCL, Mahmoudi N, Knowles TJ, Heinrich F, Lakey JH. Structural Investigations of Protein-Lipid Complexes Using Neutron Scattering. Methods Mol Biol 2019; 2003:201-251. [PMID: 31218621 DOI: 10.1007/978-1-4939-9512-7_11] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Neutron scattering has significant benefits for examining the structure of protein-lipid complexes. Cold (slow) neutrons are nondamaging and predominantly interact with the atomic nucleus, meaning that neutron beams can penetrate deeply into samples, which allows for flexibility in the design of samples studied. Most importantly, there is a strong difference in neutron scattering length (i.e., scattering power) between protium ([Formula: see text], 99.98% natural abundance) and deuterium ([Formula: see text] or D, 0.015%). Through the mixing of H2O and D2O in the samples and in some cases the deuterium labeling of the biomolecules, components within a complex can be hidden or enhanced in the scattering signal. This enables both the overall structure and the relative distribution of components within a complex to be resolved. Lipid-protein complexes are most commonly studied using neutron reflectometry (NR) and small angle neutron scattering (SANS). In this review the methodologies to produce and examine a variety of model biological membrane systems using SANS and NR are detailed. These systems include supported lipid bilayers derived from vesicle dispersions or Langmuir-Blodgett deposition, tethered bilayer systems, membrane protein-lipid complexes and polymer wrapped lipid nanodiscs. The three key stages of any SANS/NR study on model membrane systems-sample preparation, data collection, and analysis-are described together with some background on the techniques themselves.
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Affiliation(s)
- Luke A Clifton
- Rutherford Appleton Laboratory, Science and Technology Facilities Council, Didcot, Oxfordshire, UK.
| | - Stephen C L Hall
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Najet Mahmoudi
- Rutherford Appleton Laboratory, Science and Technology Facilities Council, Didcot, Oxfordshire, UK
| | - Timothy J Knowles
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Frank Heinrich
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA
- National Institute of Standards and Technology Centre for Neutron Research, Gaithersburg, MD, USA
| | - Jeremy H Lakey
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, UK.
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19
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Kurniawan J, Ventrici de Souza JF, Dang AT, Liu GY, Kuhl TL. Preparation and Characterization of Solid-Supported Lipid Bilayers Formed by Langmuir-Blodgett Deposition: A Tutorial. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:15622-15639. [PMID: 30465730 DOI: 10.1021/acs.langmuir.8b03504] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The structure, phase behavior, and properties of cellular membranes are derived from their composition, which includes phospholipids, sphingolipids, sterols, and proteins with various levels of glycosylation. Because of the intricate nature of cellular membranes, a plethora of in vitro studies have been carried out with model membrane systems that capture particular properties such as fluidity, permeability, and protein binding but vastly simplify the membrane composition in order to focus in detail on a specialized property or function. Supported lipid bilayers (SLB) are widely used as archetypes for cellular membranes, and this instructional review primarily focuses on the preparation and characterization of SLB systems formed by Langmuir deposition methods. Typical characterization methods, which take advantage of the planar orientation of SLBs, are illustrated, and references that go into more depth are included. This invited instructional review is written so that nonexperts can quickly gain in-depth knowledge regarding the preparation and characterization of SLBs. In addition, this work goes beyond traditional instructional reviews to provide expert readers with new results that cover a wider range of SLB systems than those previously reported in the literature. The quality of an SLB is frequently not well described, and details such as topological defects can influence the results and conclusions of an individual study. This article quantifies and compares the quality of SLBs fabricated from a variety of gel and fluid compositions, in correlation with preparation techniques and parameters, to generate general rules of thumb to guide the construction of designed SLB systems.
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20
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Niga P, Hansson-Mille PM, Swerin A, Claesson PM, Schoelkopf J, Gane PAC, Dai J, Furó I, Campbell RA, Johnson CM. Propofol adsorption at the air/water interface: a combined vibrational sum frequency spectroscopy, nuclear magnetic resonance and neutron reflectometry study. SOFT MATTER 2018; 15:38-46. [PMID: 30516226 DOI: 10.1039/c8sm01677a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Propofol is an amphiphilic small molecule that strongly influences the function of cell membranes, yet data regarding interfacial properties of propofol remain scarce. Here we consider propofol adsorption at the air/water interface as elucidated by means of vibrational sum frequency spectroscopy (VSFS), neutron reflectometry (NR), and surface tensiometry. VSFS data show that propofol adsorbed at the air/water interface interacts with water strongly in terms of hydrogen bonding and weakly in the proximity of the hydrocarbon parts of the molecule. In the concentration range studied there is almost no change in the orientation adopted at the interface. Data from NR show that propofol forms a dense monolayer with a thickness of 8.4 Å and a limiting area per molecule of 40 Å2, close to the value extracted from surface tensiometry. The possibility that islands or multilayers of propofol form at the air/water interface is therefore excluded as long as the solubility limit is not exceeded. Additionally, measurements of the 1H NMR chemical shifts demonstrate that propofol does not form dimers or multimers in bulk water up to the solubility limit.
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Affiliation(s)
- Petru Niga
- RISE Research Institutes of Sweden - Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm, Sweden.
| | - Petra M Hansson-Mille
- RISE Research Institutes of Sweden - Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm, Sweden.
| | - Agne Swerin
- RISE Research Institutes of Sweden - Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm, Sweden. and KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden.
| | - Per M Claesson
- RISE Research Institutes of Sweden - Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm, Sweden. and KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden.
| | | | - Patrick A C Gane
- Omya International AG, Baslerstrasse 42, CH-4665 Oftringen, Switzerland and Aalto University, School of Chemical Technology, Department of Bioproducts and Biosystems, FI-00076 Aalto, Helsinki, Finland
| | - Jing Dai
- KTH Royal Institute of Technology, Department of Chemistry, Division of Applied Physical Chemistry, SE-100 44 Stockholm, Sweden
| | - István Furó
- KTH Royal Institute of Technology, Department of Chemistry, Division of Applied Physical Chemistry, SE-100 44 Stockholm, Sweden
| | - Richard A Campbell
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS20156, 38042 Grenoble Cedex 9, France and Division of Pharmacy and Optometry, University of Manchester, Manchester M13 9PT, UK
| | - C Magnus Johnson
- KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden.
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21
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Campbell RA, Saaka Y, Shao Y, Gerelli Y, Cubitt R, Nazaruk E, Matyszewska D, Lawrence MJ. Structure of surfactant and phospholipid monolayers at the air/water interface modeled from neutron reflectivity data. J Colloid Interface Sci 2018; 531:98-108. [DOI: 10.1016/j.jcis.2018.07.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/06/2018] [Accepted: 07/06/2018] [Indexed: 10/28/2022]
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22
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Florek OB, Clifton LA, Wilde M, Arnold T, Green RJ, Frazier RA. Lipid composition in fungal membrane models: effect of lipid fluidity. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2018; 74:1233-1244. [PMID: 30605137 DOI: 10.1107/s2059798318009440] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 07/01/2018] [Indexed: 12/25/2022]
Abstract
The creation of effective fungal membrane models for neutron and X-ray reflectometry experiments is a key step in the development of new antifungal pharmaceuticals and agrochemicals to allow in vitro investigation of their mode of interaction with target cells. The structure of the obtained models depends on the properties of the lipids used and the final composition of the leaflets, and can be subject to the spontaneous translocation of phospholipids across the bilayer. The effect of phospholipid acyl-chain unsaturation and the presence of steroids in the membrane on the bilayer asymmetry were examined by means of neutron reflectometry. The measurements showed that membrane stability was higher if a zwitterionic, saturated acyl-chain phospholipid is present as the inner leaflet. Furthermore, membrane asymmetry was higher in the case of fully saturated lipid systems. As a result, membrane models consisting of fully saturated acyl chains within the inner leaflet are recommended as the starting point for subsequent studies of antifungal interactions owing to the simplicity of the models and their relative stability, thus allowing better control over the exact lipid composition facing the tested antifungal.
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Affiliation(s)
- Olga B Florek
- Department of Food and Nutritional Sciences, University of Reading, PO Box 226, Whiteknights, Reading RG6 6AP, England
| | - Luke A Clifton
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX, England
| | - Marleen Wilde
- Reading School of Pharmacy, University of Reading, PO Box 226, Whiteknights, Reading RG6 6AP, England
| | - Thomas Arnold
- I07, Diamond Light Source, Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, England
| | - Rebecca J Green
- Reading School of Pharmacy, University of Reading, PO Box 226, Whiteknights, Reading RG6 6AP, England
| | - Richard A Frazier
- Department of Food and Nutritional Sciences, University of Reading, PO Box 226, Whiteknights, Reading RG6 6AP, England
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23
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Fragneto G, Delhom R, Joly L, Scoppola E. Neutrons and model membranes: Moving towards complexity. Curr Opin Colloid Interface Sci 2018. [DOI: 10.1016/j.cocis.2018.10.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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24
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Poursoroush A, Sperotto MM, Laradji M. Phase behavior of supported lipid bilayers: A systematic study by coarse-grained molecular dynamics simulations. J Chem Phys 2018; 146:154902. [PMID: 28433014 DOI: 10.1063/1.4981008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Solid-supported lipid bilayers are utilized by experimental scientists as models for biological membranes because of their stability. However, compared to free standing bilayers, their close proximity to the substrate may affect their phase behavior. As this is still poorly understood, and few computational studies have been performed on such systems thus far, here we present the results from a systematic study based on molecular dynamics simulations of an implicit-solvent model for solid-supported lipid bilayers with varying lipid-substrate interactions. The attractive interaction between the substrate and the lipid head groups that are closest to the substrate leads to an increased translocation of the lipids from the distal to the proximal bilayer-leaflet. This thereby leads to a transbilayer imbalance of the lipid density, with the lipid density of the proximal leaflet higher than that of the distal leaflet. Consequently, the order parameter of the proximal leaflet is found to be higher than that of the distal leaflet, the higher the strength of lipid interaction is, the stronger the effect. The proximal leaflet exhibits gel and fluid phases with an abrupt melting transition between the two phases. In contrast, below the melting temperature of the proximal leaflet, the distal leaflet is inhomogeneous with coexisting gel and fluid domains. The size of the fluid domains increases with increasing the strength of the lipid interaction. At low temperatures, the inhomogeneity of the distal leaflet is due to its reduced lipid density.
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Affiliation(s)
- Asma Poursoroush
- Department of Physics and Materials Science, The University of Memphis, Memphis, Tennessee 38152, USA
| | - Maria Maddalena Sperotto
- DTU Bioinformatics, Department of Bio and Health Informatics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Mohamed Laradji
- Department of Physics and Materials Science, The University of Memphis, Memphis, Tennessee 38152, USA
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25
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Michel JP, Wang YX, Kiesel I, Gerelli Y, Rosilio V. Disruption of Asymmetric Lipid Bilayer Models Mimicking the Outer Membrane of Gram-Negative Bacteria by an Active Plasticin. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:11028-11039. [PMID: 28921990 DOI: 10.1021/acs.langmuir.7b02864] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The outer membrane (OM) of Gram-negative bacteria is a complex and asymmetric bilayer that antimicrobial peptides must disrupt in order to provoke the cell lysis. The inner and external leaflets of the OM are mainly composed of phospholipids (PL), and lipopolysaccharide (LPS), respectively. Supported lipid bilayers are interesting model systems to mimic the lipid asymmetric scaffold of the OM and determine the quantitative and mechanistic effect of antimicrobial agents, using complementary physicochemical techniques. We report the formation of asymmetric PL/LPS bilayers using the Langmuir-Blodgett/Langmuir-Schaefer technique on two different surfaces (sapphire and mica) with synthetic phospholipids constituting the inner leaflet and bacteria-extracted mutant LPS making up the outer one. The combination of neutron reflectometry and atomic force microscopy techniques allowed the examination of the asymmetric scaffold structure along the normal to the interface and its surface morphology in buffer conditions. Our results allow discrimination of two structurally related peptides, one neutral and inactive, and the other cationic and active. The active cationic plasticin PTCDA1-KF disrupts the asymmetric OM at relevant concentrations through a carpeting scenario characterized by a dramatic removal of lipid molecules from the surface.
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Affiliation(s)
- J P Michel
- Institut Galien Paris Sud, Univ Paris Sud, Université Paris-Saclay, 5 rue Jean-Baptiste Clément, F-92296 Châtenay-Malabry, France
- CNRS, UMR 8612, F-92296 Châtenay-Malabry, France
| | - Y X Wang
- Institut Galien Paris Sud, Univ Paris Sud, Université Paris-Saclay, 5 rue Jean-Baptiste Clément, F-92296 Châtenay-Malabry, France
- CNRS, UMR 8612, F-92296 Châtenay-Malabry, France
| | - I Kiesel
- Institut Laue-Langevin , 71 avenue des Martyrs, 38000, Grenoble, France
| | - Y Gerelli
- Institut Laue-Langevin , 71 avenue des Martyrs, 38000, Grenoble, France
| | - V Rosilio
- Institut Galien Paris Sud, Univ Paris Sud, Université Paris-Saclay, 5 rue Jean-Baptiste Clément, F-92296 Châtenay-Malabry, France
- CNRS, UMR 8612, F-92296 Châtenay-Malabry, France
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26
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Rondelli V, Brocca P, Tranquilli N, Fragneto G, Del Favero E, Cantù L. Building a biomimetic membrane for neutron reflectivity investigation: Complexity, asymmetry and contrast. Biophys Chem 2017; 229:135-141. [PMID: 28499578 DOI: 10.1016/j.bpc.2017.04.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 11/25/2022]
Abstract
The preparation and investigation of model membranes is deserving growing interest both for the physics of complex systems, and for biology. The need of simplified models should preserve mimicking the qualifying characteristics of biological membranes, and keep non-invasive and detailed description. As a main feature, biological membranes are non-homogeneous in the disposition of components, both in the lateral and in the transverse direction. We prepared asymmetric supported membranes containing GM1 ganglioside in biomimetic proportion according to different protocols. Then, we studied their internal structure by neutron reflectometry, providing few-Angstrom sensitivity in the cross direction meanwhile avoiding radiation damage. This technique can also be profitably applied to study interactions at the membrane surface. The best protocol has proven to be the Langmuir-Blodgett/Langmuir-Schaefer depositions. Notably, also the simpler and most accessible protocol of vesicle fusion was found to be suitable for straightforward and good quality deposition of compositionally asymmetric membranes.
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Affiliation(s)
- Valeria Rondelli
- Università degli Studi di Milano, BIOMETRA, Via F.lli Cervi, 93, 20090 Segrate, Italy.
| | - Paola Brocca
- Università degli Studi di Milano, BIOMETRA, Via F.lli Cervi, 93, 20090 Segrate, Italy
| | - Nicola Tranquilli
- Università degli Studi di Milano, BIOMETRA, Via F.lli Cervi, 93, 20090 Segrate, Italy
| | - Giovanna Fragneto
- Institut Laue-Langevin, 71 Avenue des Martyrs, BP 156, 38000 Grenoble Cedex, France
| | - Elena Del Favero
- Università degli Studi di Milano, BIOMETRA, Via F.lli Cervi, 93, 20090 Segrate, Italy
| | - Laura Cantù
- Università degli Studi di Milano, BIOMETRA, Via F.lli Cervi, 93, 20090 Segrate, Italy
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Wah B, Breidigan JM, Adams J, Horbal P, Garg S, Porcar L, Perez-Salas U. Reconciling Differences between Lipid Transfer in Free-Standing and Solid Supported Membranes: A Time-Resolved Small-Angle Neutron Scattering Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:3384-3394. [PMID: 28300412 DOI: 10.1021/acs.langmuir.6b04013] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Maintaining compositional lipid gradients across membranes in animal cells is essential to biological function, but what is the energetic cost to maintain these differences? It has long been recognized that studying the passive movement of lipids in membranes can provide insight into this toll. Confusingly the reported values of inter- and, particularly, intra-lipid transport rates of lipids in membranes show significant differences. To overcome this difficulty, biases introduced by experimental approaches have to be identified. The present study addresses the difference in the reported intramembrane transport rates of dimyristoylphosphatidylcholine (DMPC) on flat solid supports (fast flipping) and in curved free-standing membranes (slow flipping). Two possible scenarios are potentially at play: one is the difference in curvature of the membranes studied and the other the presence (or not) of the support. Using DMPC vesicles and DMPC supported membranes on silica nanoparticles of different radii, we found that an increase in curvature (from a diameter of 30 nm to a diameter of 100 nm) does not change the rates significantly, differing only by factors of order ∼1. Additionally, we found that the exchange rates of DMPC in supported membranes are similar to the ones in vesicles. And as previously reported, we found that the activation energies for exchange on free-standing and supported membranes are similar (84 and 78 kJ/mol, respectively). However, DMPC's flip-flop rates increase significantly when in a supported membrane, surpassing the exchange rates and no longer limiting the exchange process. Although the presence of holes or cracks in supported membranes explains the occurrence of fast lipid flip-flop in many studies, in defect-free supported membranes we find that fast flip-flop is driven by the surface's induced disorder of the bilayer's acyl chain packing as evidenced from their broad melting temperature behavior.
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Affiliation(s)
- Benny Wah
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
| | - Jeffrey M Breidigan
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
| | - Joseph Adams
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
| | - Piotr Horbal
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
| | - Sumit Garg
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
- Materials Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States
| | - Lionel Porcar
- Large Scale Structure Group, Institut Laue-Langevin , Grenoble F-38042, France
- Department of Chemical Engineering, Colburn Laboratory, University of Delaware , Newark, Delaware 19716, United States
| | - Ursula Perez-Salas
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
- Materials Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States
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28
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Hayden SC, Junghans A, Majewski J, Firestone MA. Reversible Lifting of Surface Supported Lipid Bilayers with a Membrane-Spanning Nonionic Triblock Copolymer. Biomacromolecules 2017; 18:1097-1107. [DOI: 10.1021/acs.biomac.6b01461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Steven C. Hayden
- Materials Physics & Applications, Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Mail Stop K771, Los Alamos, New Mexico 87545, United States
| | - Ann Junghans
- Lujan
Neutron Scattering Center, Los Alamos Neutron Science Center (LANSCE), Los Alamos National Laboratory, Mail Stop H805, Los Alamos, New Mexico 87545, United States
- Materials Science & Engineering (MST-7), Los Alamos National Laboratory, Mail Stop H805, Los Alamos, New Mexico 87545, United States
| | - Jaroslaw Majewski
- Materials Physics & Applications, Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Mail Stop K771, Los Alamos, New Mexico 87545, United States
- Lujan
Neutron Scattering Center, Los Alamos Neutron Science Center (LANSCE), Los Alamos National Laboratory, Mail Stop H805, Los Alamos, New Mexico 87545, United States
- Department
of Chemical Engineering, University of California Davis, Davis, California 95616, United States
| | - Millicent A. Firestone
- Materials Physics & Applications, Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Mail Stop K771, Los Alamos, New Mexico 87545, United States
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29
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Biological Structures. NEUTRON SCATTERING - APPLICATIONS IN BIOLOGY, CHEMISTRY, AND MATERIALS SCIENCE 2017. [DOI: 10.1016/b978-0-12-805324-9.00001-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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30
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Clifton LA, Ciesielski F, Skoda MWA, Paracini N, Holt SA, Lakey JH. The Effect of Lipopolysaccharide Core Oligosaccharide Size on the Electrostatic Binding of Antimicrobial Proteins to Models of the Gram Negative Bacterial Outer Membrane. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:3485-94. [PMID: 27003358 PMCID: PMC4854487 DOI: 10.1021/acs.langmuir.6b00240] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 02/28/2016] [Indexed: 05/23/2023]
Abstract
Understanding the electrostatic interactions between bacterial membranes and exogenous proteins is crucial to designing effective antimicrobial agents against Gram-negative bacteria. Here we study, using neutron reflecometry under multiple isotopic contrast conditions, the role of the uncharged sugar groups in the outer core region of lipopolysaccharide (LPS) in protecting the phosphate-rich inner core region from electrostatic interactions with antimicrobial proteins. Models of the asymmetric Gram negative outer membrane on silicon were prepared with phopshatidylcholine (PC) in the inner leaflet (closest to the silicon), whereas rough LPS was used to form the outer leaflet (facing the bulk solution). We show how salt concentration can be used to reversibly alter the binding affinity of a protein antibiotic colicin N (ColN) to the anionic LPS confirming that the interaction is electrostatic in nature. By examining the interaction of ColN with two rough LPS types with different-sized core oligosaccharide regions we demonstrate the role of uncharged sugars in blocking short-range electrostatic interactions between the cationic antibiotics and the vulnerable anionic phosphate groups.
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Affiliation(s)
- Luke A Clifton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory , Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 OQX, United Kingdom
| | - Filip Ciesielski
- Department of Plant Sciences, University of Oxford , Oxford, OX1 3RB, United Kingdom
| | - Maximilian W A Skoda
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory , Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 OQX, United Kingdom
| | - Nicolò Paracini
- Institute for Cell and Molecular Biosciences, Newcastle University , Framlington Place, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Stephen A Holt
- Bragg Institute, Australian Nuclear Science and Technology Organisation , Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Jeremy H Lakey
- Institute for Cell and Molecular Biosciences, Newcastle University , Framlington Place, Newcastle upon Tyne, NE2 4HH, United Kingdom
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31
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Abstract
Auroreis a free software application based on MATLAB scripts designed for the graphical analysis, inspection and simulation of neutron reflectivity data. Its architecture, combined with graphics and other advantages of the MATLAB environment, should allow continued development of this software and inclusion of new features and analysis methods. The development of the software was driven by the necessity for a non-commercial open-source application for the analysis of neutron reflectivity data.Auroreprovides a robust and reliable method for evaluation of parameter uncertainty, a feature almost absent in similar software applications. In the present paper the main functionalities of the software are presented, together with a comprehensive description of the modeling approaches available at the moment. The code is released under a Creative Commons Attribution Non-Commercial License V2.0. The software application can be downloaded at http://aurorenr.sourceforge.net/.
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32
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Belička M, Gerelli Y, Kučerka N, Fragneto G. The component group structure of DPPC bilayers obtained by specular neutron reflectometry. SOFT MATTER 2015; 11:6275-6283. [PMID: 26160133 DOI: 10.1039/c5sm00274e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Specular neutron reflectometry was measured on a floating bilayer system consisting of 1,2-dipalmitoyl-d62-sn-glycero-3-phosphocholine deposited over a 1,2-dibehenoyl-sn-glycero-3-phosphocholine bilayer at 25 and 55 °C. The internal structure of lipid bilayers was described by a one-dimensional neutron scattering length density profile model, originally developed for the evaluation of small-angle scattering data. The reflectivity data from the supported bilayer were evaluated separately and used further as constraints in modeling the floating bilayer reflectivity curves. The model reflectivity curves successfully describe the experimental reflectivities of the supported bilayer in the gel phase and the floating bilayer system in the liquid-crystalline phase. The results yield an internal structure of a deposited bilayer and a floating bilayer on the level of component groups of lipid molecules. The obtained structure of the floating d62-diC16:0PC bilayer displays high resemblance of the bilayer structure in the form of unilamellar vesicles. At the same time, however, the results show differences in comparison to unilamellar vesicle bilayers, most likely due to the undulations of supported bilayers.
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Affiliation(s)
- Michal Belička
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University, Odbojárov 10, SK-832 32 Bratislava, Slovakia.
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33
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Clifton LA, Skoda MA, Le Brun A, Ciesielski F, Kuzmenko I, Holt SA, Lakey JH. Effect of divalent cation removal on the structure of gram-negative bacterial outer membrane models. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 31:404-12. [PMID: 25489959 PMCID: PMC4295546 DOI: 10.1021/la504407v] [Citation(s) in RCA: 224] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 12/09/2014] [Indexed: 05/18/2023]
Abstract
The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS are polyanionic molecules, with numerous phosphate groups present in the lipid A and core oligosaccharide regions. The repulsive forces due to accumulation of the negative charges are screened and bridged by the divalent cations (Mg(2+) and Ca(2+)) that are known to be crucial for the integrity of the bacterial OM. Indeed, chelation of divalent cations is a well-established method to permeabilize Gram-negative bacteria such as Escherichia coli. Here, we use X-ray and neutron reflectivity (XRR and NR, respectively) techniques to examine the role of calcium ions in the stability of a model GNB-OM. Using XRR we show that Ca(2+) binds to the core region of the rough mutant LPS (RaLPS) films, producing more ordered structures in comparison to divalent cation free monolayers. Using recently developed solid-supported models of the GNB-OM, we study the effect of calcium removal on the asymmetry of DPPC:RaLPS bilayers. We show that without the charge screening effect of divalent cations, the LPS is forced to overcome the thermodynamically unfavorable energy barrier and flip across the hydrophobic bilayer to minimize the repulsive electrostatic forces, resulting in about 20% mixing of LPS and DPPC between the inner and outer bilayer leaflets. These results reveal for the first time the molecular details behind the well-known mechanism of outer membrane stabilization by divalent cations. This confirms the relevance of the asymmetric models for future studies of outer membrane stability and antibiotic penetration.
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Affiliation(s)
- Luke A. Clifton
- ISIS
Pulsed Neutron and Muon Source, Science and Technology Facilities
Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 OQX, United Kingdom
| | - Maximilian
W. A. Skoda
- ISIS
Pulsed Neutron and Muon Source, Science and Technology Facilities
Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 OQX, United Kingdom
| | - Anton
P. Le Brun
- Bragg
Institute, Australian Nuclear Science and
Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Filip Ciesielski
- ISIS
Pulsed Neutron and Muon Source, Science and Technology Facilities
Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 OQX, United Kingdom
| | - Ivan Kuzmenko
- Advanced
Photon Source , Argonne National Laboratories, Argonne, Illinois 60439, United States
| | - Stephen A. Holt
- Bragg
Institute, Australian Nuclear Science and
Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Jeremy H. Lakey
- Institute
for Cell and Molecular Biosciences, Newcastle
University, Framlington
Place, Newcastle upon Tyne NE2 4HH, United Kingdom
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34
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Pomorski TG, Nylander T, Cárdenas M. Model cell membranes: discerning lipid and protein contributions in shaping the cell. Adv Colloid Interface Sci 2014; 205:207-20. [PMID: 24268587 DOI: 10.1016/j.cis.2013.10.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 10/24/2013] [Accepted: 10/24/2013] [Indexed: 01/01/2023]
Abstract
The high complexity of biological membranes has motivated the development and application of a wide range of model membrane systems to study biochemical and biophysical aspects of membranes in situ under well defined conditions. The aim is to provide fundamental understanding of processes controlled by membrane structure, permeability and curvature as well as membrane proteins by using a wide range of biochemical, biophysical and microscopic techniques. This review gives an overview of some currently used model biomembrane systems. We will also discuss some key membrane protein properties that are relevant for protein-membrane interactions in terms of protein structure and how it is affected by membrane composition, phase behavior and curvature.
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Affiliation(s)
- Thomas Günther Pomorski
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark
| | - Tommy Nylander
- Department of Chemistry, Division of Physical Chemistry, Lund University, Gettingevägen 60, SE-22100 Lund, Sweden
| | - Marité Cárdenas
- Department of Chemistry/Nano-Science Center, University of Copenhagen, DK-2100 Copenhagen, Denmark.
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35
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Clifton LA, Skoda MWA, Daulton EL, Hughes AV, Le Brun AP, Lakey JH, Holt SA. Asymmetric phospholipid: lipopolysaccharide bilayers; a Gram-negative bacterial outer membrane mimic. J R Soc Interface 2013; 10:20130810. [PMID: 24132206 PMCID: PMC3808558 DOI: 10.1098/rsif.2013.0810] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 09/25/2013] [Indexed: 01/02/2023] Open
Abstract
The Gram-negative bacterial outer membrane (OM) is a complex and highly asymmetric biological barrier but the small size of bacteria has hindered advances in in vivo examination of membrane dynamics. Thus, model OMs, amenable to physical study, are important sources of data. Here, we present data from asymmetric bilayers which emulate the OM and are formed by a simple two-step approach. The bilayers were deposited on an SiO2 surface by Langmuir-Blodgett deposition of phosphatidylcholine as the inner leaflet and, via Langmuir-Schaefer deposition, an outer leaflet of either Lipid A or Escherichia coli rough lipopolysaccharides (LPS). The membranes were examined using neutron reflectometry (NR) to examine the coverage and mixing of lipids between the bilayer leaflets. NR data showed that in all cases, the initial deposition asymmetry was mostly maintained for more than 16 h. This stability enabled the sizes of the headgroups and bilayer roughness of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and Lipid A, Rc-LPS and Ra-LPS to be clearly resolved. The results show that rough LPS can be manipulated like phospholipids and used to fabricate advanced asymmetric bacterial membrane models using well-known bilayer deposition techniques. Such models will enable OM dynamics and interactions to be studied under in vivo-like conditions.
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Affiliation(s)
- Luke A. Clifton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, Oxfordshire OX11 OQX, UK
| | - Maximilian W. A. Skoda
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, Oxfordshire OX11 OQX, UK
| | - Emma L. Daulton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, Oxfordshire OX11 OQX, UK
- Department of Chemistry, University of Bath, Bath BA2 7AY, UK
| | - Arwel V. Hughes
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, Oxfordshire OX11 OQX, UK
| | - Anton P. Le Brun
- Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Jeremy H. Lakey
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Stephen A. Holt
- Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
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36
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Gerelli Y, Porcar L, Lombardi L, Fragneto G. Lipid exchange and flip-flop in solid supported bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:12762-9. [PMID: 24044771 DOI: 10.1021/la402708u] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Inter- and intrabilayer transfer of phospholipid molecules was investigated by neutron reflectometry. The structure of solid supported lipid bilayers exposed to a solution of isotopically labeled vesicles was monitored as a function of temperature, time, and vesicle concentration. Lipid interbilayer exchange was shown to be the time limiting process, while lipid intrabilayer movement, the so-called flip-flop, was too fast to be visualized within the experimental acquisition time. The exchange process was characterized by an Arrhenius-like behavior and the activation energy of the process was concentration-independent. The results are discussed and compared extensively with the literature available on the topic.
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Affiliation(s)
- Yuri Gerelli
- Institut Laue-Langevin , 6, rue Jules Horowitz, 38042, Grenoble CEDEX 9, France
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37
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Rondelli V, Del Favero E, Motta S, Cantù L, Fragneto G, Brocca P. Neutrons for rafts, rafts for neutrons. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2013; 36:73. [PMID: 23852579 DOI: 10.1140/epje/i2013-13073-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 03/08/2013] [Accepted: 03/11/2013] [Indexed: 06/02/2023]
Abstract
The determination of the structure of membrane rafts is a challenging issue in biology. The selection of membrane components both in the longitudinal and transverse directions plays a major role as it determines the creation of stable or tunable platforms that host interactions with components of the outer environment. We focus here on the possibility to apply neutron scattering to the study of raft mimics. With this aim, we realized two extreme experimental models for the same complex membrane system (phospholipid : cholesterol : ganglioside GM1), involving two of the characteristic components of glycolipid-enriched rafts. One consists of a thick stack of tightly packed membranes, mixed and symmetric in composition, deposited on a silicon wafer and analyzed by neutron diffraction. The other consists of a free floating individual membrane, mixed and asymmetric in composition in the two layers, studied by neutron reflection. We present here results on the ganglioside-cholesterol coupling. Ganglioside GM1 is found to force the redistribution of cholesterol between the two layers of the model membranes. This causes cholesterol exclusion from compositionally symmetric ganglioside-containing membranes, or, alternatively, asymmetric cholesterol enrichment in raft-mimics, where gangliosides reside into the opposite layer.
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Affiliation(s)
- V Rondelli
- Department of Medical Biotechnologies and Traslational Medicine, University of Milan, Segrate, Italy
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38
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Schneck E, Jentschel M, Gege C, Tanaka M, Demé B. Grazing-incidence neutron-induced fluorescence probes density profiles of labeled molecules at solid/liquid interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:4084-4091. [PMID: 23461763 DOI: 10.1021/la400162y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report on the use of characteristic prompt γ-fluorescence after neutron capture induced by an evanescent neutron wave to probe densities and depth profiles of labeled molecules at solid/liquid interfaces. In contrast to classical scattering techniques and X-ray fluorescence, this method of "grazing-incidence neutron-induced fluorescence" combines direct chemical specificity, provided by the label, with sensitivity to the interface, inherent to the evanescent wave. We demonstrate that the formation of a supported lipid membrane can be quantitatively monitored from the characteristic fluorescence of (157)Gd(3+) ions bound to the headgroup of chelator lipids. Moreover, we were able to localize the (157)Gd(3+) ions along the surface normal with nanometer precision. This first proof of principle with a well-defined model system suggests that the method has a great potential for biology and soft matter studies where spatial resolution and chemical sensitivity are required.
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Affiliation(s)
- Emanuel Schneck
- Physical Chemistry of Biosystems, Institute of Physical Chemistry, University of Heidelberg, Heidelberg, Germany.
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