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Ciumac D, Gong H, Campbell RA, Campana M, Xu H, Lu JR. Structural elucidation upon binding of antimicrobial peptides into binary mixed lipid monolayers mimicking bacterial membranes. J Colloid Interface Sci 2021; 598:193-205. [PMID: 33901846 DOI: 10.1016/j.jcis.2021.04.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/07/2021] [Accepted: 04/09/2021] [Indexed: 11/28/2022]
Abstract
HYPOTHESIS Antimicrobial peptides (AMPs) kill microorganisms by causing structural damage to bacterial membranes. Different microorganisms often require a different type and concentration of an AMP to achieve full microbial killing. We hypothesise that the difference is caused by different membrane structure and composition. EXPERIMENTS Given the complexities of bacterial membranes, we have used monolayers of the binary DPPG/TMCL mixture to mimic the cytoplasmic membrane of Gram-positive bacteria and the binary DPPG/DPPE mixture to mimic the cytoplasmic membrane of Gram-negative bacteria, where DPPG, TMCL and DPPE stand for 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol), 1',3'-bis[1,2-dimyristoyl-sn-glycero-3-phospho]-sn-glycerol, and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine, respectively. A Langmuir trough was specially designed to control the spread lipid monolayers and facilitate neutron reflectivity measurements. FINDINGS Surface pressure-area isotherm analysis revealed that all binary lipid systems mix non-ideally, but mixing is thermodynamically favoured. An increase in the surface pressure encourages demixing, resulting in phase separation and formation of clusters. Neutron reflectivity measurements were undertaken to study the binding of an antimicrobial peptide G(IIKK)4-I-NH2 (G4) to the binary DPPG/TMCL and DPPG/DPPE monolayer mixtures at the molar ratios of 6/4 and 3/7, respectively. The results revealed stronger binding and penetration of G4 to the DPPG/TMCL monolayer, indicating greater affinity of the antimicrobial peptide due to the electrostatic interaction and more extensive penetration into the more loosely packed lipid film. This work helps explain how AMPs attack different bacterial membranes, and the results are discussed in the context of other lipid models and antibacterial studies.
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Affiliation(s)
- Daniela Ciumac
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, Manchester M13 9PL, UK
| | - Haoning Gong
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, Manchester M13 9PL, UK
| | - Richard A Campbell
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS-20156, 38042 Grenoble, France; Division of Pharmacy and Optometry, University of Manchester, Oxford Road, Stopford Building, Manchester M13 9PT, UK
| | - Mario Campana
- ISIS Neutron Facility, STFC, Chilton, Didcot OX11 0QZ, UK
| | - Hai Xu
- Centre for Bioengineering and Biotechnology, China University of Petroleum, Qingdao, China
| | - Jian R Lu
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, Manchester M13 9PL, UK.
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2
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Interactions of l-arginine with Langmuir monolayers of common phospholipids at the air-water interface. Chem Phys Lipids 2021; 235:105054. [PMID: 33508301 DOI: 10.1016/j.chemphyslip.2021.105054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 01/06/2021] [Accepted: 01/21/2021] [Indexed: 12/20/2022]
Abstract
The interactions of l-arginine (l-arg) with Langmuir monolayers of three most common phospholipids, which are sodium salt of dipalmitoylphosphatidylglycerol (DPPG), dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylethanolamine (DPPE), have been investigated at the air-water interface. The surface pressure-area (π-A) isotherms of these monolayers have been measured with a film balance and monolayer morphology has been observed by a Brewster angle microscopy (BAM). The DPPG monolayers on pure water do not show any phase transition but show irregular shaped condensed phases formed just after evaporation of the solvent at 20 °C. However, this monolayer on l-arg solution subphase indicates a first-order phase transition from liquid expanded to liquid condensed (LE-LC) phases and forms LC domains at the same temperature. With an increase in the l-arg concentration in the subphase up to 5.0 × 10-4 M, the π-A shows an overall increasingly greater expansion in the molecular area. All of the π-A isotherms recorded on ≥5.0 × 10-4 M l-arg solution subphases almost coincide with each other. These changes in the phase behavior have been explained by the fact that l-arg having guanidinium cationic group undergoes strong hydrogen bonding interaction with the anionic phosphatidylglycerol (PG-) head group. The bonding between two molecules is further strengthened by electrostatic attraction between cationic l-arg and anionic PG- ions. The BAM observation of the monolayer morphology supports this explanation. On the other hand, a very negligible interaction has been observed between l-arg and DPPC or DPPE monolayers. The π-A isotherms in the presence of l-arg for both the amphiphiles show a very little expansion only in the LE phase region, but coincide in the so called solid phase region. The monolayer morphology of both the monolayers also supports these results. This little effect of expansion in the LE region may be explained by the ion-pair formation between cationic l-arg and anionic head groups in the monolayers at lower pressures. However, due to compression at high pressure, the l-arg molecules are squeezed out from the amphiphile head groups.
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3
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Wölk C, Youssef H, Guttenberg T, Marbach H, Vizcay‐Barrena G, Shen C, Brezesinski G, Harvey RD. Phase Diagram for a Lysyl-Phosphatidylglycerol Analogue in Biomimetic Mixed Monolayers with Phosphatidylglycerol: Insights into the Tunable Properties of Bacterial Membranes. Chemphyschem 2020; 21:702-706. [PMID: 32065707 PMCID: PMC7216935 DOI: 10.1002/cphc.202000026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/12/2020] [Indexed: 12/13/2022]
Abstract
Ion pairing between the major phospholipids of the Staphylococcus aureus plasma membrane (phosphatidylglycerol - PG and lysyl-phosphatidylglycerol - LPG) confers resistance to antimicrobial peptides and other antibiotics. We developed 3adLPG, a stable synthetic analogue which can substitute for the highy-labile native LPG, in biophysical experiments examining the membrane-protecting role of lipid ion pairing, in S. aureus and other important bacteria. Here we examine the surface charge and lipid packing characteristics of synthetic biomimetic mixtures of DPPG and DP3adLPG in Langmuir monolayers, using a combination of complementary surface-probing techniques such as infrared reflection-absorption spectroscopy and grazing-incidence x-ray diffraction. The resultant phase diagram for the ion paired lipids sheds light on the mixing behavior of lipids in monolayer models of resistant phenotype bacterial membranes, and provides a platform for future biophysical studies.
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Affiliation(s)
- Christian Wölk
- Institute of PharmacyLeipzig UniversityBrüderstraße 3404103LeipzigGermany
| | - Hala Youssef
- Department of Chemistry and BiochemistryConcordia University7141 Sherbrooke Street WestMontrealCanada
| | - Thomas Guttenberg
- Institute of PharmacyMartin-Luther-University Halle-WittenbergKurt-Mothes-Str. 306120Halle (Saale)Germany
| | - Helene Marbach
- Institute of MicrobiologyUniversity of Veterinary MedicineVeterinärplatz 11210ViennaAustria
| | - Gema Vizcay‐Barrena
- Centre for Ultrastructural ImagingKing's College LondonGuy's CampusLondonSE1 1ULUK
| | - Chen Shen
- DESY Photon Science22607HamburgGermany
| | - Gerald Brezesinski
- Max Planck Institute of Colloids and InterfacesAm Mühlenberg 114476PotsdamGermany
| | - Richard D. Harvey
- Institute of PharmacyMartin-Luther-University Halle-WittenbergKurt-Mothes-Str. 306120Halle (Saale)Germany
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4
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Double layer electrostatics of heterogeneous surfaces with circle phase contours. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.123606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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5
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McCluskey AR, Sanchez-Fernandez A, Edler KJ, Parker SC, Jackson AJ, Campbell RA, Arnold T. Bayesian determination of the effect of a deep eutectic solvent on the structure of lipid monolayers. Phys Chem Chem Phys 2019; 21:6133-6141. [DOI: 10.1039/c9cp00203k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A novel reflectometry analysis method reveals the structure of lipid monolayers at the air-DES interface.
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Affiliation(s)
| | | | | | | | - Andrew J. Jackson
- European Spallation Source
- SE-211 00 Lund
- Sweden
- Department of Physical Chemistry
- Lund University
| | - Richard A. Campbell
- Division of Pharmacy and Optometry
- University of Manchester
- Manchester
- UK
- Institut Laue-Langevin
| | - Thomas Arnold
- Department of Chemistry
- University of Bath
- Bath
- UK
- Diamond Light Source
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6
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A combined FTIR and DSC study on the bilayer-stabilising effect of electrostatic interactions in ion paired lipids. Colloids Surf B Biointerfaces 2018; 169:298-304. [DOI: 10.1016/j.colsurfb.2018.05.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 05/11/2018] [Accepted: 05/14/2018] [Indexed: 11/23/2022]
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7
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Hädicke A, Schwieger C, Blume A. Cospreading of Anionic Phospholipids with Peptides of the Structure (KX) 4K at the Air-Water Interface: Influence of Lipid Headgroup Structure and Hydrophobicity of the Peptide on Monolayer Behavior. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:12204-12217. [PMID: 28968121 DOI: 10.1021/acs.langmuir.7b02255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Mixtures of anionic phospholipids (PG, PA, PS, and CL) with cationic peptides were cospread from a common organic solvent at the air-water interface. The compression of the mixed film was combined with epifluorescence microscopy or infrared reflection adsorption spectroscopy (IRRAS) to gain information on the interactions of the peptide with the different lipids. To evaluate the influence of the amino acid X of peptides with the sequence (KX)4K on the binding, 1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol (DPPG) was mixed with different peptides with increasing hydrophobicity of the uncharged amino acid X. The monolayer isotherms of DPPG/(KX)4K mixtures show an increased area for the lift-off due to incorporation of the peptide into the liquid-expanded (LE) state of the lipid. The surface pressure for the transition from LE to the liquid-condensed (LC) state is slightly increased for peptides with amino acids X with moderate hydrophobicity. For the most hydrophobic peptide (KL)4K two plateaus are seen at a charge ratio PG to K of 5:1, and a strongly increased transition pressure is observed for a charge ratio of 1:1. Epifluorescence microscopy images and infrared spectroscopy show that the lower plateau corresponds to the LE-LC phase transition of the lipid. The upper plateau is connected with a squeeze-out of the peptide into the subphase. To test the influence of the lipid headgroup structure on peptide binding (KL)4K was cospread with different anionic phospholipids. The shift of the isotherm to larger areas for lift-off and to higher surface pressure for the LE-LC phase transition was observed for all tested anionic lipids. Epifluorescence microscopy reveals the formation of LC domains with extended filaments indicating a decrease in line tension due to accumulation of the peptides at the LC-domain boundaries. This effect depends on the size of the headgroup of the anionic phospholipid.
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Affiliation(s)
- André Hädicke
- Institute of Chemistry , MLU Halle-Wittenberg, von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany
| | - Christian Schwieger
- Institute of Chemistry , MLU Halle-Wittenberg, von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany
| | - Alfred Blume
- Institute of Chemistry , MLU Halle-Wittenberg, von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany
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8
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Xu GQ, Hao CC, Zhang L, Chen S, Sun RG. Dynamic Behaviors and Morphology Change of Anionic Phospholipid DPPG Monolayer Caused by Bovine Serum Albumin at Air-Water Interface. CHINESE J CHEM PHYS 2017. [DOI: 10.1063/1674-0068/30/cjcp1703029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Guo-qing Xu
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
| | - Chang-chun Hao
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
| | - Lei Zhang
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
| | - Shi Chen
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
| | - Run-guang Sun
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
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9
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Selladurai SL, Miclette Lamarche R, Schmidt R, DeWolf CE. Model Lung Surfactant Films: Why Composition Matters. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10767-10775. [PMID: 27641759 DOI: 10.1021/acs.langmuir.6b02945] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Lung surfactant replacement therapies, Survanta and Infasurf, and two lipid-only systems both containing saturated and unsaturated phospholipids and one containing additional palmitic acid were used to study the impact of buffered saline on the surface activity, morphology, rheology, and structure of Langmuir monolayer model membranes. Isotherms and Brewster angle microscopy show that buffered saline subphases induce a film expansion, except when the cationic protein, SP-B, is present in sufficient quantities to already screen electrostatic repulsion, thus limiting the effect of changing pH and adding counterions. Grazing incidence X-ray diffraction results indicate an expansion not only of the liquid expanded phase but also an expansion of the lattice of the condensed phase. The film expansion corresponded in all cases with a significant reduction in the viscosity and elasticity of the films. The viscoelastic parameters are dominated by liquid expanded phase properties and do not appear to be dependent on the structure of the condensed phase domains in a phase separated film. The results highlight that the choice of subphase and film composition is important for meaningful interpretations of measurements using model systems.
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Affiliation(s)
- Sahana L Selladurai
- Department of Chemistry and Biochemistry and Centre for NanoScience Research, Concordia University , 7141 Sherbrooke Street West, Montreal, Canada H4B 1R6
| | - Renaud Miclette Lamarche
- Department of Chemistry and Biochemistry and Centre for NanoScience Research, Concordia University , 7141 Sherbrooke Street West, Montreal, Canada H4B 1R6
| | - Rolf Schmidt
- Department of Chemistry and Biochemistry and Centre for NanoScience Research, Concordia University , 7141 Sherbrooke Street West, Montreal, Canada H4B 1R6
| | - Christine E DeWolf
- Department of Chemistry and Biochemistry and Centre for NanoScience Research, Concordia University , 7141 Sherbrooke Street West, Montreal, Canada H4B 1R6
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10
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Membrane binding of peptide models for early stages of amyloid formation: Lipid packing counts more than charge. Chem Phys Lipids 2016; 198:28-38. [DOI: 10.1016/j.chemphyslip.2016.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 02/04/2016] [Accepted: 02/27/2016] [Indexed: 11/17/2022]
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11
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Souza AL, Ceridório LF, Paula GF, Mattoso LH, Oliveira ON. Understanding the biocide action of poly(hexamethylene biguanide) using Langmuir monolayers of dipalmitoyl phosphatidylglycerol. Colloids Surf B Biointerfaces 2015; 132:117-21. [DOI: 10.1016/j.colsurfb.2015.05.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 05/07/2015] [Accepted: 05/11/2015] [Indexed: 01/16/2023]
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12
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Caruso B, Villarreal M, Reinaudi L, Wilke N. Inter-Domain Interactions in Charged Lipid Monolayers. J Phys Chem B 2014; 118:519-29. [DOI: 10.1021/jp408053a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Benjamín Caruso
- Centro de Investigaciones en Química Biológica de Córdoba
(CIQUIBIC), Dpto. de Química Biológica, and ‡Instituto de Investigaciones
en Físico-Química de Córdoba (INFIQC), Dpto.
de Matemática y Física, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Pabellón Argentina, Ciudad Universitaria, X5000HUA Córdoba, Argentina
| | - Marcos Villarreal
- Centro de Investigaciones en Química Biológica de Córdoba
(CIQUIBIC), Dpto. de Química Biológica, and ‡Instituto de Investigaciones
en Físico-Química de Córdoba (INFIQC), Dpto.
de Matemática y Física, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Pabellón Argentina, Ciudad Universitaria, X5000HUA Córdoba, Argentina
| | - Luis Reinaudi
- Centro de Investigaciones en Química Biológica de Córdoba
(CIQUIBIC), Dpto. de Química Biológica, and ‡Instituto de Investigaciones
en Físico-Química de Córdoba (INFIQC), Dpto.
de Matemática y Física, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Pabellón Argentina, Ciudad Universitaria, X5000HUA Córdoba, Argentina
| | - Natalia Wilke
- Centro de Investigaciones en Química Biológica de Córdoba
(CIQUIBIC), Dpto. de Química Biológica, and ‡Instituto de Investigaciones
en Físico-Química de Córdoba (INFIQC), Dpto.
de Matemática y Física, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Pabellón Argentina, Ciudad Universitaria, X5000HUA Córdoba, Argentina
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13
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Penetration of milk-derived antimicrobial peptides into phospholipid monolayers as model biomembranes. Biochem Res Int 2013; 2013:914540. [PMID: 24455264 PMCID: PMC3877611 DOI: 10.1155/2013/914540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/27/2013] [Accepted: 08/27/2013] [Indexed: 12/18/2022] Open
Abstract
Three antimicrobial peptides derived from bovine milk proteins were examined with regard to penetration into insoluble monolayers formed with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt (DPPG). Effects on surface pressure (Π) and electric surface potential (ΔV) were measured, Π with a platinum Wilhelmy plate and ΔV with a vibrating plate. The penetration measurements were performed under stationary diffusion conditions and upon the compression of the monolayers. The two type measurements showed greatly different effects of the peptide-lipid interactions. Results of the stationary penetration show that the peptide interactions with DPPC monolayer are weak, repulsive, and nonspecific while the interactions with DPPG monolayer are significant, attractive, and specific. These results are in accord with the fact that antimicrobial peptides disrupt bacteria membranes (negative) while no significant effect on the host membranes (neutral) is observed. No such discrimination was revealed from the compression isotherms. The latter indicate that squeezing the penetrant out of the monolayer upon compression does not allow for establishing the penetration equilibrium, so the monolayer remains supersaturated with the penetrant and shows an under-equilibrium orientation within the entire compression range, practically.
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14
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Torrano AA, Pereira ÂS, Oliveira ON, Barros-Timmons A. Probing the interaction of oppositely charged gold nanoparticles with DPPG and DPPC Langmuir monolayers as cell membrane models. Colloids Surf B Biointerfaces 2013; 108:120-6. [PMID: 23528608 DOI: 10.1016/j.colsurfb.2013.02.014] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 02/08/2013] [Accepted: 02/11/2013] [Indexed: 12/19/2022]
Abstract
The growing use of nanoparticles in a variety of applications calls for detailed studies of their toxicology, which in turn require understanding the interactions between nanoparticles and living cells. Since simulating the interaction with real cell membranes is rather complex, Langmuir monolayers (LMs) have been used to mimic the first barrier encountered by a nanoparticle as it approaches a biological membrane to assess molecular-level interactions. In this study, we show how oppositely charged gold nanoparticles (Au-NPs) interact with monolayers of the zwitterionic dipalmitoylphosphatidyl choline (DPPC) and negatively charged dipalmitoylphosphatidyl glycerol (DPPG). The monolayers were spread on subphases containing two concentrations of either negatively charged Au-NPs coated with citrate anions or positively charged Au-NPs functionalized with the cationic polyelectrolyte poly(allylamine hydrochloride) (PAH). For DPPG, electrostatic effects dominated which depended strongly on the NPs capping agent, being obviously larger for the positive nanoparticles. The in-plane elasticity for DPPG monolayers within the surface pressure range corresponding to real cell membranes increased with adsorption of positively charged NPs, but decreased with the negative ones. For the zwitterionic DPPC, on the other hand, significant effects only occurred for negatively charged NPs, including a decrease in elasticity. Therefore, it is concluded that the nature, namely the charge of the capping agents, is crucial for the interaction of charged NPs with the cell membrane.
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Affiliation(s)
- Adriano A Torrano
- Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
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15
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Abstract
AbstractAbstract The interaction between Mg2+ and a phosphatidylcholine (lecithin, L) monolayer at the air/water interface was investigated. Surface tension measurements (Langmuir method) of phosphatidylcholine monolayers as a function of Mg2+ concentration were carried out at 22°C using a Teflon trough and a Nima 9000 tensiometer. Interactions between phosphatidylcholine and Mg2+ result in significant deviations from additivity. An equilibrium theory was developed to obtain the stability constants and areas occupied by one molecule of LMg+ and L2Mg. The stability constants were K 1 = 9.95×102 m2 mol−1 and K 2 = 3.87×104 m2 mol−1. The area occupied by LMg+ is 77 Å2 molecule−1, while that occupied by L2Mg is 109 Å2 molecule−1. The Gibbs free energies of complexation for LMg+ and L2Mg are −16.91 ± 0.51 and −25.88 ± 0.76 kJ mol−1. Graphical abstract
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16
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Griesbauer J, Bössinger S, Wixforth A, Schneider MF. Simultaneously propagating voltage and pressure pulses in lipid monolayers of pork brain and synthetic lipids. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:061909. [PMID: 23367978 DOI: 10.1103/physreve.86.061909] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Revised: 07/25/2012] [Indexed: 06/01/2023]
Abstract
Hydrated interfaces are ubiquitous in biology and appear on all length scales from ions and individual molecules to membranes and cellular networks. In vivo, they comprise a high degree of self-organization and complex entanglement, which limits their experimental accessibility by smearing out the individual phenomenology. The Langmuir technique, however, allows the examination of defined interfaces, the controllable thermodynamic state of which enables one to explore the proper state diagrams. Here we demonstrate that voltage and pressure pulses simultaneously propagate along monolayers comprised of either native pork brain or synthetic lipids. The excitation of pulses is conducted by the application of small droplets of acetic acid and monitored subsequently employing time-resolved Wilhelmy plate and Kelvin probe measurements. The isothermal state diagrams of the monolayers for both lateral pressure and surface potential are experimentally recorded, enabling us to predict dynamic voltage pulse amplitudes of 0.1-3 mV based on the assumption of static mechanoelectrical coupling. We show that the underlying physics for such propagating pulses is the same for synthetic and natural extracted (pork brain) lipids and that the measured propagation velocities and pulse amplitudes depend on the compressibility of the interface. Given the ubiquitous presence of hydrated interfaces in biology, our experimental findings seem to support a fundamentally new mechanism for the propagation of signals and communication pathways in biology (signaling), which is based neither on protein-protein or receptor-ligand interaction nor diffusion.
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Affiliation(s)
- J Griesbauer
- University of Augsburg, Experimental Physics I, D-86159 Augsburg, Germany and Boston University, Dept. of Mechanical Engineering, Boston, Massachusetts, USA
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17
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Reyes LF, Nobre TM, Pavinatto FJ, Zaniquelli ME, Caseli L, Oliveira ON, Araújo APU. The role of the C-terminal region of pulchellin A-chain in the interaction with membrane model systems. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:82-9. [DOI: 10.1016/j.bbamem.2011.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 09/29/2011] [Accepted: 10/04/2011] [Indexed: 02/02/2023]
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18
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Henriques VB, Germano R, Lamy MT, Tamashiro MN. Phase transitions and spatially ordered counterion association in ionic-lipid membranes: theory versus experiment. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:13130-13143. [PMID: 21848301 DOI: 10.1021/la202302x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Aqueous dispersions of phosphatidylglycerol (PG) lipids may present an anomalous chain-melting transition at low ionic strengths, as seen by different experimental techniques such as calorimetry or light scattering. The anomaly disappears at high ionic strengths or for longer acyl-chain lengths. In this article, we use a statistical model for the bilayer that distinguishes both lipid chain and headgroup states in order to compare model and experimental thermotropic and electrical properties. The effective van der Waals interactions among hydrophobic chains compete with the electrostatic repulsions between polar headgroups, which may be ionized (counterion dissociated) or electrically neutral (associated with counterions). Electric degrees of freedom introduce new thermotropic charge-ordered phases in which headgroup charges may be spatially ordered, depending on the electrolyte ionic strength, introducing a new rationale for experimental data on PGs. The thermal phases presented by the model for different chain lengths, at fixed ionic strength, compare well with an experimental phase diagram constructed on the basis of differential scanning calorimetry profiles. In the case of dispersions of DMPG (dimyristoyl phosphatidylglycerol) with added monovalent salt, the model properties reproduce the main features displayed by data from differential scanning calorimetry as well as the characteristic profile for the degree of ionization of the bilayer surface across the anomalous transition region, obtained from the theoretical interpretation of electrokinetic (conductivity and electrophoretic mobility) measurements.
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Affiliation(s)
- V B Henriques
- Instituto de Física, Universidade de São Paulo, Caixa Postal 66318, 05314-970 São Paulo, SP, Brazil.
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19
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Krajewska B, Wydro P, Jańczyk A. Probing the Modes of Antibacterial Activity of Chitosan. Effects of pH and Molecular Weight on Chitosan Interactions with Membrane Lipids in Langmuir Films. Biomacromolecules 2011; 12:4144-52. [DOI: 10.1021/bm2012295] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Barbara Krajewska
- Faculty of Chemistry, Jagiellonian University, 30-060 Kraków, Ingardena 3, Poland
| | - Paweł Wydro
- Faculty of Chemistry, Jagiellonian University, 30-060 Kraków, Ingardena 3, Poland
| | - Agnieszka Jańczyk
- Faculty of Chemistry, Jagiellonian University, 30-060 Kraków, Ingardena 3, Poland
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20
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Wilke N, Maggio B. Electrostatic field effects on membrane domain segregation and on lateral diffusion. Biophys Rev 2011; 3:185-192. [PMID: 28510045 DOI: 10.1007/s12551-011-0057-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 08/20/2011] [Indexed: 12/17/2022] Open
Abstract
Natural membranes are organized structures of neutral and charged molecules bearing dipole moments which generate local non-homogeneous electric fields. When subjected to such fields, the molecules experience net forces that can modify the lipid and protein organization, thus modulating cell activities and influencing (or even dominating) the biological functions. The energetics of electrostatic interactions in membranes is a long-range effect which can vary over distance within r-1 to r-3. In the case of a dipole interacting with a plane of dipoles, e.g. a protein interacting with a lipid domain, the interaction is stronger than two punctual dipoles and depends on the size of the domain. In this article, we review several contributions on how electrostatic interactions in the membrane plane can modulate the phase behavior, surface topography and mechanical properties in monolayers and bilayers.
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Affiliation(s)
- Natalia Wilke
- Centro de Investigaciones de Química Bológica de Córdoba (CIQUIBIC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina. .,CIQUIBIC, Dpto. de Química Biológica, Fac. de Cs. Químicas, UNC, Pabellón Argentina, Ciudad Universitaria, X5000HUA, Córdoba, Argentina.
| | - Bruno Maggio
- Centro de Investigaciones de Química Bológica de Córdoba (CIQUIBIC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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21
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Onai T, Hirai M. Morphology transition of raft-model membrane induced by osmotic pressure: Formation of double-layered vesicle similar to an endo- and/or exocytosis. ACTA ACUST UNITED AC 2010. [DOI: 10.1088/1742-6596/247/1/012018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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22
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Schwieger C, Blume A. Interaction of poly(L-arginine) with negatively charged DPPG membranes: calorimetric and monolayer studies. Biomacromolecules 2009; 10:2152-61. [PMID: 19603784 DOI: 10.1021/bm9003207] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The interaction of poly(L-arginine) (PLA) with dipalmitoyl-phosphatidylglycerol (DPPG) bilayer membranes and monolayers was studied by differential scanning calorimetry (DSC), isothermal titration calorimetry (ITC), and monolayer experiments. The binding of PLA affected the main transition temperature of lipid bilayers (T(m)) only marginally. Depending on the PLA chain length, T(m) was slightly increased or decreased. This finding was attributed to the superposition of two counteracting effects on the transition after PLA binding. The main transition enthalpy (DeltaH(m)) was decreased upon PLA binding and the formation of a ripple phase (P(beta)') was suppressed. ITC experiments showed that two distinct processes are involved in binding of PLA to gel phase (L(beta)') membranes. At low peptide content the binding reaction is endothermic, and at high peptide concentration the binding becomes exothermic. However, the enthalpy of binding to fluid (L(alpha)) membranes was exothermic for all peptide-to-lipid ratios. The temperature dependence of PLA binding to fluid palmitoyl-oleoyl-phosphatidylglycerol (POPG) membranes showed a decrease in binding enthalpy with increasing temperature (Delta(R)C(p) < 0), indicating hydrophobic contributions to the free energy of binding. For longer PLA chains, the binding enthalpy for L(alpha) membranes was more exothermic than for shorter chains. Monolayer adsorption experiments showed two consecutive binding processes. At low initial surface pressures (pi(0)) a condensation of the lipid film (Deltapi < 0) is first observed after PLA injection into the subphase, followed by an increase in film pressure (Deltapi > 0) due to insertion of peptide side chains into the monolayer. At higher pi(0) only an increase in film pressure can be observed due to the insertion of the side chains. Deltapi increases with increasing pi(0). The insertion of the peptide into the monolayer is corroborated by the observed shift of pi-A isotherms to higher molecular areas. All presented experiments show that the binding of PLA to DPPG membranes has not only electrostatic but also nonelectrostatic contributions.
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Affiliation(s)
- Christian Schwieger
- Martin-Luther-Universitat Halle-Wittenberg, Institute of Chemistry-Physical Chemistry, Muhlpforte 1, 06108 Halle, Germany
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23
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Nakahara H, Lee S, Shibata O. Pulmonary surfactant model systems catch the specific interaction of an amphiphilic peptide with anionic phospholipid. Biophys J 2009; 96:1415-29. [PMID: 19217859 DOI: 10.1016/j.bpj.2008.11.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Accepted: 11/20/2008] [Indexed: 10/21/2022] Open
Abstract
Interfacial behavior was studied in pulmonary surfactant model systems containing an amphiphilic alpha-helical peptide (Hel 13-5), which consists of 13 hydrophobic and five hydrophilic amino acid residues. Fully saturated phospholipids of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG) were utilized to understand specific interactions between anionic DPPG and cationic Hel 13-5 for pulmonary functions. Surface pressure (pi)-molecular area (A) and surface potential (DeltaV)-A isotherms of DPPG/Hel 13-5 and DPPC/DPPG (4:1, mol/mol)/Hel 13-5 preparations were measured to obtain basic information on the phase behavior under compression and expansion processes. The interaction leads to a variation in squeeze-out surface pressures against a mole fraction of Hel 13-5, where Hel 13-5 is eliminated from the surface on compression. The phase behavior was visualized by means of Brewster angle microscopy, fluorescence microscopy, and atomic force microscopy. At low surface pressures, the formation of differently ordered domains in size and shape is induced by electrostatic interactions. The domains independently grow upon compression to high surface pressures, especially in the DPPG/Hel 13-5 system. Under the further compression process, protrusion masses are formed in AFM images in the vicinity of squeeze-out pressures. The protrusion masses, which are attributed to the squeezed-out Hel 13-5, grow larger in lateral size with increasing DPPG content in phospholipid compositions. During subsequent expansion up to 35 mN m(-1), the protrusions retain their height and lateral diameter for the DPPG/Hel 13-5 system, whereas the protrusions become smaller for the DPPC/Hel 13-5 and DPPC/DPPG/Hel 13-5 systems due to a reentrance of the ejected Hel 13-5 into the surface. In this work we detected for the first time, to our knowledge, a remarkably large hysteresis loop for cyclic DeltaV-A isotherms of the binary DPPG/Hel 13-5 preparation. This exciting phenomenon suggests that the specific interaction triggers two completely independent processes for Hel 13-5 during repeated compression and expansion: 1), squeezing-out into the subsolution; and 2), and close packing as a monolayer with DPPG at the interface. These characteristic processes are also strongly supported by atomic force microscopy observations. The data presented here provide complementary information on the mechanism and importance of the specific interaction between the phosphatidylglycerol headgroup and the polarized moiety of native surfactant protein B for biophysical functions of pulmonary surfactants.
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Affiliation(s)
- Hiromichi Nakahara
- Department of Biophysical Chemistry, Faculty of Pharmaceutical Sciences, Nagasaki International University, Nagasaki, Japan
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24
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Giner Casares JJ, Camacho L, Martín-Romero MT, López Cascales JJ. Effect of Na+and Ca2+Ions on a Lipid Langmuir Monolayer: An Atomistic Description by Molecular Dynamics Simulations. Chemphyschem 2008; 9:2538-43. [DOI: 10.1002/cphc.200800321] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Garidel P, Johann C, Blume A. Thermodynamics of Lipid Organization and Domain Formation in Phospholipid Bilayers. J Liposome Res 2008. [DOI: 10.3109/08982100009029383] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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26
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27
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Lozano MM, Talu E, Longo ML. Dissolution of microbubbles generated in seawater obtained offshore: Behavior and surface tension measurements. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2007jc004108] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Onai T, Hirai M. Effect of osmotic pressure on ganglioside-cholesterol-DOPC lipid mixture. ACTA ACUST UNITED AC 2007. [DOI: 10.1088/1742-6596/83/1/012016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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29
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Aroti A, Leontidis E, Dubois M, Zemb T, Brezesinski G. Monolayers, bilayers and micelles of zwitterionic lipids as model systems for the study of specific anion effects. Colloids Surf A Physicochem Eng Asp 2007. [DOI: 10.1016/j.colsurfa.2007.03.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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30
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Maltseva E, Shapovalov VL, Möhwald H, Brezesinski G. Ionization state and structure of l-1,2-dipalmitoylphosphatidylglycerol monolayers at the liquid/air interface. J Phys Chem B 2006; 110:919-26. [PMID: 16471624 DOI: 10.1021/jp0555697] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phosphatidylglycerols are components of biological membranes. The phase behavior of these phospholipids was extensively investigated. However, there is still no definite picture about the dependence of the ionization state and monolayer structure on subphase composition. The major problem of previous investigations is that none of the methods used allow obtaining the ionization degree directly. In the present work we apply techniques developed in the past decades for Langmuir monolayers: infrared reflection absorption spectroscopy (IRRAS) as well as X-ray diffraction and reflectivity techniques, which provide straightforward information about structure and ionization state of a L-1,2-dipalmitoylphosphatidylglycerol (DPPG) monolayer. The Gouy-Chapman model is applied to evaluate the intrinsic pKa. Therewith, the ionization degree can be determined even at low pH values. The experimental titration curves are in good agreement with theoretical curves based on the Gouy-Chapman model. The obtained instrinic pKa amounts to 1. The ionization degree of a DPPG monolayer is independent of the monovalent cation size. In contrast, the structure of a DPPG monolayer is strongly affected by the type of divalent cations.
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Affiliation(s)
- Elena Maltseva
- Max Planck Institute of Colloids and Interfaces, 14476 Potsdam, Germany, and Institute of Chemical Physics, RAS, 117334 Moscow, Russia
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31
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Gopal A, Lee KYC. Headgroup Percolation and Collapse of Condensed Langmuir Monolayers. J Phys Chem B 2006; 110:22079-87. [PMID: 17078643 DOI: 10.1021/jp061562t] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present a study of Langmuir isotherms and 2D bulk moduli of binary lipid mixtures, where changes in monolayer collapse pressure (Pic) are followed while varying the relative amounts of the two components. For monolayers containing dipalmitoylphosphocholine (DPPC) with either hexadecanol (HD) or palmitic acid (PA), a distinctly non-monotonic change in Pic is observed with varying composition. At low mole fractions, there is a slight decrease in Pic as films get richer in DPPC, while a sharp increase to pure DPPC-like values is observed when the mole fraction exceeds approximately 0.7. The sudden transition in collapse pressure is explained using the principles of rigidity percolation, and important ramifications of this phenomenon for biological surfactant are discussed.
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Affiliation(s)
- Ajaykumar Gopal
- Department of Chemistry, the Institute for Biophysical Dynamics, and the James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA
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32
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Elmore DE. Molecular dynamics simulation of a phosphatidylglycerol membrane. FEBS Lett 2005; 580:144-8. [PMID: 16359668 DOI: 10.1016/j.febslet.2005.11.064] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Accepted: 11/25/2005] [Indexed: 11/19/2022]
Abstract
Although molecular dynamics simulations are an important tool for studying membrane systems, relatively few simulations have used anionic lipids. This paper reports the first simulation of a pure phosphatidylglycerol (PG) bilayer. The properties of this equilibrated palmitoyloleoylphosphatidylglycerol membrane agree with experimental observations of PG membranes and with previous simulations of monolayers and mixed bilayers containing PG lipids. These simulations also provide interesting insights into hydrogen bonding interactions in PG membranes. This equilibrated membrane will be a useful starting point for simulations of membrane proteins interacting with PG lipids.
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Affiliation(s)
- Donald E Elmore
- Department of Chemistry, Wellesley College, 106 Central St., Wellesley, MA 02481, USA.
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33
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Garidel P, Blume A. 1,2-Dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG) monolayers: influence of temperature, pH, ionic strength and binding of alkaline earth cations. Chem Phys Lipids 2005; 138:50-9. [PMID: 16219304 DOI: 10.1016/j.chemphyslip.2005.08.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Revised: 08/11/2005] [Accepted: 08/15/2005] [Indexed: 11/21/2022]
Abstract
Ion binding and lipid ionization of the acidic phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG) in monolayers was studied by measuring the lateral pressure Pi as a function of the molecular area A at the air/water interface at different temperatures. The pH of the subphase (pH 2 and 7) and the ionic strength (NaCl) was varied. In addition, different divalent cations (1mM MgCl2, CaCl2 and SrCl2, pH 7) were added. DMPG is partly protonated on pure water at pH 7. An increase in the NaCl concentration in the subphase leads to film expansion. This effect is caused by an ionization of the headgroup of DMPG, i.e. a shift of the apparent pK. More condensed films are obtained on pure water at pH 2, due to the reduction of electrostatic repulsion by headgroup protonation and the possibility for the formation of a hydrogen bonding network. The divalent cations Mg2+, Ca2+ and Sr2+ interact differently with a DMPG monolayer in pure water at pH 7. In the presence of 1mM CaCl2 a condensation of the DMPG film is induced, whereas an expansion of the monolayer is observed in the presence of Mg2+ and Sr2+. Two counteracting effects are operative: (a) ionization of the headgroup due to electrostatic screening leads to film expansion and (b) binding of the divalent cations to the lipid headgroups leads to condensation. The latter effect is more pronounced in the case of Ca2+, whereas the binding of Mg2+ and Sr2+ to DMPG is weaker. Site-specific cation binding has to be assumed in addition to electrostatic effects.
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Affiliation(s)
- Patrick Garidel
- Martin-Luther-University Halle/Wittenberg, Department of Chemistry Institute of Physical Chemistry, Mühlpforte 1, D-06108 Halle/Saale, Germany
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34
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Radoev B, Boev T, Avramov M. Electrostatics of heterogeneous monolayers. Constitutive equations and mathematical models. Adv Colloid Interface Sci 2005; 114-115:93-101. [PMID: 15936284 DOI: 10.1016/j.cis.2004.07.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Accepted: 07/12/2004] [Indexed: 11/21/2022]
Abstract
A new approach for modelling the electrochemistry of complex heterogeneous systems, composed of various bulk, surface and line phases, is proposed. A key step in it is the generalization of standard electrostatic boundary conditions, considered as 2D, 1D Poisson-Boltzmann equations. This viewpoint is applied to experimentally studied systems of two co-existing (e.g. liquid expanded, liquid condensed) monolayer phases. Another important feature of the given model is that, at electrochemical equilibrium, like with bulk double layers, surface double layers emerge on both sides of the contact line dividing the surface phases. A general mathematical formulation of the problem is proposed in respect of the electric potential as distributed in the complex heterogeneous system. Comments are also provided on the methods of solving the problem. The example illustrates a simplified system of two semi-infinite surface phases (monolayers) having equivalent parameters and divided by a contact line. The paper discusses the expressions obtained for the electrical potential, electrostatic energy, etc. and their dependence on the parameters of the system. Special focus is taken of the work of contact line formation.
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Affiliation(s)
- B Radoev
- Department of Physical Chemistry, Faculty of Chemistry, University of Sofia, 1 J. Baurchier Ave., 1164, Sofia, Bulgaria.
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35
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Berdysheva-Désert O, Desbat B, Saint-Pierre-Chazalet M. Competition of natural polyamines with dimethylsilyl analogues and monovalent cations in presence of a charged dipalmitoylphosphatidylglycerol monolayer. Colloids Surf B Biointerfaces 2005; 42:227-34. [PMID: 15893223 DOI: 10.1016/j.colsurfb.2005.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Revised: 01/05/2005] [Accepted: 02/07/2005] [Indexed: 11/20/2022]
Abstract
The interaction at the air/water interface of dipalmitoylphosphatidylglycerol (DPPG) with natural and dimethylsilyl polyamines are investigated first in the presence of NaCl in the subphase. Next, experiments are performed to study the competition between natural polyamines and dimethylsilyl analogues. The results obtained by surface pressure and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) with NaCl, are compared with those obtained with distilled water. A decrease of the DPPG mean molecular area is observed due to the local diminution of the Na+ concentration close to the polar head group and the simultaneous onset of interactions between the amino group of natural polyamines and the polar head group of DPPG. The same effects occur with azhepsi, followed by an insertion of the hydrophobic dimethylsilyl group. Near the polar head groups DPPG, a substitution of the Na+ by the amino groups of polyamines occurs. For the competition experiments, whereas a partial substitution is possible after putrescine and spermine adsorption, it is almost complete after spermine adsorption. Since the number of amino groups of azhepsi and spermine are the same, hydrophobic interactions due to the presence of dimethylsilyl group occur between azhepsi and the alkyl chains of DPPG. This favoured insertion of azhepsi provides a basis for understanding of the action of dimethylsilyl derivatives in the case of an antitumour strategy.
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Affiliation(s)
- Olga Berdysheva-Désert
- Laboratoire de Biophysique Moléculaire Cellulaire et Tissulaire, UMR CNRS 7033, Université Pierre et Marie Curie, case 138, 4 place Jussieu, F-75231 Paris Cedex 05, France
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36
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Velázquez MM, Ortega F, Monroy F, Rubio RG, Pegiadou S, Pérez L, Infante MR. Langmuir monolayers of the zwitterionic surfactant hexadecyl 1-N-l-tryptophan glycerol ether. J Colloid Interface Sci 2005; 283:144-52. [PMID: 15694435 DOI: 10.1016/j.jcis.2004.08.173] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Accepted: 08/11/2004] [Indexed: 10/26/2022]
Abstract
We report the formation of Langmuir monolayers of pure zwitterionic hexadecyl 1-N-L-tryptophan glycerol ether (C(16)-TGE) surfactant and mixed monolayers of cationic-zwitterionic surfactant obtained modifying the pH of the subphase. The pressure-area and surface potential-area isotherms and fluorescence microscopy measurements have been used to characterize the surface phase transitions in the monolayers. These transitions appeared at larger areas as the pH decreased from 6.0 to 2.0 and almost disappeared as the pH decreased further. The analysis of the surface potential and the infrared reflection-absorption spectroscopy data suggests that the phase transition is associated with a change of orientation of both the hydrocarbon chain and the aromatic group of the surfactant with respect to the air-water surface. The surface rheology of the monolayers was studied by quasielastic light scattering and by the oscillatory barrier technique. The results indicate that there is at least one relaxation process in the monolayer.
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Affiliation(s)
- M Mercedes Velázquez
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad de Salamanca, 37008 Salamanca, Spain.
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37
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Ivanov T, Radoev B. Role of the surface polarization on the nucleation of Langmuir monolayers. Colloids Surf A Physicochem Eng Asp 2004. [DOI: 10.1016/j.colsurfa.2004.06.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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38
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Aroti A, Leontidis E, Maltseva E, Brezesinski G. Effects of Hofmeister Anions on DPPC Langmuir Monolayers at the Air−Water Interface. J Phys Chem B 2004. [DOI: 10.1021/jp0481512] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Aroti
- Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus and Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany
| | - E. Leontidis
- Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus and Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany
| | - E. Maltseva
- Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus and Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany
| | - G. Brezesinski
- Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus and Max Planck Institute of Colloids and Interfaces, Potsdam 14424, Germany
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39
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Grigoriev D, Miller R, Wüstneck R, Wüstneck N, Pison U, Möhwald H. A Novel Method To Evaluate the Phase Transition Thermodynamics of Langmuir Monolayers. Application to DPPG Monolayers Affected by Subphase Composition. J Phys Chem B 2003. [DOI: 10.1021/jp0308662] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D. Grigoriev
- Max-Planck Institut für Kolloid- und Grenzflächenforschung, D-14424 Potsdam, Germany, St.-Petersburg State University, Institute of Chemistry, Universitetskiy pr. 2, St.-Petersburg, 198904 Russia, Sodtkestrasse 20, 10409 Berlin, Germany, and Humboldt University, Virchow Klinikum, Augustenburger Pl. 1, D-13344 Berlin, Germany
| | - R. Miller
- Max-Planck Institut für Kolloid- und Grenzflächenforschung, D-14424 Potsdam, Germany, St.-Petersburg State University, Institute of Chemistry, Universitetskiy pr. 2, St.-Petersburg, 198904 Russia, Sodtkestrasse 20, 10409 Berlin, Germany, and Humboldt University, Virchow Klinikum, Augustenburger Pl. 1, D-13344 Berlin, Germany
| | - R. Wüstneck
- Max-Planck Institut für Kolloid- und Grenzflächenforschung, D-14424 Potsdam, Germany, St.-Petersburg State University, Institute of Chemistry, Universitetskiy pr. 2, St.-Petersburg, 198904 Russia, Sodtkestrasse 20, 10409 Berlin, Germany, and Humboldt University, Virchow Klinikum, Augustenburger Pl. 1, D-13344 Berlin, Germany
| | - N. Wüstneck
- Max-Planck Institut für Kolloid- und Grenzflächenforschung, D-14424 Potsdam, Germany, St.-Petersburg State University, Institute of Chemistry, Universitetskiy pr. 2, St.-Petersburg, 198904 Russia, Sodtkestrasse 20, 10409 Berlin, Germany, and Humboldt University, Virchow Klinikum, Augustenburger Pl. 1, D-13344 Berlin, Germany
| | - U. Pison
- Max-Planck Institut für Kolloid- und Grenzflächenforschung, D-14424 Potsdam, Germany, St.-Petersburg State University, Institute of Chemistry, Universitetskiy pr. 2, St.-Petersburg, 198904 Russia, Sodtkestrasse 20, 10409 Berlin, Germany, and Humboldt University, Virchow Klinikum, Augustenburger Pl. 1, D-13344 Berlin, Germany
| | - H. Möhwald
- Max-Planck Institut für Kolloid- und Grenzflächenforschung, D-14424 Potsdam, Germany, St.-Petersburg State University, Institute of Chemistry, Universitetskiy pr. 2, St.-Petersburg, 198904 Russia, Sodtkestrasse 20, 10409 Berlin, Germany, and Humboldt University, Virchow Klinikum, Augustenburger Pl. 1, D-13344 Berlin, Germany
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40
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Petkova V, Platikanov D, Nedyalkov M. Phospholipid black foam films: dynamic contact angles and gas permeability of DMPC+DMPG black films. Adv Colloid Interface Sci 2003; 104:37-51. [PMID: 12818489 DOI: 10.1016/s0001-8686(03)00035-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The behavior of black foam films from aqueous dispersions of dimyristoylphosphatidyl-choline (DMPC) with addition of the soluble phospholipid dimyristoylphosphatidylglycerol (DMPG) has been studied in dynamic conditions. The dynamic contact angles theta and the gas permeability coefficient K have been measured using the diminishing bubble method. The DMPC vesicle suspension in water is obtained through sonication and DMPG is dissolved in it. Two solutions with different NaCl concentrations (0.1 M and 0.5 M) have been studied. The behavior of the dynamic contact angles is very different for DMPC black films with, and without DMPG, respectively. They follow very different time dependence during spontaneous or forced variations of the bubble size. The gas permeability coefficient is significantly reduced by the DMPG addition. The NaCl concentration also influences this specific behavior. It seems that the electrically charged DMPG anions, which determine a significant electrostatic disjoining pressure, play an important role for this specific behavior. The results are discussed in connection with data regarding the thickness and structure of these black foam films. Films from DMPC+DMPG solutions in ethanol plus water mixed solvent have been studied as well, but no quantitative results could be obtained.
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Affiliation(s)
- V Petkova
- Department of Physical Chemistry, University of Sofia, Boulevard James Bourchier 1, Sofia 1126, Bulgaria
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41
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Grigoriev DO, Krägel J, Akentiev AV, Noskov BA, Miller R, Pison U. Relation between rheological properties and structural changes in monolayers of model lung surfactant under compression. Biophys Chem 2003; 104:633-42. [PMID: 12914909 DOI: 10.1016/s0301-4622(03)00124-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
rSP-C surfactant monolayers spread on a native physiological model substrate show two plateau regions in the pi/A-isotherm. The first corresponds to the main phase transition in the monolayer from a LE to a LC phase. Its course is non-horizontal because of the complex composition of the lung surfactant. The second plateau, which is much more pronounced, cannot be attributed to a change of the phase state. Brewster angle microscopy images taken in this region show a sharp apparent decrease of the aggregation degree from the LE to the LC state. This process can be considered as a change in the monolayer orientation relative to the direction of the propagated light. Such a change can be the result of monolayer folding and formation of a thicker layer, which is supported by results of rheological measurements. The dilatation elasticity obtained from oscillating barrier and longitudinal wave measurements reveals a pure elastic behaviour with a steep increase in the second plateau region. Because of the insolubility of the pure lipid components, a possible explanation is squeezing protein components of rSP-C or its complexes with lipids out of the monolayer into the bulk.
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Affiliation(s)
- D O Grigoriev
- Max-Planck Institut für Kolloid-und Grenzflächenforschung, 14424 Potsdam, Germany.
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42
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Abstract
Results of atomistic molecular dynamics simulations of dipalmitoylphosphatidylcholine and dipalmitoylphosphatidylglycerol monolayers at the air/water interface are presented. Dipalmitoylphosphatidylcholine is zwitterionic and dipalmitoylphosphatidylglycerol is anionic at physiological pH. NaCl and CaCl2 water subphases are simulated. The simulations are carried out at different surface densities, and a simulation cell geometry is chosen that greatly facilitates the investigation of phospholipid monolayer properties. Ensemble average monolayer properties calculated from simulation are in agreement with experimental measurements. The dependence of the properties of the monolayers on the surface density, the type of the headgroup, and the ionic environment are explained in terms of atomistically detailed pair distribution functions and electron density profiles, demonstrating the strength of simulations in investigating complex, multicomponent systems of biological importance.
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Affiliation(s)
- Yiannis N Kaznessis
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136, USA
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43
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Ivanova A, Tadjer A, Radoev B, Panayotov I. A theoretical study of model lipid monolayers. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2002; 13:237-241. [PMID: 12071652 DOI: 10.1080/10629360290002730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Studies of pure phospholipid monolayers or various well defined lipid mixtures have greatly contributed to the current knowledge of the relationship between monolayer composition and its properties and to understand how their physicochemical properties, e.g. refraction, polarization, are controlled by structural variations at the molecular level. Therefore, an attempt was made to investigate model lipid molecules adsorbed on the air/water interface. Semi-empirical (AM1) quantum chemical calculations were performed for several clusters and were compared with experimental data. The optimized acidic molecules show a marked tendency to group forming domains. An increase in the number of surfactant molecules in the cluster leads to a decrease in the effective headgroup area. On the other hand, the area grows with the increase of the degree of ionization. Both relations are in accordance with the experimental trends and the electrostatic theory. The employed theoretical approach proves to be applicable to the study of monolayers, thus providing a reliable description at molecular level of the traditionally phenomenological investigations in the field.
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Affiliation(s)
- A Ivanova
- Department of Physical Chemistry, University of Sofia, Bulgaria.
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44
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Lohner K, Latal A, Degovics G, Garidel P. Packing characteristics of a model system mimicking cytoplasmic bacterial membranes. Chem Phys Lipids 2001; 111:177-92. [PMID: 11457444 DOI: 10.1016/s0009-3084(01)00157-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The phase diagram of fully hydrated mixtures of dipalmitoylphosphatidylethanolamine and -phosphatidylglycerol was constructed and the coexistence lines of the solidus and liquidus curve calculated based on regular solution theory using two nonideality parameters for each of the phase to account for nonideal and nonsymmetric mixing. Both lipids show nonideal miscibility in the liquid-crystalline phase, while a region of immiscibility exists in the lamellar-gel phase between the mole fraction x(DPPE)=0.05-0.4. Two lines of three-phase coexistence around 35 and 40 degrees C reflects the presence of lipid domains predominantly composed of phosphatidylglycerol as well as of the mixed lipid system. This is reflected in the positive nonideality parameters of the gel phase obtained from the simulation of the phase diagram. Moreover, segregation of pure phosphatidylethanolamine domains was detected in mixtures x(DPPE)>0.9, which formed multilamellar liposomes, while unilamellarity was observed for the mixed lipid systems owing to the presence of the negatively charged phosphatidylglycerol. The packing constraints of these phospholipids, major components of cytoplasmic bacterial membranes, may be of importance in the interaction with various solutes like antimicrobial peptides, and were explained based on the nature of the headgroups and the molecular geometry of the phospholipids.
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Affiliation(s)
- K Lohner
- Institut für Biophysik und Röntgenstrukturforschung, Osterreichische Akademie der Wissenschaften, Schmiedlstrasse 6, A-8042, Graz, Austria.
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45
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Effect of the surface polarization on the nucleation at liquid/gas interfaces. Colloids Surf A Physicochem Eng Asp 2000. [DOI: 10.1016/s0927-7757(00)00465-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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46
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J. L.Toca-Herrera,, Krustev R, Müller HJ, Möhwald H. Effect of the Charged Lipid DMPG on the Thickness and Contact Angle of Foam Films. J Phys Chem B 2000. [DOI: 10.1021/jp993098g] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. L.Toca-Herrera,
- Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, D-14476 Golm, Germany
| | - R. Krustev
- Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, D-14476 Golm, Germany
| | - H.-J. Müller
- Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, D-14476 Golm, Germany
| | - H. Möhwald
- Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, D-14476 Golm, Germany
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47
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Vollhardt D, Fainerman VB, Siegel S. Thermodynamic and Textural Characterization of DPPG Phospholipid Monolayers. J Phys Chem B 2000. [DOI: 10.1021/jp992529s] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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48
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Pencer J, Hallett FR. Small-angle neutron scattering from large unilamellar vesicles: an improved method for membrane thickness determination. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 2000; 61:3003-3008. [PMID: 11046629 DOI: 10.1103/physreve.61.3003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/1999] [Revised: 09/15/1999] [Indexed: 05/23/2023]
Abstract
Small-angle neutron scattering (SANS) measurements were performed on large unilamellar vesicles (LUVs) in order to investigate solute effects on membrane properties. Although SANS is a well established technique for the measurement of membrane thickness in unilamellar vesicles, earlier measurements have depended on approximate treatments of the scattering function and have suffered from effects of multilamellarity or difficulty in sample preparation. More recent studies of temperature induced thickness changes in DPPC LUVs which have included explicit treatment of the full scattering function were complicated by disparities between the predicted and measured scattering curves. Here, we reexamine theoretical descriptions of SANS from LUVs. Motivated by our observations, we then introduce a new method for interpretation of SANS data, which we compare to established techniques and apply to our measurements.
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Affiliation(s)
- J Pencer
- Department of Physics, University of Guelph, Ontario, Canada
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