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Rimoli CV, de Oliveira Pedro R, Miranda PB. Interaction mechanism of chitosan oligomers in pure water with cell membrane models studied by SFG vibrational spectroscopy. Colloids Surf B Biointerfaces 2022; 219:112782. [PMID: 36063719 DOI: 10.1016/j.colsurfb.2022.112782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/10/2022] [Accepted: 08/17/2022] [Indexed: 11/20/2022]
Abstract
Chitosan is a versatile and biocompatible cationic antimicrobial polymer obtained from sustainable sources that is effective against a wide range of microorganisms. Although it is soluble only at low pH, chitosan oligomers (ChitO) are soluble in pure water and thus more appropriate for antibacterial applications. Although there is a vast literature on chitosan's antimicrobial activity, the molecular details of its interaction with biomembranes remain unclear. Here we investigate these molecular interactions by resorting to phospholipid Langmuir films (zwitterionic DPPC and anionic DPPG) as simplified membrane models (for mammalian and bacterial membranes, respectively), and using SFG vibrational spectroscopy to probe lipid tail conformation, headgroup dynamics and interfacial water orientation. For comparison, we also investigate the interactions of another simple cationic antimicrobial polyelectrolyte, poly(allylamine) hydrochloride - PAH. By forming the lipid films over the polyelectrolyte solutions, we found that both have only a very small interaction with DPPC, but PAH adsorption is able to invert the interfacial water orientation (membrane potential). This might explain why ChitO is compatible with mammalian cells, while PAH is toxic. In contrast, their interaction with DPPG films is much stronger, even more so for ChitO, with both insertion within the lipid film and interaction with the oppositely charged headgroups. Again, PAH adsorption inverts the membrane potential, while ChitO does not. Finally, ChitO interaction with DPPG is weaker if the antimicrobial is injected underneath a pre-assembled Langmuir film, and its interaction mode depends on the time interval between end of film compression and ChitO injection. These differences between ChitO and PAH effects on the model membranes highlight the importance of molecular structure and intermolecular interactions for their bioactivity, and therefore this study may provide insights for the rational design of more effective antimicrobial molecules.
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Affiliation(s)
- Caio Vaz Rimoli
- Sao Carlos Physics Institute, University of Sao Paulo, CP 369, Sao Carlos CEP 13560-970, SP, Brazil; Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, College de France, 24 Rue Lhomond, F-75005 Paris, France
| | - Rafael de Oliveira Pedro
- Sao Carlos Physics Institute, University of Sao Paulo, CP 369, Sao Carlos CEP 13560-970, SP, Brazil; Department of exact and earth sciences, Minas Gerais State University (UEMG), Ituiutaba CEP 38302-192, MG, Brazil
| | - Paulo B Miranda
- Sao Carlos Physics Institute, University of Sao Paulo, CP 369, Sao Carlos CEP 13560-970, SP, Brazil.
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Lechner BD, Smith P, McGill B, Marshall S, Trick JL, Chumakov AP, Winlove CP, Konovalov OV, Lorenz CD, Petrov PG. The Effects of Cholesterol Oxidation on Erythrocyte Plasma Membranes: A Monolayer Study. MEMBRANES 2022; 12:828. [PMID: 36135847 PMCID: PMC9506283 DOI: 10.3390/membranes12090828] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 06/16/2023]
Abstract
Cholesterol plays a key role in the molecular and mesoscopic organisation of lipid membranes and it is expected that changes in its molecular structure (e.g., through environmental factors such as oxidative stress) may affect adversely membrane properties and function. In this study, we present evidence that oxidation of cholesterol has significant effects on the mechanical properties, molecular and mesoscopic organisation and lipid-sterol interactions in condensed monolayers composed of the main species found in the inner leaflet of the erythrocyte membrane. Using a combination of experimental methods (static area compressibility, surface dilatational rheology, fluorescence microscopy, and surface sensitive X-ray techniques) and atomistic molecular dynamics simulations, we show that oxidation of cholesterol to 7-ketocholesterol leads to stiffening of the monolayer (under both static and dynamic conditions), significant changes in the monolayer microdomain organisation, disruption in the van der Waals, electrostatic and hydrophobic interactions between the sterol and the other lipid species, and the lipid membrane hydration. Surface sensitive X-ray techniques reveal that, whilst the molecular packing mode is not significantly affected by cholesterol oxidation in these condensed phases, there are subtle changes in membrane thickness and a significant decrease in the coherence length in monolayers containing 7-ketocholesterol.
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Affiliation(s)
- Bob-Dan Lechner
- Department of of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Paul Smith
- Department of Physics, King’s College London, The Strand, London WC2R 2LS, UK
| | - Beth McGill
- Department of of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Skye Marshall
- Department of of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Jemma L. Trick
- Department of Physics, King’s College London, The Strand, London WC2R 2LS, UK
| | - Andrei P. Chumakov
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Charles Peter Winlove
- Department of of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Oleg V. Konovalov
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Christian D. Lorenz
- Department of Physics, King’s College London, The Strand, London WC2R 2LS, UK
| | - Peter G. Petrov
- Department of of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
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Malajczuk CJ, Stachura SS, Hendry JO, Mancera RL. Redefining the Molecular Interplay between Dimethyl Sulfoxide, Lipid Bilayers, and Dehydration. J Phys Chem B 2022; 126:2513-2529. [PMID: 35344357 DOI: 10.1021/acs.jpcb.2c00353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The potentially damaging action of dimethyl sulfoxide (DMSO) on phospholipid bilayers remains a matter of controversy. We have conducted a series of long-scale molecular dynamics simulations of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayers at various levels of hydration in the presence of variable quantities of DMSO. These simulations provide evidence for a non-destructive dehydrating mechanism of action for DMSO on DOPC bilayers across a wide concentration range and levels of hydration. Specifically, under full- and low-hydration conditions, the bilayer underwent a minor lateral contraction, coinciding with surface dehydration in the presence of dilute DMSO solutions (XDMSO < 0.3). At higher DMSO concentrations, this bilayer structure was retained despite a progressive deterioration of the hydration structure at the interface. A similar convergence of bilayer structural properties was observed under dehydration conditions for 0.3 < XDMSO < 0.7. Destabilization occurred for dehydrated bilayers in the presence of XDMSO ≥ 0.7, suggesting the existence of a DMSO concentration and/or dehydration threshold. However, such DMSO concentrations far exceed those established as toxic to other cellular components. Our findings represent a computational model for DMSO-DOPC interactions that is consistent with a range of experimental characterizations, offering new molecular insights into the cryoprotective mechanisms of action of DMSO.
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Affiliation(s)
- Chris J Malajczuk
- Curtin Medical School, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia
| | - Sławomir S Stachura
- Curtin Medical School, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia
| | - James O Hendry
- Curtin Medical School, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia
| | - Ricardo L Mancera
- Curtin Medical School, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, Western Australia 6845, Australia
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Kundu S, Malik S, Ghosh M, Nandi S, Pyne A, Debnath A, Sarkar N. A Comparative Study on DMSO-Induced Modulation of the Structural and Dynamical Properties of Model Bilayer Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:2065-2078. [PMID: 33529530 DOI: 10.1021/acs.langmuir.0c03037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Modulating the structures and properties of biomembranes via permeation of small amphiphilic molecules is immensely important, having diverse applications in cell biology, biotechnology, and pharmaceuticals, because their physiochemical and biological interactions lead to new pathways for transdermal drug delivery and administration. In this work, we have elucidated the role of dimethyl sulfoxide (DMSO), broadly used as a penetration-enhancing agent and cryoprotective agent on model lipid membranes, using a combination of fluorescence microscopy and time-resolved fluorescence spectroscopy. Spatially resolved fluorescence lifetime imaging microscopy (FLIM) has been employed to unravel how the fluidity of the DMSO-induced bilayer regulates the structural alteration of the vesicles. Moreover, we have also shown that the dehydration effect of DMSO leads to weakening of the hydrogen bond between lipid headgroups and water molecules and results in faster solvation dynamics as demonstrated by femtosecond time-resolved fluorescence spectroscopy. It has been gleaned that the water dynamics becomes faster because bilayer rigidity decreases in the presence of DMSO, which is also supported by time-resolved rotational anisotropy measurements. The enhanced diffusivity and increased membrane fluidity in the presence of DMSO are further ratified at the single-molecule level through fluorescence correlation spectroscopy (FCS) measurements. Our results indicate that while the presence of DMSO significantly affects the 1,2-dimyristoyl-rac-glycero-3-phosphocholine (DMPC) and 1,2-dipalmitoyl-rac-glycero-3-phosphatidylcholine (DPPC) bilayers, it has a weak effect on 1,2-dimyristoyl-sn-glycero-3-phospho-rac-glycerol (DMPG) vesicles, which might explain the preferential interaction of DMSO with the positively charged choline group present in DMPC and DPPC vesicles. The experimental findings have also been further verified with molecular dynamics simulation studies. Moreover, it has been observed that DMSO is likely to have a differential effect on heterogeneous bilayer membranes depending on the structure and composition of their headgroups. Our results illuminate the importance of probing the lipid structure and composition of cellular membranes in determining the effects of cryoprotective agents.
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Affiliation(s)
- Sangita Kundu
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| | - Sheeba Malik
- Department of Chemistry, Indian Institute of Technology Jodhpur, Jodhpur 342037, Rajasthan, India
| | - Meghna Ghosh
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| | - Sourav Nandi
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| | - Arghajit Pyne
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
| | - Ananya Debnath
- Department of Chemistry, Indian Institute of Technology Jodhpur, Jodhpur 342037, Rajasthan, India
| | - Nilmoni Sarkar
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India
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Pink DL, Foglia F, Barlow DJ, Lawrence MJ, Lorenz CD. The Impact of Lipid Digestion on the Dynamic and Structural Properties of Micelles. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2004761. [PMID: 33470509 DOI: 10.1002/smll.202004761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/02/2020] [Indexed: 06/12/2023]
Abstract
Self-assembled, lipid-based micelles, such as those formed by the short-chain phosphocholine, dihexanoylphosphatidylcholine (2C6PC), are degraded by the pancreatic enzyme, phospholipase A2 (PLA2). Degradation yields 1-hexanoyl-lysophosphocholine (C6LYSO) and hexanoic acid (C6FA) products. However, little is known about the behavior of these products during and after the degradation of 2C6PC. In this work, a combination of static and time-resolved small angle neutron scattering, as well as all-atom molecular dynamics simulations, is used to characterize the structure of 2C6PC micelles. In doing so a detailed understanding of the substrate and product aggregation behavior before, during and after degradation is gained. Consequently, the formation of mixed micelles containing 2C6PC, C6LYSO and C6FA is shown at every stage of the degradation process, as well as the formation of mixed C6LYSO/C6FA micelles after degradation is complete. The use of atomistic molecular dynamics has allowed us to characterize the structure of 2C6PC, 2C6PC/C6LYSO/C6FA, and C6LYSO/C6FA micelles throughout the degradation process, showing the localization of the different molecular species within the aggregates. In addition, the hydration of the 2C6PC, C6LYSO, and C6FA species both during micellization and as monomers in aqueous solution is documented to reveal the processes driving their micellization.
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Affiliation(s)
- Demi L Pink
- Department of Physics, King's College London, London, WC2R 2LS, UK
| | - Fabrizia Foglia
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - David J Barlow
- Faculty of Life Sciences and Medicine, King's College London, Franklin-Wilkins Building, Stamford Street, London, SE1 9NH, UK
| | - M Jayne Lawrence
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PL, UK
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The Antifungal Mechanism of Amphotericin B Elucidated in Ergosterol and Cholesterol-Containing Membranes Using Neutron Reflectometry. NANOMATERIALS 2020; 10:nano10122439. [PMID: 33291326 PMCID: PMC7762259 DOI: 10.3390/nano10122439] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 12/25/2022]
Abstract
We have characterized and compared the structures of ergosterol- and cholesterol-containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes before and after interaction with the amphiphilic antifungal drug amphotericin B (AmB) using neutron reflection. AmB inserts into both pure POPC and sterol-containing membranes in the lipid chain region and does not significantly perturb the structure of pure POPC membranes. By selective per-deuteration of the lipids/sterols, we show that AmB extracts ergosterol but not cholesterol from the bilayers and inserts to a much higher degree in the cholesterol-containing membranes. Ergosterol extraction by AmB is accompanied by membrane thinning. Our results provide new insights into the mechanism and antifungal effect of AmB in these simple models of fungal and mammalian membranes and help understand the molecular origin of its selectivity and toxic side effects.
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Raju R, Torrent-Burgués J, Bryant G. Interactions of cryoprotective agents with phospholipid membranes - A Langmuir monolayer study. Chem Phys Lipids 2020; 231:104949. [DOI: 10.1016/j.chemphyslip.2020.104949] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 07/02/2020] [Accepted: 07/14/2020] [Indexed: 01/12/2023]
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9
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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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Venkatraman RK, Baiz CR. Ultrafast Dynamics at the Lipid-Water Interface: DMSO Modulates H-Bond Lifetimes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:6502-6511. [PMID: 32423219 DOI: 10.1021/acs.langmuir.0c00870] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Dimethyl sulfoxide (DMSO) is a common cosolvent and cryopreservation agent used to freeze cells and tissues. DMSO alters the H-bond structure of water, but its interactions with biomolecules and, specifically, with biological interfaces remain poorly understood. Here we investigate the effects of DMSO on the H-bond dynamics at the lipid-water interface using a combination of ultrafast two-dimensional infrared (2D IR) spectroscopy and molecular dynamics simulations. Ester carbonyl absorption spectra show that DMSO dehydrates the interface, and simulations show that the area per lipid is decreased. Ultrafast 2D IR spectra measure the time scales of frequency fluctuations at the ester carbonyl positions located precisely between the hydrophobic and hydrophilic regions of the membrane. 2D IR measurements show that low DMSO concentrations (<10 mol %) induce ∼40% faster H-bond dynamics compared with pure water, whereas increased concentrations (>10-20 mol %) once again slow down the dynamics. This slow-fast-slow trend is described in terms of two different solvation regimes. Below 10 mol %, DMSO weakens the interfacial H bond, leading to faster "bulk-like" dynamics, whereas above 10 mol %, water molecules become "relatively immobilized" as the H-bond networks becoming disrupted by the H-bond donor/acceptor imbalance at the interface. These studies are an important step toward characterizing the environments around lipid membranes, which are essential to numerous biological processes.
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Affiliation(s)
- Ravi Kumar Venkatraman
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Carlos R Baiz
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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Gironi B, Lapini A, Ragnoni E, Calvagna C, Paolantoni M, Morresi A, Sassi P. Free volume and dynamics in a lipid bilayer. Phys Chem Chem Phys 2019; 21:23169-23178. [PMID: 31612182 DOI: 10.1039/c9cp03451j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The lateral diffusion of lipids and of small molecules inside a membrane is strictly related to the arrangement of acyl chains and to their mobility. In this study, we use FTIR and time resolved 2D-IR spectroscopic techniques to characterize the structure and dynamics of the hydrophobic region of palmitoyl-oleylphosphatidylcholine/cholesterol vesicles dispersed in water/dimethylsulfoxide solutions. By means of a non-polar probe, hexacarbonyl tungsten, we monitor the distribution of free volumes inside the bilayer and the conformational dynamics of hydrophobic tails in relation to the different compositions of the membrane or the different compositions of the solvent. Despite the important structural changes induced by the presence of DMSO in the solvating medium, the picosecond dynamics of the membrane is preserved under the different conditions.
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Affiliation(s)
- Beatrice Gironi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy.
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Panzuela S, Tieleman DP, Mederos L, Velasco E. Molecular Ordering in Lipid Monolayers: An Atomistic Simulation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13782-13790. [PMID: 31553617 DOI: 10.1021/acs.langmuir.9b02635] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report on atomistic simulations of DPPC lipid monolayers using the CHARMM36 lipid force field (and also the Slipid force field as a control case), combined with a four-point OPC water model. The entire two-phase region where domains of the "liquid-condensed" (LC) phase coexist with domains of the "liquid-expanded" (LE) phase has been explored. The simulations are long enough that the complete phase-transition stage, with two domains coexisting in the monolayer, is reached in all cases. Also, system sizes used are larger than those in previous works. As expected, domains of the minority phase are elongated, emphasizing the importance of anisotropic van der Waals and/or electrostatic dipolar interactions in the monolayer plane. The molecular structure is quantified in terms of distribution functions for the hydrocarbon chains and the PN dipoles. In contrast to previous work, where average distributions are calculated, distributions are here extracted for each of the coexisting phases by first identifying lipid molecules that belong to either LC or LE regions. In the case of the CHARMM36 force field, the three-dimensional distributions show that the average tilt angle of the chains with respect to the normal outward direction is (39.0 ± 0.1)° in the LC phase and (48.1 ± 0.5)° in the LC phase. In the case of the PN dipoles, the distributions indicate a tilt angle of (110.8 ± 0.5)° in the LC phase and (112.5 ± 0.5)° in the LE phase. These results are quantitatively different from those in previous works, which indicated a smaller normal component of the PN dipole. Also, the distributions of the monolayer-projected chains and PN dipoles have been calculated. Chain distributions peak along a particular direction in the LC domains, while they are uniform in the LE phase. Long-range ordering associated with the projected PN dipoles is absent in both phases. These results strongly suggest that LC domains do not exhibit dipolar ordering in the plane of the monolayer, the effect of these components being averaged out at short distances. Therefore, the only relevant component of the molecular dipoles, with regard to both intra- and long-range interdomain interactions, is normal to the monolayer. Also, the local orientation of chain projections is almost constant in LC domains and points in the direction along which domains are elongated, suggesting that the line tension driving the phase transition might be anisotropic with respect to the interfacial domain boundary.
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Affiliation(s)
- S Panzuela
- Departamento de Física Teórica de la Materia Condensada , Universidad Autónoma de Madrid , E-28049 Madrid , Spain
| | - D P Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences , University of Calgary , Calgary , Alberta T2N1N4 , Canada
| | - L Mederos
- Instituto de Ciencia de Materiales de Madrid , Consejo Superior de Investigaciones Científicas , C/Sor Juana Inés de la Cruz, 3 , E-28049 Madrid , Spain
| | - E Velasco
- Departamento de Física Teórica de la Materia Condensada, Instituto de Ciencias de Materiales Nicolás Cabrera, and IFIMAC , Universidad Autónoma de Madrid , E-28049 Madrid , Spain
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Gironi B, Oliva R, Petraccone L, Paolantoni M, Morresi A, Del Vecchio P, Sassi P. Solvation properties of raft-like model membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:183052. [PMID: 31449802 DOI: 10.1016/j.bbamem.2019.183052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/25/2019] [Accepted: 08/02/2019] [Indexed: 12/15/2022]
Abstract
Dimethyl sulfoxide (DMSO) is a universal water-soluble solvent widely used in many biotechnological and medical applications, such as cells cryopreservation, and for the treatment of different human diseases (e.g. amyloidosis). Despite the great number of reported studies, the effects of DMSO on the physico-chemical properties of biological membranes are poorly understood. Often, these studies are limited to model membranes composed of phosphatidylcholines (PCs) and cholesterol (Chol). In this work, we explored the effect of DMSO on liposomes composed of the natural egg sphingomyelin (ESM) and Chol as raft-like model membranes. With a multi-technique approach we probe the structure and the thermal stability of ESM/Chol bilayer at different Chol mole fractions. In particular, we investigate the ESM-solvent interactions to clarify the role of DMSO in perturbing the solvating conditions of lipid vesicles and show that the addition of DMSO increases the thermal stability of vesicles. An increase of transition temperature, a decrease of both enthalpy and entropy as well as a decrease of the cooperativity of the gel to liquid phase transition are observed at 0.1 DMSO mole fraction. Fluorescence experiments with the probe Laurdan and FTIR spectra strongly indicate that DMSO exerts a dehydration effect on the membrane. Besides, FTIR measurements with tungsten hexacarbonyl, in combination with fluorescence data of the probe NBD-PE, indicate that DMSO promotes the formation of a highly packed membrane by reducing the thickness of the membrane.
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Affiliation(s)
- Beatrice Gironi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Rosario Oliva
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 21, 80126 Napoli, Italy
| | - Luigi Petraccone
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 21, 80126 Napoli, Italy
| | - Marco Paolantoni
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Assunta Morresi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Pompea Del Vecchio
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 21, 80126 Napoli, Italy.
| | - Paola Sassi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy; Centro di Eccellenza sui Materiali Innovativi Nanostrutturati (CEMIN), Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy.
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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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15
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Saaka Y, Allen DT, Luangwitchajaroen Y, Shao Y, Campbell RA, Lorenz CD, Lawrence MJ. Towards optimised drug delivery: structure and composition of testosterone enanthate in sodium dodecyl sulfate monolayers. SOFT MATTER 2018; 14:3135-3150. [PMID: 29629469 DOI: 10.1039/c7sm01893b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Surface tension and specular neutron reflectivity measurements have been used, for the first time to systematically study both the interfacial structure and composition of monolayers of the soluble surfactant, sodium dodecyl sulfate containing a low-dose, poorly water soluble drug, testosterone enanthate. Modelling of the specular neutron reflectivity data suggests that the hydrophobic testosterone enanthate was adsorbed in the C12 hydrophobic tail region of the surfactant monolayer, regardless of the concentration of surfactant at the interface and whether or not additional drug was added to the interface. The location of the hydrophobic drug in the tail region of the surfactant monolayer is supported by the results of classical, large-scale molecular dynamics simulations. The thickness of the surfactant monolayer obtained, in the presence and absence of drug, using molecular dynamics simulations was in good agreement with the corresponding values obtained from the specular neutron reflectivity measurements. The stoichiometry of surfactant:drug at the air-water interface at sodium dodecyl sulfate concentrations above the critical micelle concentration was determined from specular neutron reflectivity measurements to be approximately 3 : 1, and remained constant after the spreading of further testosterone enanthate at the interface. Significantly, this stoichiometry was the same as that obtained in the micelles from bulk solubilisation studies. Important insights into the preferred location of drug in surfactant monolayers at the air-water interface as well as its effect on the structure of the monolayer have been obtained from our combined use of experimental and simulation techniques.
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Affiliation(s)
- Yussif Saaka
- Institute of Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, Franklin-Wilkins Building, Stamford Street, London SE1 9NH, UK
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16
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Allen DT, Damestani N, Saaka Y, Lawrence MJ, Lorenz CD. Interaction of testosterone-based compounds with dodecyl sulphate monolayers at the air–water interface. Phys Chem Chem Phys 2018. [DOI: 10.1039/c7cp07611h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The encapsulation of testosterone enanthate into a sodium dodecyl sulphate monolayer.
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Affiliation(s)
- Daniel T. Allen
- Biological Physics & Soft Matter Group
- Department of Physics
- King's College London
- London WC2R 2LS
- UK
| | - Nikou Damestani
- Biological Physics & Soft Matter Group
- Department of Physics
- King's College London
- London WC2R 2LS
- UK
| | - Yussif Saaka
- Pharmaceutical Biophysics Group
- Institute of Pharmaceutical Science
- King's College London
- London SE1 9NH
- UK
| | - M. Jayne Lawrence
- Division of Pharmacy and Optometry
- School of Health Sciences
- The University of Manchester
- Manchester M13 9PT
- UK
| | - Christian D. Lorenz
- Biological Physics & Soft Matter Group
- Department of Physics
- King's College London
- London WC2R 2LS
- UK
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17
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Gillams RJ, Lorenz CD, McLain SE. Comparative atomic-scale hydration of the ceramide and phosphocholine headgroup in solution and bilayer environments. J Chem Phys 2017; 144:225101. [PMID: 27306021 DOI: 10.1063/1.4952444] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Previous studies have used neutron diffraction to elucidate the hydration of the ceramide and the phosphatidylcholine headgroup in solution. These solution studies provide bond-length resolution information on the system, but are limited to liquid samples. The work presented here investigates how the hydration of ceramide and phosphatidylcholine headgroups in a solution compares with that found in a lipid bilayer. This work shows that the hydration patterns seen in the solution samples provide valuable insight into the preferential location of hydrating water molecules in the bilayer. There are certain subtle differences in the distribution, which result from a combination of the lipid conformation and the lipid-lipid interactions within the bilayer environment. The lipid-lipid interactions in the bilayer will be dependent on the composition of the bilayer, whereas the restricted exploration of conformational space is likely to be applicable in all membrane environments. The generalized description of hydration gathered from the neutron diffraction studies thus provides good initial estimation for the hydration pattern, but this can be further refined for specific systems.
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Affiliation(s)
- Richard J Gillams
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Christian D Lorenz
- Department of Physics, King's College London, London WC2R 2LS, United Kingdom
| | - Sylvia E McLain
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
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18
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Schrader AM, Cheng CY, Israelachvili JN, Han S. Communication: Contrasting effects of glycerol and DMSO on lipid membrane surface hydration dynamics and forces. J Chem Phys 2017; 145:041101. [PMID: 27475340 DOI: 10.1063/1.4959904] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Glycerol and dimethyl sulfoxide (DMSO) are commonly used cryoprotectants in cellular systems, but due to the challenges of measuring the properties of surface-bound solvent, fundamental questions remain regarding the concentration, interactions, and conformation of these solutes at lipid membrane surfaces. We measured the surface water diffusivity at gel-phase dipalmitoylphosphatidylcholine (DPPC) bilayer surfaces in aqueous solutions containing ≤7.5 mol. % of DMSO or glycerol using Overhauser dynamic nuclear polarization. We found that glycerol similarly affects the diffusivity of water near the bilayer surface and that in the bulk solution (within 20%), while DMSO substantially increases the diffusivity of surface water relative to bulk water. We compare these measurements of water dynamics with those of equilibrium forces between DPPC bilayers in the same solvent mixtures. DMSO greatly decreases the range and magnitude of the repulsive forces between the bilayers, whereas glycerol increases it. We propose that the differences in hydrogen bonding capability of the two solutes leads DMSO to dehydrate the lipid head groups, while glycerol affects surface hydration only as much as it affects the bulk water properties. The results suggest that the mechanism of the two most common cryoprotectants must be fundamentally different: in the case of DMSO by decoupling the solvent from the lipid surface, and in the case of glycerol by altering the hydrogen bond structure and intermolecular cohesion of the global solvent, as manifested by increased solvent viscosity.
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Affiliation(s)
- Alex M Schrader
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA
| | - Chi-Yuan Cheng
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA
| | - Jacob N Israelachvili
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA
| | - Songi Han
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA
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19
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Jagalski V, Barker R, Topgaard D, Günther-Pomorski T, Hamberger B, Cárdenas M. Biophysical study of resin acid effects on phospholipid membrane structure and properties. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1858:2827-2838. [PMID: 27544924 DOI: 10.1016/j.bbamem.2016.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 08/12/2016] [Accepted: 08/15/2016] [Indexed: 10/21/2022]
Abstract
Hydrophobic resin acids (RAs) are synthesized by conifer trees as part of their defense mechanisms. One of the functions of RAs in plant defense is suggested to be the perturbation of the cellular membrane. However, there is a vast diversity of chemical structures within this class of molecules, and there are no clear correlations to the molecular mechanisms behind the RA's toxicity. In this study we unravel the molecular interactions of the three closely related RAs dehydroabietic acid, neoabietic acid, and the synthetic analogue dichlorodehydroabietic acid with dipalmitoylphosphatidylcholine (DPPC) model membranes and the polar lipid extract of soybeans. The complementarity of the biophysical techniques used (NMR, DLS, NR, DSC, Cryo-TEM) allowed correlating changes at the vesicle level with changes at the molecular level and the co-localization of RAs within DPPC monolayer. Effects on DPPC membranes are correlated with the physical chemical properties of the RA and their toxicity.
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Affiliation(s)
- Vivien Jagalski
- Nano Science Center and Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Robert Barker
- Institute Laue Langevin, 71 avenue de Matyrs, CS, 20156, 38042 Grenoble Cedex 9, France
| | - Daniel Topgaard
- Division of Physical Chemistry, Department of Chemistry, Lund University, Sweden
| | - Thomas Günther-Pomorski
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Björn Hamberger
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marité Cárdenas
- Nano Science Center and Department of Chemistry, University of Copenhagen, Copenhagen, Denmark; Biofilm - Research Center for Biointerfaces and Department of Biomedical Science, Malmö University, Malmö, Sweden.
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20
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Wojciechowski K, Orczyk M, Gutberlet T, Brezesinski G, Geue T, Fontaine P. On the Interaction between Digitonin and Cholesterol in Langmuir Monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:9064-9073. [PMID: 27518122 DOI: 10.1021/acs.langmuir.6b01737] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this article, we describe the effect of a highly hemolytic saponin, digitonin, on model lipids cholesterol and dipalmitoylphosphatidylcholine (DPPC) using a combination of tensiometric (surface pressure and dilatational surface elasticity), spectroscopic (infrared reflection absorption spectroscopy, IRRAS), microscopic (fluorescence microscopy), and scattering techniques (neutron reflectivity, NR, and grazing incidence X-ray diffraction, GIXD). The monolayers of individual lipids and their 10:9 (mol/mol) mixture were exposed to an aqueous solution of digitonin (10(-4) M) by subphase exchange using a setup developed recently in our laboratory. The results confirm that digitonin can adsorb onto both bare and lipid-covered water-air interfaces. In the case of DPPC, a relatively weak interaction can be observed, but the presence of cholesterol drastically enhances the effect of digitonin. The latter is shown to dissociate the weak cholesterol-DPPC complexes and to bind cholesterol in an additional layer attached to the original lipid monolayer.
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Affiliation(s)
- Kamil Wojciechowski
- Faculty of Chemistry, Warsaw University of Technology , Noakowskiego 3, 00-664 Warsaw, Poland
| | - Marta Orczyk
- Faculty of Chemistry, Warsaw University of Technology , Noakowskiego 3, 00-664 Warsaw, Poland
| | - Thomas Gutberlet
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85748 Garching, Germany
| | - Gerald Brezesinski
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, Potsdam, Germany
| | - Thomas Geue
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute , WHGA/110, 5232 Villigen - PSI, Switzerland
| | - Philippe Fontaine
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP48, Gif-sur-Yvette Cedex, France
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21
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Complexation of phospholipids and cholesterol by triterpenic saponins in bulk and in monolayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:363-73. [PMID: 26654784 DOI: 10.1016/j.bbamem.2015.12.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/01/2015] [Indexed: 01/23/2023]
Abstract
The interactions between three triterpene saponins: α-hederin, hederacoside C and ammonium glycyrrhizate with model lipids: cholesterol and dipalmitoylphosphatidylcholine (DPPC) are described. The oleanolic acid-type saponins (α-hederin and hederacoside C) were shown to form 1:1 complexes with lipids in bulk, characterized by stability constants in the range (4.0±0.2)·10(3)-(5.0±0.4)·10(4) M(-1). The complexes with cholesterol are generally stronger than those with DPPC. On the contrary, ammonium glycyrrhizate does not form complexes with any of the lipids in solution. The saponin-lipid interactions were also studied in a confined environment of Langmuir monolayers of DPPC and DPPC/cholesterol with the saponins present in the subphase. A combined monolayer relaxation, surface dilational rheology, fluorescence microscopy and neutron reflectivity (NR) study showed that all three saponins are able to penetrate pure DPPC and mixed DPPC/cholesterol monolayers. Overall, the effect of the saponins on the model lipid monolayers does not fully correlate with the lipid-saponin complex formation in the homogeneous solution. The best correlation was found for α-hederin, for which even the preference for cholesterol over DPPC observed in bulk is well reflected in the monolayer studies and the literature data on its membranolytic activity. Similarly, the lack of interaction of ammonium glycyrrhizate with both lipids is evident equally in bulk and monolayer experiments, as well as in its weak membranolytic activity. The combined bulk and monolayer results are discussed in view of the role of confinement in modulating the saponin-lipid interactions and possible mechanism of membranolytic activity of saponins.
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22
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Clark GA, Henderson JM, Heffern C, Akgün B, Majewski J, Lee KYC. Synergistic Interactions of Sugars/Polyols and Monovalent Salts with Phospholipids Depend upon Sugar/Polyol Complexity and Anion Identity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:12688-12698. [PMID: 26496486 DOI: 10.1021/acs.langmuir.5b02815] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We found that interactions of dipalmitoylphosphatidylcholine (DPPC) lipid monolayers with sugars are influenced by addition of NaCl. This work is of general importance in understanding how sugar-lipid-salt interactions impact biological systems. Using Langmuir isothermal compressions, fluorescence microscopy, atomic force microscopy, and neutron reflectometry, we examined DPPC monolayers upon addition of sugars/polyols and/or monovalent salts. Sugar-lipid interactions in the presence of NaCl increased with increasing complexity of the sugar/polyol in the order glycerol ≪ glucose < trehalose. When the anion was altered in the series NaF, NaCl, and NaBr, only minor differences were observed. When comparing LiCl, NaCl, and KCl, sodium chloride had the greatest influence on glucose and trehalose interactions with DPPC. We propose that heterogeneity created by cation binding allows for sugars to bind the lipid headgroups. While cation binding increases in the order K(+) < Na(+) < Li(+), lithium ions may also compete with glucose for binding sites. Thus, both cooperative and competitive factors contribute to the overall influence of salts on sugar-lipid interactions.
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Affiliation(s)
- Ginevra A Clark
- Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
| | - J Michael Henderson
- Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
| | - Charles Heffern
- Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
| | - Bülent Akgün
- Department of Chemistry, Bogazici University , Bebek, Istanbul 34342, Turkey
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United States
- Department of Materials Science and Engineering, University of Maryland , College Park, Maryland 20742, United States
| | - Jaroslaw Majewski
- Los Alamos Neutron Scattering Center/MPA/CINT, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
- Department of Chemical Engineering, University of California , Davis, California 95616, United States
| | - Ka Yee C Lee
- Department of Chemistry, Institute for Biophysical Dynamics, James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
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23
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Miguel V, Defonsi Lestard ME, Tuttolomondo ME, Díaz SB, Altabef AB, Puiatti M, Pierini AB. Molecular view of the interaction of S-methyl methanethiosulfonate with DPPC bilayer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:38-46. [PMID: 26476106 DOI: 10.1016/j.bbamem.2015.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 10/07/2015] [Accepted: 10/13/2015] [Indexed: 12/27/2022]
Abstract
We present molecular dynamics (MD) simulation studies of the interaction of a chemo preventive and protective agent, S-methyl methanethiosulfonate (MMTS), with a model bilayer of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). We analyzed and compared its diffusion mechanisms with the related molecule dimethyl sulfoxide (DMSO). We obtained spatially resolved free energy profiles of MMTS partition into a DPPC bilayer in the liquid-crystalline phase through potential of mean force (PMF) calculations using an umbrella sampling technique. These profiles showed a minimum for MMTS close to the carbonyl region of DPPC. The location of MMTS molecules in the DPPC bilayer observed in the MD was confirmed by previous SERS studies. We decomposed PMF profiles into entropic and enthalpic contributions. These results showed that the driving force for the partitioning of MMTS into the upper region of DPPC is driven by a favorable entropy change while partitioning into the acyl chains is driven by enthalpy. On the other hand, the partition of DMSO into the membrane is not favored, and is driven by entropy instead of enthalpy. Free diffusion MD simulations using all atom and coarse grained (CG) models of DPPC in presence of MMTS were used to analyze the effect of DPPC-MMTS interaction. Density profiles showed that MMTS locates preferentially in the carbonyl region, as expected according to the PMF profile and the experimental evidence. MMTS presented two differential effects over the packing of DPPC hydrocarbonate chains at low or at high molar ratios. An ordering effect was observed when a CG MMTS model was used. Finally, free diffusion MD and PMF decomposition for DMSO were used for comparison.
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Affiliation(s)
- Virginia Miguel
- INFIQC-CONICET, Instituto de Investigaciones en Físico-Química de Córdoba, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba, Argentina
| | - Maria E Defonsi Lestard
- INQUINOA-CONICET, Cátedra de Fisicoquímica I, Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN S. M. de Tucumán, Argentina
| | - María E Tuttolomondo
- INQUINOA-CONICET, Cátedra de Fisicoquímica I, Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN S. M. de Tucumán, Argentina
| | - Sonia B Díaz
- INQUINOA-CONICET, Cátedra de Fisicoquímica I, Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN S. M. de Tucumán, Argentina
| | - Aida Ben Altabef
- INQUINOA-CONICET, Cátedra de Fisicoquímica I, Instituto de Química Física, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, San Lorenzo 456, T4000CAN S. M. de Tucumán, Argentina
| | - Marcelo Puiatti
- INFIQC-CONICET, Instituto de Investigaciones en Físico-Química de Córdoba, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba, Argentina.
| | - Adriana B Pierini
- INFIQC-CONICET, Instituto de Investigaciones en Físico-Química de Córdoba, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba, Argentina
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24
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Jagalski V, Barker RD, Thygesen MB, Gotfryd K, Krüger MB, Shi L, Maric S, Bovet N, Moulin M, Haertlein M, Pomorski TG, Loland CJ, Cárdenas M. Grafted biomembranes containing membrane proteins--the case of the leucine transporter. SOFT MATTER 2015; 11:7707-7711. [PMID: 26325086 DOI: 10.1039/c5sm01490e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Here, we bind the sodium dependent amino acid transporter on nitrilotriacetic acid/polyethylene glycol functionalized gold sensors in detergents and perform a detergent-lipid exchange with phosphatidylcholine. We characterize the LeuT structure in the adsorbed film by magnetic contrast neutron reflection using the predicted model from molecular dynamic simulations.
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Affiliation(s)
- Vivien Jagalski
- Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, DK 2100, Copenhagen, Denmark.
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