1
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Prince A, Tiwari A, Mandal T, Koiri D, Meher G, Sinha DK, Saleem M. Lipid Specificity of the Fusion of Bacterial Extracellular Vesicles with the Host Membrane. J Phys Chem B 2024; 128:8116-8130. [PMID: 38981091 DOI: 10.1021/acs.jpcb.4c02321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Bacterial membrane vesicles (MVs) facilitate the long-distance delivery of virulence factors crucial for pathogenicity. The entry and trafficking mechanisms of virulence factors inside host cells are recently emerging; however, whether bacterial MVs can fuse and modulate the physicochemical properties of the host lipid membrane and membrane lipid parameter for fusion remains unknown. In this study, we reconstituted the interaction of bacterial MVs with host cell lipid membranes and quantitatively showed that bacterial MV interaction increases the fluidity, dipole potential, and compressibility of a biologically relevant multicomponent host membrane upon fusion. The presence of cylindrical lipids, such as phosphatidylcholine, and a moderate acyl chain length of C16 help the MV interaction. While significant binding of bacterial MVs to the raft-like lipid membranes with phase-separated regions of the membrane was observed, however, MVs prefer binding to the liquid-disordered regions of the membrane. Furthermore, the elevated levels of cholesterol tend to hinder the interaction of bacterial MVs, as evident from the favorable excess Gibbs free energy of mixing bacterial MVs with host lipid membranes. The findings provide new insights that might have implications for the regulation of host machinery by bacterial pathogens through manipulation of the host membrane properties.
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Affiliation(s)
- Ashutosh Prince
- Department of Life Sciences, National Institute of Technology, Rourkela 769008, India
| | - Anuj Tiwari
- Department of Life Sciences, National Institute of Technology, Rourkela 769008, India
| | - Titas Mandal
- Department of Physical Biochemistry, University of Potsdam, Potsdam 14476, Germany
| | - Debraj Koiri
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India
- Homi Bhabha National Institute, Mumbai 400094, India
| | - Geetanjali Meher
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India
- Homi Bhabha National Institute, Mumbai 400094, India
| | - Deepak Kumar Sinha
- Department of Biological Chemistry, Indian Association for the Cultivation of Sciences, Kolkata 700032, India
| | - Mohammed Saleem
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India
- Homi Bhabha National Institute, Mumbai 400094, India
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2
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Orlikowska-Rzeznik H, Versluis J, Bakker HJ, Piatkowski L. Cholesterol Changes Interfacial Water Alignment in Model Cell Membranes. J Am Chem Soc 2024; 146:13151-13162. [PMID: 38687869 PMCID: PMC11099968 DOI: 10.1021/jacs.4c00474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/20/2024] [Accepted: 04/22/2024] [Indexed: 05/02/2024]
Abstract
The nanoscopic layer of water that directly hydrates biological membranes plays a critical role in maintaining the cell structure, regulating biochemical processes, and managing intermolecular interactions at the membrane interface. Therefore, comprehending the membrane structure, including its hydration, is essential for understanding the chemistry of life. While cholesterol is a fundamental lipid molecule in mammalian cells, influencing both the structure and dynamics of cell membranes, its impact on the structure of interfacial water has remained unknown. We used surface-specific vibrational sum-frequency generation spectroscopy to study the effect of cholesterol on the structure and hydration of monolayers of the lipids 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), and egg sphingomyelin (SM). We found that for the unsaturated lipid DOPC, cholesterol intercalates in the membrane without significantly changing the orientation of the lipid tails and the orientation of the water molecules hydrating the headgroups of DOPC. In contrast, for the saturated lipids DPPC and SM, the addition of cholesterol leads to clearly enhanced packing and ordering of the hydrophobic tails. It is also observed that the orientation of the water hydrating the lipid headgroups is enhanced upon the addition of cholesterol. These results are important because the orientation of interfacial water molecules influences the cell membranes' dipole potential and the strength and specificity of interactions between cell membranes and peripheral proteins and other biomolecules. The lipid nature-dependent role of cholesterol in altering the arrangement of interfacial water molecules offers a fresh perspective on domain-selective cellular processes, such as protein binding.
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Affiliation(s)
- Hanna Orlikowska-Rzeznik
- Faculty
of Materials Engineering and Technical Physics, Poznan University of Technology, 60-965 Poznan, Poland
| | - Jan Versluis
- AMOLF,
Ultrafast Spectroscopy, 1098 XG Amsterdam, The Netherlands
| | - Huib J. Bakker
- AMOLF,
Ultrafast Spectroscopy, 1098 XG Amsterdam, The Netherlands
| | - Lukasz Piatkowski
- Faculty
of Materials Engineering and Technical Physics, Poznan University of Technology, 60-965 Poznan, Poland
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3
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Jawaharlal S, Subramanian S, Palanivel V, Devarajan G, Veerasamy V. Cyclodextrin-based nanosponges as promising carriers for active pharmaceutical ingredient. J Biochem Mol Toxicol 2024; 38:e23597. [PMID: 38037252 DOI: 10.1002/jbt.23597] [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: 02/09/2023] [Revised: 10/18/2023] [Accepted: 11/20/2023] [Indexed: 12/02/2023]
Abstract
Effective drug distribution at the intended or particular location is a critical issue that researchers are now dealing. Nanosponges have significantly increased in importance in medication delivery using nanotechnology in recent years. An important step toward solving these problems has been the development of nanosponges. Recently created and proposed for use in drug delivery, nanosponge is a unique type of hyper-crosslinked polymer-based colloidal structures made up of solid nanoparticles with colloidal carriers. Nanosponges are solid porous particles that may hold pharmaceuticals and other actives in their nanocavities. They can be made into dosage forms for oral, parenteral, topical, or inhalation use. The targeted distribution of drugs in a regulated manner is greatly aided by nanosponge. The utilization of nanosponges, their benefits, their production processes, the polymers they are made of, and their characterization have all been covered in this review article.
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Affiliation(s)
- Saranya Jawaharlal
- Department of Biochemistry & Biotechnology, Annamalai University, Annamalai Nagar, Tamil Nadu, India
| | | | - Venkatesan Palanivel
- Department of Pharmacy, Annamalai University, Annamalai Nagar, Tamil Nadu, India
| | - Geetha Devarajan
- Department of Physics, Annamalai University, Annamalai Nagar, Tamil Nadu, India
| | - Vinothkumar Veerasamy
- Department of Biochemistry & Biotechnology, Annamalai University, Annamalai Nagar, Tamil Nadu, India
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4
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Soltész D, Szabó I, Bánóczi Z. The Balance between Hydrophobicity/Aromaticity and Positively Charged Residues May Influence the Cell Penetration Ability. Pharmaceutics 2023; 15:pharmaceutics15041267. [PMID: 37111751 PMCID: PMC10146604 DOI: 10.3390/pharmaceutics15041267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/05/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Cell-penetrating peptides (CPPs) are commonly modified to increase their cellular uptake, alter the mechanism of penetration or enhance their endosomal release. Earlier, we described the internalization enhancement ability of the 4-((4-(dimethylamino)phenyl)azo)benzoyl (Dabcyl) group. We proved that this modification on the N-terminus of tetra- and hexaarginine enhanced their cellular uptake. The introduction of an aromatic ring 4-(aminomethyl) benzoic acid, AMBA) into the peptide backbone has a synergistic effect with Dabcyl, and the tetraarginine derivatives had outstanding cellular uptake. Based on these results, the effect of Dabcyl or Dabcyl-AMBA modification on the internalization of oligoarginines was studied. Oligoarginines were modified with these groups and their internalization was measured using flow cytometry. The concentration dependence of the cellular uptake of selected constructs was compared too. Their internalization mechanism was also examined by using different endocytosis inhibitors. While the effect of the Dabcyl group was optimal for hexaarginine, the Dabcyl-AMBA group increased the cellular uptake in the case of all oligoarginines. All derivatives, with the exception of only tetraarginine, were more effective than the octaarginine control. The internalization mechanism was dependent on the size of the oligoarginine and was independent of the modification. Our findings suggest that these modifications enhanced the internalization of oligoarginines and resulted in novel, very effective CPPs.
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Affiliation(s)
- Dóra Soltész
- Department of Organic Chemistry, Eötvös L. University, 1117 Budapest, Hungary
| | - Ildikó Szabó
- ELKH-ELTE Research Group of Peptide Chemistry, 1117 Budapest, Hungary
| | - Zoltán Bánóczi
- Department of Organic Chemistry, Eötvös L. University, 1117 Budapest, Hungary
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5
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Colmano N, Sánchez-Borzone ME, Turina AV. Effects of Fipronil and surface behavior of neuronal insect and mammalian membranes. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183979. [PMID: 35654149 DOI: 10.1016/j.bbamem.2022.183979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 04/25/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Nicolás Colmano
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Química, Cátedra de Química Biológica, Córdoba, Argentina; Instituto de Investigaciones Biológicas y Tecnológicas, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Mariela E Sánchez-Borzone
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Química, Cátedra de Química Biológica, Córdoba, Argentina; Instituto de Investigaciones Biológicas y Tecnológicas, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Anahí V Turina
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Química, Cátedra de Química Biológica, Córdoba, Argentina; Instituto de Investigaciones Biológicas y Tecnológicas, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
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6
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Sarkar P, Chattopadhyay A. Membrane Dipole Potential: An Emerging Approach to Explore Membrane Organization and Function. J Phys Chem B 2022; 126:4415-4430. [PMID: 35696090 DOI: 10.1021/acs.jpcb.2c02476] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Biological membranes are complex organized molecular assemblies of lipids and proteins that provide cells and membrane-bound intracellular organelles their individual identities by morphological compartmentalization. Membrane dipole potential originates from the electrostatic potential difference within the membrane due to the nonrandom arrangement (orientation) of amphiphile and solvent (water) dipoles at the membrane interface. In this Feature Article, we will focus on the measurement of dipole potential using electrochromic fluorescent probes and highlight interesting applications. In addition, we will focus on ratiometric fluorescence microscopic imaging technique to measure dipole potential in cellular membranes, a technique that can be used to address novel problems in cell biology which are otherwise difficult to address using available approaches. We envision that membrane dipole potential could turn out to be a convenient tool in exploring the complex interplay between membrane lipids and proteins and could provide novel insights in membrane organization and function.
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Affiliation(s)
- Parijat Sarkar
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
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7
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Nguyen HL, Man VH, Li MS, Derreumaux P, Wang J, Nguyen PH. Elastic moduli of normal and cancer cell membranes revealed by molecular dynamics simulations. Phys Chem Chem Phys 2022; 24:6225-6237. [PMID: 35229839 DOI: 10.1039/d1cp04836h] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Recent studies indicate that there are mechanical differences between normal cells and cancer cells. Because the cell membrane takes part in a variety of vital processes, we test the hypothesis of whether or not two fundamental alterations in the cell membrane, i.e., the overexpression of phosphatidylserine lipids in the outer leaflet and a reduction in cholesterol concentration, could cause the softening in cancer cells. Adopting ten models of normal and cancer cell membranes, we carry out 1 μs all-atom molecular dynamics simulations to compare the structural properties and elasticity properties of two membrane types. We find that the overexpression of the phosphatidylserine lipids in the outer leaflet does not significantly alter the area per lipid, the membrane thickness, the lipid order parameters and the elasticity moduli of the cancer membranes. However, a reduction in the cholesterol concentration leads to clear changes in those quantities, especially decreases in the bending, tilt and twist moduli. This implies that the reduction of cholesterol concentration in the cancer membranes could contribute to the softening of cancer cells.
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Affiliation(s)
- Hoang Linh Nguyen
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam
| | - Viet Hoang Man
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Mai Suan Li
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City, Vietnam.,Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Philippe Derreumaux
- CNRS, Université de Paris, UPR9080, Laboratoire de Biochimie Théorique, Paris, France
| | - Junmei Wang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Phuong H Nguyen
- CNRS, Université de Paris, UPR9080, Laboratoire de Biochimie Théorique, Paris, France.,Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild, PSL Research University, Paris, France.
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8
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Zakany F, Szabo M, Batta G, Kárpáti L, Mándity IM, Fülöp P, Varga Z, Panyi G, Nagy P, Kovacs T. An ω-3, but Not an ω-6 Polyunsaturated Fatty Acid Decreases Membrane Dipole Potential and Stimulates Endo-Lysosomal Escape of Penetratin. Front Cell Dev Biol 2021; 9:647300. [PMID: 33912562 PMCID: PMC8074792 DOI: 10.3389/fcell.2021.647300] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 03/22/2021] [Indexed: 12/21/2022] Open
Abstract
Although the largely positive intramembrane dipole potential (DP) may substantially influence the function of transmembrane proteins, its investigation is deeply hampered by the lack of measurement techniques suitable for high-throughput examination of living cells. Here, we describe a novel emission ratiometric flow cytometry method based on F66, a 3-hydroxiflavon derivative, and demonstrate that 6-ketocholestanol, cholesterol and 7-dehydrocholesterol, saturated stearic acid (SA) and ω-6 γ-linolenic acid (GLA) increase, while ω-3 α-linolenic acid (ALA) decreases the DP. These changes do not correlate with alterations in cell viability or membrane fluidity. Pretreatment with ALA counteracts, while SA or GLA enhances cholesterol-induced DP elevations. Furthermore, ALA (but not SA or GLA) increases endo-lysosomal escape of penetratin, a cell-penetrating peptide. In summary, we have developed a novel method to measure DP in large quantities of individual living cells and propose ALA as a physiological DP lowering agent facilitating cytoplasmic entry of penetratin.
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Affiliation(s)
- Florina Zakany
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Mate Szabo
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gyula Batta
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Levente Kárpáti
- Department of Organic Chemistry, Faculty of Pharmacy, Semmelweis University, Budapest, Hungary
| | - István M. Mándity
- Department of Organic Chemistry, Faculty of Pharmacy, Semmelweis University, Budapest, Hungary
- Lendület-Artificial Chloride Ion Transporter Group, Institute of Materials and Environmental Chemistry, Research Center for Natural Sciences, Budapest, Hungary
| | - Péter Fülöp
- Division of Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltan Varga
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gyorgy Panyi
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Peter Nagy
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamas Kovacs
- Division of Biophysics, Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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9
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Batta G, Kárpáti L, Henrique GF, Tarapcsák S, Kovács T, Zákány F, Mándity IM, Nagy P. Statin-boosted cellular uptake of penetratin due to reduced membrane dipole potential.. [DOI: 10.1101/2020.08.04.236984] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
AbstractSince cell penetrating peptides are promising tools for delivery of cargo into cells, factors limiting or facilitating their cellular uptake are intensely studied. Using labeling with pH-insensitive and pH-sensitive dyes we report that escape of penetratin from acidic endo-lysosomal compartments is retarded compared to its cellular uptake. The membrane dipole potential, known to alter transmembrane transport of charged molecules, is shown to be negatively correlated with the concentration of penetratin in the cytoplasmic compartment. Treatment of cells with therapeutically relevant concentrations of atorvastatin, an inhibitor of HMG-CoA reductase and cholesterol synthesis, significantly increased the release of penetratin from acidic endocytic compartments in two different cell types. This effect of atorvastatin correlated with its ability to decrease the membrane dipole potential. These results highlight the importance of the dipole potential in regulating cellular uptake of cell penetrating peptides and suggest a clinically relevant way of boosting this process.
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10
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Direct and indirect cholesterol effects on membrane proteins with special focus on potassium channels. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158706. [DOI: 10.1016/j.bbalip.2020.158706] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 03/19/2020] [Accepted: 03/30/2020] [Indexed: 12/16/2022]
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11
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Effect of dipole moment on amphiphile solubility and partition into liquid ordered and liquid disordered phases in lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183157. [PMID: 31846646 DOI: 10.1016/j.bbamem.2019.183157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/01/2019] [Accepted: 12/12/2019] [Indexed: 12/20/2022]
Abstract
Association of amphiphiles with biomembranes is important for their availability at specific locations in organisms and cells, being critical for their biological function. A prominent role is usually attributed to the hydrophobic effect, and to electrostatic interactions between charged amphiphiles and lipids. This work explores a closely related and complementary aspect, namely the contribution made by dipole moments to the strength of the interactions established. Two xanthene amphiphiles with opposite relative orientations of their dipole and amphiphilic moments have been selected (Rhodamine-C14 and Carboxyfluorescein-C14). The membranes studied have distinct lipid compositions, representing typical cell membrane pools, ranging from internal membranes to the outer and inner leaflet of the plasma membrane. A comprehensive study is reported, including the affinity of the amphiphiles for the different membranes, the stability of the amphiphiles as monomers and their tendency to form small clusters, as well as their transverse location in the membrane. The orientation of the amphiphile dipole moment, which determines whether its interaction with the membrane dipole potential is repulsive or attractive, is found to exert a large influence on the association of the amphiphile with ordered lipid membranes. These interactions are also responsible for the formation of small clusters or stabilization of amphiphile monomers in the membrane. The results obtained allow understanding the prevalence of protein lipidation at the N-terminal for efficient targeting to the plasma membrane, as well as the tendency of GPI-anchored proteins (usually lipidated at the C-terminal) to form small clusters in the membrane ordered domains.
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12
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Andrews DL. Effects of Intrinsic Local Fields on Molecular Fluorescence and Energy Transfer: Dipole Mechanisms and Surface Potentials. J Phys Chem B 2019; 123:5015-5023. [PMID: 30908043 DOI: 10.1021/acs.jpcb.9b00212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A general theory is developed to identify the influence of local dipole fields on fluorescence and intermolecular electronic excitation transfer. The analysis, based on electrodynamical principles, identifies the fundamental quantum mechanisms and delivers full analytical results. The aim is to afford new physical insights, assisting the interpretation of measurements on the specific effects of local molecular dipoles on direct fluorescence and on fluorescence resonance energy transfer. Dipole field effects, which include those originating from intrinsically polar chromophores and surface field gradients, also prove to be manifest in electronic transitions of quadrupole symmetry character. The results have particular significance for fluorescence studies of cell membrane biophysics.
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Affiliation(s)
- David L Andrews
- School of Chemistry , University of East Anglia , Norwich Research Park , Norwich NR4 7TJ , U.K
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13
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Shahane G, Ding W, Palaiokostas M, Orsi M. Physical properties of model biological lipid bilayers: insights from all-atom molecular dynamics simulations. J Mol Model 2019; 25:76. [PMID: 30806797 DOI: 10.1007/s00894-019-3964-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 02/07/2019] [Indexed: 02/04/2023]
Abstract
The physical properties of lipid bilayers are sensitive to the specific type and composition of the lipids that make up the many different types of cell membranes. Studying model bilayers of representative heterogeneous compositions can provide key insights into membrane functionality. In this work, we use atomistic molecular dynamics simulations to characterize key properties in a number of bilayer membranes of varying composition. We first examine basic properties, such as lipid area, volume, and bilayer thickness, of simple, homogeneous bilayers comprising several lipid types, which are prevalent in biological membranes. Such lipids are then used in simulations of heterogeneous systems representative of bacterial, mammalian, and cancer membranes. Our analysis is especially focused on depth-dependent, transmembrane profiles; in particular, we calculate lateral pressure and dipole potential profiles, two fundamental properties which play key roles in a large number of biological functions.
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Affiliation(s)
- Ganesh Shahane
- Institute of Bioengineering, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Wei Ding
- School of Engineering & Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Michail Palaiokostas
- School of Engineering & Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Mario Orsi
- Department of Applied Sciences, University of the West of England, Coldharbour Lane, Bristol, BS16 1QY, UK.
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14
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Affiliation(s)
- Xiaolin Cheng
- Division of Medicinal Chemistry and Pharmacognosy, Biophysics Graduate Program, Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jeremy C. Smith
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6309, United States
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
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15
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Bokori-Brown M, Metz J, Petrov PG, Mussai F, De Santo C, Smart NJ, Saunders S, Knight B, Pastan I, Titball RW, Winlove CP. Interactions Between Pseudomonas Immunotoxins and the Plasma Membrane: Implications for CAT-8015 Immunotoxin Therapy. Front Oncol 2018; 8:553. [PMID: 30538953 PMCID: PMC6277520 DOI: 10.3389/fonc.2018.00553] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/08/2018] [Indexed: 11/13/2022] Open
Abstract
Acute Lymphoblastic Leukemia (ALL) remains the most frequent cause of cancer-related mortality in children and novel therapies are needed for the treatment of relapsed/refractory childhood ALL. One approach is the targeting of ALL blasts with the Pseudomonas immunotoxin CAT-8015. Although CAT-8015 has potent anti-leukemia activity, with a 32% objective response rate in a phase 1 study of childhood ALL, haemolytic-uremic syndrome (HUS) and vascular leak syndrome (VLS), major dose-limiting toxicities, have limited the use of this therapeutic approach in children. Investigations into the pathogenesis of CAT-8015-induced HUS/VLS are hindered by the lack of an adequate model system that replicates clinical manifestations, but damage to vascular endothelial cells (ECs) and blood cells are believed to be major initiating factors in both syndromes. Since there is little evidence that murine models replicate human HUS/VLS, and CAT-8015-induced HUS/VLS predominantly affects children, we developed human models and used novel methodologies to investigate CAT-8015 interactions with red blood cells (RBCs) from pediatric ALL patients and ECs of excised human mesenteric arteries. We provide evidence that CAT-8015 directly interacts with RBCs, mediated by Pseudomonas toxin. We also show correlation between the electrical properties of the RBC membrane and RBC susceptibility to CAT-8015-induced lysis, which may have clinical implication. Finally, we provide evidence that CAT-8015 is directly cytototoxic to ECs of excised human mesenteric arteries. In conclusion, the human models we developed constitutes the first, and very important, step in understanding the origins of HUS/VLS in immunotoxin therapy and will allow further investigations of HUS/VLS pathogenesis.
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Affiliation(s)
- Monika Bokori-Brown
- College of Life and Environmental Sciences, School of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Jeremy Metz
- College of Life and Environmental Sciences, School of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Peter G. Petrov
- College of Engineering, Mathematics and Physical Sciences, Department of Physics and Astronomy, University of Exeter, Exeter, United Kingdom
| | - Francis Mussai
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Carmela De Santo
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Neil J. Smart
- Exeter Surgical Health Services Research Unit, Royal Devon and Exeter Hospital, Exeter, United Kingdom
| | - Sarah Saunders
- Histopathology Department, Royal Devon and Exeter Hospital, Exeter, United Kingdom
| | - Bridget Knight
- National Institute for Health Research Exeter Clinical Research Facility, Royal Devon and Exeter National Health Service Foundation Trust, Exeter, United Kingdom
| | - Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, United States
| | - Richard W. Titball
- College of Life and Environmental Sciences, School of Biosciences, University of Exeter, Exeter, United Kingdom
| | - C. Peter Winlove
- College of Engineering, Mathematics and Physical Sciences, Department of Physics and Astronomy, University of Exeter, Exeter, United Kingdom
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16
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Shen H, Deng M, Wu Z, Zhang J, Zhang Y, Gao C, Cen C. Effect of Cholesterol on Membrane Dipole Potential: Atomistic and Coarse-Grained Molecular Dynamics Simulations. J Chem Theory Comput 2018; 14:3780-3795. [DOI: 10.1021/acs.jctc.8b00092] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Hujun Shen
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
- Guizhou University of Finance and Economics, School of Information, University City of Huaxi District, Guiyang, Guizhou 550025, P. R. China
| | - Mingsen Deng
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
- Guizhou University of Finance and Economics, School of Information, University City of Huaxi District, Guiyang, Guizhou 550025, P. R. China
| | - Zhenhua Wu
- Guizhou University of Finance and Economics, School of Information, University City of Huaxi District, Guiyang, Guizhou 550025, P. R. China
| | - Jihua Zhang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
| | - Yachao Zhang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
| | - Chengui Gao
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
| | - Cao Cen
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
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17
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Gomes B, Gonçalves S, Disalvo A, Hollmann A, Santos NC. Effect of 25-hydroxycholesterol in viral membrane fusion: Insights on HIV inhibition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1171-1178. [PMID: 29408450 DOI: 10.1016/j.bbamem.2018.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 01/08/2018] [Accepted: 02/01/2018] [Indexed: 12/15/2022]
Abstract
Recently, it was demonstrated that 25-hydroxycholesterol (25HC), an oxidized cholesterol derivative, inhibits human immunodeficiency virus type 1 (HIV) entry into its target cells. However, the mechanisms involved in this action have not yet been established. The aim of this work was to study the effects of 25HC in biomembrane model systems and at the level of HIV fusion peptide (HIV-FP). Integration of different biophysical approaches was made in the context of HIV fusion process, to clarify the changes at membrane level due to the presence of 25HC that result in the suppressing of viral infection. Lipid vesicles mimicking mammalian and HIV membranes were used on spectroscopy assays and lipid monolayers in surface pressure studies. Peptide-induced lipid mixing assays were performed by Förster resonance energy transfer to calculate fusion efficiency. Liposome fusion is reduced by 50% in the presence of 25HC, comparatively to cholesterol. HIV-FP conformation was assessed by infrared assays and it relies on sterol nature. Anisotropy, surface pressure and dipole potential assays indicate that the conversion of cholesterol in 25HC leads to a loss of the cholesterol modulating effect on the membrane. With different biophysical techniques, we show that 25HC affects the membrane fusion process through the modification of lipid membrane properties, and by direct alterations on HIV-FP structure. The present data support a broad antiviral activity for 25HC.
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Affiliation(s)
- Bárbara Gomes
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Sónia Gonçalves
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Anibal Disalvo
- Laboratory of Biointerfaces and Biomimetic Systems, CITSE, University of Santiago del Estero, -CONICET, 4200 Santiago del Estero, Argentina
| | - Axel Hollmann
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal; Laboratory of Biointerfaces and Biomimetic Systems, CITSE, University of Santiago del Estero, -CONICET, 4200 Santiago del Estero, Argentina; Laboratory of Molecular Microbiology, Institute of Basic and Applied Microbiology, University of Quilmes, B1876BXD Bernal, Argentina
| | - Nuno C Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal.
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18
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Davis BM, Brenton J, Davis S, Shamsher E, Sisa C, Grgic L, Cordeiro MF. Assessing anesthetic activity through modulation of the membrane dipole potential. J Lipid Res 2017; 58:1962-1976. [PMID: 28818873 PMCID: PMC5625120 DOI: 10.1194/jlr.m073932] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 08/09/2017] [Indexed: 12/21/2022] Open
Abstract
There is great individual variation in response to general anesthetics (GAs) leading to difficulties in optimal dosing and sometimes even accidental awareness during general anesthesia (AAGA). AAGA is a rare, but potentially devastating, complication affecting between 0.1% and 2% of patients undergoing surgery. The development of novel personalized screening techniques to accurately predict a patient’s response to GAs and the risk of AAGA remains an unmet clinical need. In the present study, we demonstrate the principle of using a fluorescent reporter of the membrane dipole potential, di-8-ANEPPs, as a novel method to monitor anesthetic activity using a well-described inducer/noninducer pair. The membrane dipole potential has previously been suggested to contribute a novel mechanism of anesthetic action. We show that the fluorescence ratio of di-8-ANEPPs changed in response to physiological concentrations of the anesthetic, 1-chloro-1,2,2-trifluorocyclobutane (F3), but not the structurally similar noninducer, 1,2-dichlorohexafluorocyclobutane (F6), to artificial membranes and in vitro retinal cell systems. Modulation of the membrane dipole provides an explanation to overcome the limitations associated with the alternative membrane-mediated mechanisms of GA action. Furthermore, by combining this technique with noninvasive retinal imaging technologies, we propose that this technique could provide a novel and noninvasive technique to monitor GA susceptibility and identify patients at risk of AAGA.
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Affiliation(s)
| | - Jonathan Brenton
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - Sterenn Davis
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - Ehtesham Shamsher
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - Claudia Sisa
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - Ljuban Grgic
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - M Francesca Cordeiro
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom .,Western Eye Hospital, Imperial College Healthcare National Health Service Trust, and Imperial College Ophthalmic Research Group, Imperial College London, London NW1 5QH, United Kingdom
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19
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Kovács T, Batta G, Zákány F, Szöllősi J, Nagy P. The dipole potential correlates with lipid raft markers in the plasma membrane of living cells. J Lipid Res 2017; 58:1681-1691. [PMID: 28607008 DOI: 10.1194/jlr.m077339] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/06/2017] [Indexed: 11/20/2022] Open
Abstract
The dipole potential generating an electric field much stronger than any other type of membrane potential influences a wide array of phenomena, ranging from passive permeation to voltage-dependent conformational changes of membrane proteins. It is generated by the ordered orientation of lipid carbonyl and membrane-attached water dipole moments. Theoretical considerations and indirect experimental evidence obtained in model membranes suggest that the dipole potential is larger in liquid-ordered domains believed to correspond to lipid rafts in cell membranes. Using three different dipole potential-sensitive fluorophores and four different labeling approaches of raft and nonraft domains, we showed that the dipole potential is indeed stronger in lipid rafts than in the rest of the membrane. The magnitude of this difference is similar to that observed between the dipole potential in control and sphingolipid-enriched cells characteristic of Gaucher's disease. The results established that the heterogeneity of the dipole potential in living cell membranes is correlated with lipid rafts and imply that alterations in the lipid composition of the cell membrane in human diseases can lead to substantial changes in the dipole potential.
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Affiliation(s)
- Tamás Kovács
- Department of Biophysics and Cell Biology Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Gyula Batta
- Faculty of Medicine, and Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Florina Zákány
- Department of Biophysics and Cell Biology Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - János Szöllősi
- Department of Biophysics and Cell Biology Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary; MTA-DE Cell Biology and Signaling Research Group, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Peter Nagy
- Department of Biophysics and Cell Biology Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.
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20
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Falkovich SG, Martinez-Seara H, Nesterenko AM, Vattulainen I, Gurtovenko AA. What Can We Learn about Cholesterol's Transmembrane Distribution Based on Cholesterol-Induced Changes in Membrane Dipole Potential? J Phys Chem Lett 2016; 7:4585-4590. [PMID: 27791378 DOI: 10.1021/acs.jpclett.6b02123] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Cholesterol is abundant in the plasma membranes of animal cells and is known to regulate a variety of membrane properties. Despite decades of research, the transmembrane distribution of cholesterol is still a matter of debate. Here we consider this outstanding issue through atomistic simulations of asymmetric lipid membranes, whose composition is largely consistent with eukaryotic plasma membranes. We show that the membrane dipole potential changes in a cholesterol-dependent manner. Remarkably, moving cholesterol from the extracellular to the cytosolic leaflet increases the dipole potential on the cytosolic side, and vice versa. Biologically this implies that by altering the dipole potential, cholesterol can provide a driving force for cholesterol molecules to favor the cytosolic leaflet, in order to compensate for the intramembrane field that arises from the resting potential.
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Affiliation(s)
- Stanislav G Falkovich
- Institute of Macromolecular Compounds, Russian Academy of Sciences , Bolshoi Prospect V.O. 31, St. Petersburg 199004, Russia
| | - Hector Martinez-Seara
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences , Flemingovo náměstí 542/2, 166 10 Praha 6, Czech Republic
- Department of Physics, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland
| | - Alexey M Nesterenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University , Leninskie Gory, 1/40, 119991 Moscow, Russia
| | - Ilpo Vattulainen
- Department of Physics, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland
- Department of Physics, University of Helsinki , P.O. Box 64, FI-00014 Helsinki, Finland
- MEMPHYS - Center for Biomembrane Physics, University of Southern Denmark , Odense, Denmark
| | - Andrey A Gurtovenko
- Institute of Macromolecular Compounds, Russian Academy of Sciences , Bolshoi Prospect V.O. 31, St. Petersburg 199004, Russia
- Faculty of Physics, St. Petersburg State University , Ulyanovskaya str. 3, Petrodvorets, St. Petersburg, 198504 Russia
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21
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Rokitskaya TI, Murphy MP, Skulachev VP, Antonenko YN. Ubiquinol and plastoquinol triphenylphosphonium conjugates can carry electrons through phospholipid membranes. Bioelectrochemistry 2016; 111:23-30. [DOI: 10.1016/j.bioelechem.2016.04.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/26/2016] [Accepted: 04/26/2016] [Indexed: 11/16/2022]
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22
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Bokori-Brown M, Petrov PG, Khafaji MA, Mughal MK, Naylor CE, Shore AC, Gooding KM, Casanova F, Mitchell TJ, Titball RW, Winlove CP. Red Blood Cell Susceptibility to Pneumolysin: CORRELATION WITH MEMBRANE BIOCHEMICAL AND PHYSICAL PROPERTIES. J Biol Chem 2016; 291:10210-27. [PMID: 26984406 DOI: 10.1074/jbc.m115.691899] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 12/20/2022] Open
Abstract
This study investigated the effect of the biochemical and biophysical properties of the plasma membrane as well as membrane morphology on the susceptibility of human red blood cells to the cholesterol-dependent cytolysin pneumolysin, a key virulence factor of Streptococcus pneumoniae, using single cell studies. We show a correlation between the physical properties of the membrane (bending rigidity and surface and dipole electrostatic potentials) and the susceptibility of red blood cells to pneumolysin-induced hemolysis. We demonstrate that biochemical modifications of the membrane induced by oxidative stress, lipid scrambling, and artificial cell aging modulate the cell response to the toxin. We provide evidence that the diversity of response to pneumolysin in diabetic red blood cells correlates with levels of glycated hemoglobin and that the mechanical properties of the red blood cell plasma membrane are altered in diabetes. Finally, we show that diabetic red blood cells are more resistant to pneumolysin and the related toxin perfringolysin O relative to healthy red blood cells. Taken together, these studies indicate that the diversity of cell response to pneumolysin within a population of human red blood cells is influenced by the biophysical and biochemical status of the plasma membrane and the chemical and/or oxidative stress pre-history of the cell.
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Affiliation(s)
- Monika Bokori-Brown
- From the College of Life and Environmental Sciences, School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom,
| | - Peter G Petrov
- the College of Engineering, Mathematics and Physical Sciences, School of Physics, University of Exeter, Exeter EX4 4QL, United Kingdom
| | - Mawya A Khafaji
- the College of Engineering, Mathematics and Physical Sciences, School of Physics, University of Exeter, Exeter EX4 4QL, United Kingdom
| | - Muhammad K Mughal
- the Institute of Microbiology and Infection, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Claire E Naylor
- the Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, United Kingdom
| | - Angela C Shore
- the Department of Diabetes and Vascular Medicine, University of Exeter Medical School, Barrack Road, Exeter EX2 5AX, United Kingdom, the National Institute for Health Research Exeter Clinical Research Facility, Royal Devon and Exeter National Health Service Foundation Trust, Exeter EX2 5DW, United Kingdom, and
| | - Kim M Gooding
- the Department of Diabetes and Vascular Medicine, University of Exeter Medical School, Barrack Road, Exeter EX2 5AX, United Kingdom, the National Institute for Health Research Exeter Clinical Research Facility, Royal Devon and Exeter National Health Service Foundation Trust, Exeter EX2 5DW, United Kingdom, and
| | - Francesco Casanova
- the Department of Diabetes and Vascular Medicine, University of Exeter Medical School, Barrack Road, Exeter EX2 5AX, United Kingdom, the National Institute for Health Research Exeter Clinical Research Facility, Royal Devon and Exeter National Health Service Foundation Trust, Exeter EX2 5DW, United Kingdom, and
| | - Tim J Mitchell
- the Institute of Microbiology and Infection, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Richard W Titball
- From the College of Life and Environmental Sciences, School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - C Peter Winlove
- the College of Engineering, Mathematics and Physical Sciences, School of Physics, University of Exeter, Exeter EX4 4QL, United Kingdom
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23
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Heath GR, Li M, Polignano IL, Richens JL, Catucci G, O’Shea P, Sadeghi SJ, Gilardi G, Butt JN, Jeuken LJC. Layer-by-Layer Assembly of Supported Lipid Bilayer Poly-l-Lysine Multilayers. Biomacromolecules 2015; 17:324-35. [DOI: 10.1021/acs.biomac.5b01434] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- George R. Heath
- School
of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Mengqiu Li
- School
of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | | | - Joanna L. Richens
- Cell
Biophysics Group, Institute of Biophysics, Imaging and Optical Science,
School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Gianluca Catucci
- Life
Sciences and Systems Biology, University of Torino, 10123, Turin, Italy
| | - Paul O’Shea
- Cell
Biophysics Group, Institute of Biophysics, Imaging and Optical Science,
School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Sheila J. Sadeghi
- Life
Sciences and Systems Biology, University of Torino, 10123, Turin, Italy
| | - Gianfranco Gilardi
- Life
Sciences and Systems Biology, University of Torino, 10123, Turin, Italy
| | - Julea N. Butt
- Centre
for Molecular and Structural Biochemistry, School of Biological Sciences,
and School of Chemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Lars J. C. Jeuken
- School
of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
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24
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Richens JL, Lane JS, Bramble JP, O'Shea P. The electrical interplay between proteins and lipids in membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1828-36. [DOI: 10.1016/j.bbamem.2015.03.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 03/16/2015] [Accepted: 03/18/2015] [Indexed: 11/17/2022]
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25
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Richens JL, Lane JS, Mather ML, O'Shea P. The interactions of squalene, alkanes and other mineral oils with model membranes; effects on membrane heterogeneity and function. J Colloid Interface Sci 2015; 457:225-31. [PMID: 26188729 DOI: 10.1016/j.jcis.2015.06.052] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/18/2015] [Accepted: 06/18/2015] [Indexed: 10/23/2022]
Abstract
Droplet interface bilayers (DIBs) offer many favourable facets as an artificial membrane system but the influence of any residual oil that remains in the bilayer following preparation is ill-defined. In this study the fluorescent membrane probes di-8-butyl-amino-naphthyl-ethylene-pyridinium-propyl-sulfonate (Di-8-ANEPPS) and Fluoresceinphosphatidylethanolamine (FPE) were used to help understand the nature of the phospholipid-oil interaction and to examine any structural and functional consequences of such interactions on membrane bilayer properties. Concentration-dependent modifications of the membrane dipole potential were found to occur in phospholipid vesicles exposed to a variety of different oils. Incorporation of oil into the lipid bilayer was shown to have no significant effect on the movement of fatty acids across the lipid bilayer. Changes in membrane heterogeneity were, however, demonstrated with increased microdomain formation being visible in the bilayer following exposure to mineral oil, pentadecane and squalene. As it is important that artificial systems provide an accurate representation of the membrane environment, careful consideration should be taken prior to the application of DIBs in studies of membrane structure and organisation.
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Affiliation(s)
- Joanna L Richens
- Cell Biophysics Group, Institute of Biophysics, Imaging and Optical Science, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom.
| | - Jordan S Lane
- Cell Biophysics Group, Institute of Biophysics, Imaging and Optical Science, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom.
| | - Melissa L Mather
- Cell Biophysics Group, Institute of Biophysics, Imaging and Optical Science, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom.
| | - Paul O'Shea
- Cell Biophysics Group, Institute of Biophysics, Imaging and Optical Science, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom.
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26
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Davis S, Davis BM, Richens JL, Vere KA, Petrov PG, Winlove CP, O'Shea P. α-Tocopherols modify the membrane dipole potential leading to modulation of ligand binding by P-glycoprotein. J Lipid Res 2015; 56:1543-50. [PMID: 26026069 DOI: 10.1194/jlr.m059519] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Indexed: 11/20/2022] Open
Abstract
α-Tocopherol (vitamin E) has attracted considerable attention as a potential protective or palliative agent. In vitro, its free radical-scavenging antioxidant action has been widely demonstrated. In vivo, however, vitamin E treatment exhibits negligible benefits against oxidative stress. α-Tocopherol influences lipid ordering within biological membranes and its derivatives have been suggested to inhibit the multi-drug efflux pump, P-glycoprotein (P-gp). This study employs the fluorescent membrane probe, 1-(3-sulfonatopropyl)-4-[β[2-(di-n-octylamino)-6-naphthyl]vinyl] pyridinium betaine, to investigate whether these effects are connected via influences on the membrane dipole potential (MDP), an intrinsic property of biological membranes previously demonstrated to modulate P-gp activity. α-Tocopherol and its non-free radical-scavenging succinate analog induced similar decreases in the MDP of phosphatidylcholine vesicles. α-Tocopherol succinate also reduced the MDP of T-lymphocytes, subsequently decreasing the binding affinity of saquinavir for P-gp. Additionally, α-tocopherol succinate demonstrated a preference for cholesterol-treated (membrane microdomain enriched) cells over membrane cholesterol-depleted cells. Microdomain disruption via cholesterol depletion decreased saquinavir's affinity for P-gp, potentially implicating these structures in the influence of α-tocopherol succinate on P-gp. This study provides evidence of a microdomain dipole potential-dependent mechanism by which α-tocopherol analogs influence P-gp activity. These findings have implications for the use of α-tocopherol derivatives for drug delivery across biological barriers.
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Affiliation(s)
- Sterenn Davis
- Biomedical Physics Group, School of Physics, University of Exeter, Exeter, United Kingdom
| | - Benjamin M Davis
- Cell Biophysics Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Joanna L Richens
- Cell Biophysics Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Kelly-Ann Vere
- Cell Biophysics Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Peter G Petrov
- Biomedical Physics Group, School of Physics, University of Exeter, Exeter, United Kingdom
| | - C Peter Winlove
- Biomedical Physics Group, School of Physics, University of Exeter, Exeter, United Kingdom
| | - Paul O'Shea
- Cell Biophysics Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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27
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Davis BM, Normando EM, Guo L, Turner LA, Nizari S, O'Shea P, Moss SE, Somavarapu S, Cordeiro MF. Topical delivery of Avastin to the posterior segment of the eye in vivo using annexin A5-associated liposomes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:1575-84. [PMID: 24596245 DOI: 10.1002/smll.201303433] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/31/2013] [Indexed: 05/25/2023]
Abstract
Effective delivery to the retina is presently one of the most challenging areas in drug development in ophthalmology, due to anatomical barriers preventing entry of therapeutic substances. Intraocular injection is presently the only route of administration for large protein therapeutics, including the anti-Vascular Endothelial Growth Factors Lucentis (ranibizumab) and Avastin (bevacizumab). Anti-VEGFs have revolutionised the management of age-related macular degeneration and have increasing indications for use as sight-saving therapies in diabetes and retinal vascular disease. Considerable resources have been allocated to develop non-invasive ocular drug delivery systems. It has been suggested that the anionic phospholipid binding protein annexin A5, may have a role in drug delivery. In the present study we demonstrate, using a combination of in vitro and in vivo assays, that the presence of annexin A5 can significantly enhance uptake and transcytosis of liposomal drug carrier systems across corneal epithelial barriers. This system is employed to deliver physiologically significant concentrations of Avastin to the posterior of the rat eye (127 ng/g) and rabbit retina (18 ng/g) after topical application. Our observations provide evidence to suggest annexin A5 mediated endocytosis can enhance the delivery of associated lipidic drug delivery vehicles across biological barriers, which may have therapeutic implications.
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Affiliation(s)
- Benjamin M Davis
- UCL Institute of Ophthalmology, University College London, Bath Street, London, EC1V 9EL, UK
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28
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Khmelinskaia A, Ibarguren M, de Almeida RFM, López DJ, Paixão VA, Ahyayauch H, Goñi FM, Escribá PV. Changes in membrane organization upon spontaneous insertion of 2-hydroxylated unsaturated fatty acids in the lipid bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:2117-2128. [PMID: 24490728 DOI: 10.1021/la403977f] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Recent research regarding 2-hydroxylated fatty acids (2OHFAs) showed clear evidence of their benefits in the treatment of cancer, inflammation, and neurodegenerative disorders such as Alzheimer's disease. Monolayer compressibility isotherms and isothermal titration calorimetry of 2OHFA (C18-C22) in phosphatidylcholine/phosphatidylethanolamine/sphingomyelin/cholesterol (1:1:1:1 mole ratio), a mixture that mimics the composition of mammalian plasma membrane, were performed to assess the membrane binding capacity of 2OHFAs and their natural, nonhydroxylated counterparts. The results show that 2OHFAs are surface-active substances that bind membranes through exothermic, spontaneous processes. The main effects of 2OHFAs are a decrease in lipid order, with a looser packing of the acyl chains, and a decreased dipole potential, regardless of the 2OHFAs' relative affinity for the lipid bilayer. The strongest effects are usually observed for 2-hydroxyarachidonic (C20:4) acid, and the weakest one, for 2-hydroxydocosahexaenoic acid (C22:6). In addition, 2OHFAs cause increased hydration, except in gel-phase membranes, which can be explained by the 2OHFA preference for membrane defects. Concerning the membrane dipole potential, the magnitude of the reduction induced by 2OHFAs was particularly marked in the liquid-ordered (lo) phase (cholesterol/sphingomyelin-rich) membranes, those where order reduction was the smallest, suggesting a disruption of cholesterol-sphingolipid interactions that are responsible for the large dipole potential in those membranes. Moreover, 2OHFA effects were larger than for both lo and ld phases separately in model membranes with liquid disordered (ld)/lo coexistence when both phases were present in significant amounts, possibly because of the facilitating effect of ld/lo domain interfaces. The specific and marked changes induced by 2OHFAs in several membrane properties suggest that the initial interaction with the membrane and subsequent reorganization might constitute an important step in their mechanisms of action.
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Affiliation(s)
- Alena Khmelinskaia
- Centro de Quimica e Bioquimica, DQB, Faculdade de Ciências da Universidade de Lisboa , Campo Grande, Ed. C8, 1749-016 Lisboa Portugal
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Vere KA, Richens JL, Lane JS, Harris HJ, Duggan J, O'Shea P. Evidence for sodium metasilicate receptors on the human osteoblast cell surface; spatial localization and binding properties. Mol Membr Biol 2013; 30:386-93. [PMID: 24147954 DOI: 10.3109/09687688.2013.843031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We report details of the interaction of sodium metasilicate with osteoblast cellular membranes using Fluoresceinphosphatidylethanolamine (FPE) as a fluorescent indicator of membrane interactions. Fluorescence imaging studies of the FPE-based indicator system revealed areas of localized binding that would be consistent with the presence of a structure with 'receptor-like' properties. From these results, it seems unlikely that silica binds 'non-specifically' to the osteoblast surface. Moreover, the receptors are localized into membrane domains. Such regions of the cell membrane could well be structures such as 'rafts' or other such localized domains within the membrane. The binding profile of silica with the osteoblast cell surface takes place with all the characteristics of a receptor-mediated process best represented by a cooperativity (sigmoidal) binding model with a Hill coefficient of 3.6.
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Affiliation(s)
- Kelly-Ann Vere
- Cell Biophysics Group, Institute of Biophysics, Imaging and Optical Science (IBIOS), School of Life Sciences, University of Nottingham , Nottingham , UK
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Ostroumova OS, Efimova SS, Schagina LV. Changes of dipole potential of phospholipid membranes resulted from flavonoid adsorption. Biophysics (Nagoya-shi) 2013. [DOI: 10.1134/s0006350913030123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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31
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Nankar SA, Bajaj P, Sravanthi R, Pande AH. Differential interaction of peptides derived from C-terminal domain of human apolipoprotein E with platelet activating factor analogs. Biochimie 2013; 95:1196-207. [DOI: 10.1016/j.biochi.2013.01.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 01/16/2013] [Indexed: 11/25/2022]
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Nankar SA, Pande AH. Physicochemical properties of bacterial pro-inflammatory lipids influence their interaction with apolipoprotein-derived peptides. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:853-62. [DOI: 10.1016/j.bbalip.2013.01.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Revised: 12/21/2012] [Accepted: 01/07/2013] [Indexed: 11/26/2022]
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Jewell SA, Petrov PG, Winlove CP. The effect of oxidative stress on the membrane dipole potential of human red blood cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:1250-8. [PMID: 23313455 DOI: 10.1016/j.bbamem.2012.12.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 12/21/2012] [Accepted: 12/31/2012] [Indexed: 02/09/2023]
Abstract
The membrane dipole potential (ψ(d)) is an important biophysical determinant of membrane function and a sensitive indicator of lipid organisation. In this study we have used the environmentally sensitive probe di-8-anepps to explore the effects of oxidative stress on the membrane dipole potential of human erythrocytes. Cells suspended in 0.15mM phosphate buffered saline containing 0.1mg/ml albumin maintained a mean value for ψ(d) of 270 (±20) mV over the course of 1hour. In the presence of 0.4mM cumene hydroperoxide there was an increase in ψ(d) of 14 (±7)%, accompanied by a decrease in cell diameter of ~14 (±2)%. Exposure of the cells to 0.4mM hydrogen peroxide caused ψ(d) to decrease by 13 (±8)% at the centre of the cell and 8 (±5)% at the edge whilst the diameter remained constant. In both cases the changes were equivalent to a change in transmembrane electric field of a magnitude of ~10MVm(-1), sufficient to influence membrane function. Raman microspectrometry supported the conclusion that cumene exerts its effect primarily on membrane lipids whilst hydrogen peroxide causes the formation of spectrin-haemoglobin complexes which stiffen the membrane.
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Affiliation(s)
- S A Jewell
- School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK.
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Kuo YC, Wang CC. Cationic solid lipid nanoparticles with primary and quaternary amines for release of saquinavir and biocompatibility with endothelia. Colloids Surf B Biointerfaces 2013; 101:101-5. [DOI: 10.1016/j.colsurfb.2012.06.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 06/01/2012] [Accepted: 06/06/2012] [Indexed: 11/16/2022]
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35
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Orsi M, Essex JW. Physical properties of mixed bilayers containing lamellar and nonlamellar lipids: insights from coarse-grain molecular dynamics simulations. Faraday Discuss 2013; 161:249-72; discussion 273-303. [DOI: 10.1039/c2fd20110k] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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36
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Efimova SS, Ostroumova OS. Effect of dipole modifiers on the magnitude of the dipole potential of sterol-containing bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:9908-14. [PMID: 22702338 DOI: 10.1021/la301653s] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The effects of various subclasses of flavonoids, Rose Bengal, and different styrylpyridinium dyes on the magnitude of the dipole potential of membranes composed of pure phospholipids and sterol-containing bilayers were investigated. Changes in the steady-state membrane conductance induced by cation-ionophore complexes were measured to examine the changes in the dipole potential of lipid bilayers. The characteristic parameters of the Langmuir adsorption isotherm for different flavonoids and Rose Bengal and the slope of the linear dependence of the dipole potential change on the aqueous concentrations of RH dyes were estimated. Chalcones (phloretin and phloridzin) and flavonols (quercetin and myricetin) strictly decrease the dipole potential of phospholipid- and sterol-containing membranes; the unsaturation of the C-ring and the hydrophobicity of the molecule contribute to the ability of the flavonoid to reduce the bilayer dipole potential. Rose Bengal decreases the magnitude of the bilayer dipole potential to a similar extent, but its affinity for membrane lipids is higher; the effects of RH dyes, chalcones, and phloroglucinol are determined by sterol concentration and type.
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Affiliation(s)
- Svetlana S Efimova
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg 194064, Russia
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Ciesielski F, Davis B, Rittig M, Bonev BB, O'Shea P. Receptor-independent interaction of bacterial lipopolysaccharide with lipid and lymphocyte membranes; the role of cholesterol. PLoS One 2012; 7:e38677. [PMID: 22685597 PMCID: PMC3369841 DOI: 10.1371/journal.pone.0038677] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 05/10/2012] [Indexed: 01/18/2023] Open
Abstract
Lipopolysaccharide (LPS) is a major constituent of bacterial outer membranes where it makes up the bulk of the outer leaflet and plays a key role as determinant of bacterial interactions with the host. Membrane-free LPS is known to activate T-lymphocytes through interactions with Toll-like receptor 4 via multiprotein complexes. In the present study, we investigate the role of cholesterol and membrane heterogeneities as facilitators of receptor-independent LPS binding and insertion, which underpin bacterial interactions with the host in symbiosis, pathogenesis and cell invasion. We use fluorescence spectroscopy to investigate the interactions of membrane-free LPS from intestinal Gram-negative organisms with cholesterol-containing model membranes and with T-lymphocytes. LPS preparations from Klebsiella pneumoniae and Salmonella enterica were found to bind preferentially to mixed lipid membranes by comparison to pure PC bilayers. The same was observed for LPS from the symbiote Escherichia coli but with an order of magnitude higher dissociation constant. Insertion of LPS into model membranes confirmed the preference for sphimgomyelin/cholesterol-containing systems. LPS insertion into Jurkat T-lymphocyte membranes reveals that they have a significantly greater LPS-binding capacity by comparison to methyl-β-cyclodextrin cholesterol-depleted lymphocyte membranes, albeit at slightly lower binding rates.
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Affiliation(s)
- Filip Ciesielski
- School of Biomedical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Benjamin Davis
- School of Biology, University of Nottingham, Nottingham, United Kingdom
| | - Michael Rittig
- School of Biomedical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Boyan B. Bonev
- School of Biomedical Sciences, University of Nottingham, Nottingham, United Kingdom
- * E-mail: (BBB); (PS)
| | - Paul O'Shea
- School of Biology, University of Nottingham, Nottingham, United Kingdom
- * E-mail: (BBB); (PS)
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38
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Ostroumova OS, Efimova SS, Schagina LV. Probing amphotericin B single channel activity by membrane dipole modifiers. PLoS One 2012; 7:e30261. [PMID: 22276169 PMCID: PMC3261894 DOI: 10.1371/journal.pone.0030261] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 12/12/2011] [Indexed: 12/03/2022] Open
Abstract
The effects of dipole modifiers and their structural analogs on the single channel activity of amphotericin B in sterol-containing planar phosphocholine membranes are studied. It is shown that the addition of phloretin in solutions bathing membranes containing cholesterol or ergosterol decreases the conductance of single amphotericin B channels. Quercetin decreases the channel conductance in cholesterol-containing bilayers while it does not affect the channel conductance in ergosterol-containing membranes. It is demonstrated that the insertion of styryl dyes, such as RH 421, RH 237 or RH 160, in bilayers with either cholesterol or ergosterol leads to the increase of the current amplitude of amphotericin B pores. Introduction of 5α-androstan-3β-ol into a membrane-forming solution increases the amphotericin B channel conductance in a concentration-dependent manner. All the effects are likely to be attributed to the influence of the membrane dipole potential on the conductance of single amphotericin B channels. However, specific interactions of some dipole modifiers with polyene-sterol complexes might also contribute to the activity of single amphotericin B pores. It has been shown that the channel dwell time increases with increasing sterol concentration, and it is higher for cholesterol-containing membranes than for bilayers including ergosterol, 6-ketocholestanol, 7-ketocholestanol or 5α-androstan-3β-ol. These findings suggest that the processes of association/dissociation of channel forming molecules depend on the membrane fluidity.
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Affiliation(s)
- Olga S Ostroumova
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg, Russia.
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39
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Zhan H, Lazaridis T. Influence of the membrane dipole potential on peptide binding to lipid bilayers. Biophys Chem 2011; 161:1-7. [PMID: 22100997 DOI: 10.1016/j.bpc.2011.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Revised: 10/21/2011] [Accepted: 10/25/2011] [Indexed: 12/15/2022]
Abstract
The implicit membrane model IMM1 is extended to include the membrane dipole potential and applied to molecular dynamics simulations of the helical peptides alamethicin, WALP23, influenza hemagglutinin fusion peptide, HIV fusion peptide, magainin, and the pre-sequence of cytochrome c oxidase subunit IV (p25). The results show that the orientation of the peptides in the membrane can be influenced by the dipole potential. The binding affinity of all peptides except for the hemagglutinin fusion peptide decreases upon increase of the dipole potential. The changes in both orientation and binding affinity are explained by the interaction of the dipole potential with the helix backbone dipole and ionic side-chains. In general, peptides that tend to insert the N-terminus in the membrane and/or have positively charged side chains will lose binding affinity upon increase of the dipole potential.
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Affiliation(s)
- Huan Zhan
- Department of Chemistry, City College of New York/CUNY, New York, NY 10031, USA
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40
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Mereuta L, Asandei A, Luchian T. Meet me on the other side: trans-bilayer modulation of a model voltage-gated ion channel activity by membrane electrostatics asymmetry. PLoS One 2011; 6:e25276. [PMID: 21980414 PMCID: PMC3181326 DOI: 10.1371/journal.pone.0025276] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 08/30/2011] [Indexed: 12/03/2022] Open
Abstract
While it is accepted that biomembrane asymmetry is generated by proteins and phospholipids distribution, little is known about how electric changes manifested in a monolayer influence functional properties of proteins localized on the opposite leaflet. Herein we used single-molecule electrophysiology and investigated how asymmetric changes in the electrostatics of an artificial lipid membrane monolayer, generated oppositely from where alamethicin - a model voltage-gated ion channel - was added, altered peptide activity. We found that phlorizin, a membrane dipole potential lowering amphiphile, augmented alamethicin activity and transport features, whereas the opposite occurred with RH-421, which enhances the monolayer dipole potential. Further, the monolayer surface potential was decreased via adsorption of sodium dodecyl sulfate, and demonstrated that vectorial modification of it also affected the alamethicin activity in a predictive manner. A new paradigm is suggested according to which asymmetric changes in the monolayer dipole and surface potential extend their effects spatially by altering the intramembrane potential, whose gradient is sensed by distantly located peptides.
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Affiliation(s)
- Loredana Mereuta
- Department of Physics, Laboratory of Molecular Biophysics and Medical Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Alina Asandei
- Department of Physics, Laboratory of Molecular Biophysics and Medical Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Tudor Luchian
- Department of Physics, Laboratory of Molecular Biophysics and Medical Physics, Alexandru I. Cuza University, Iasi, Romania
- * E-mail:
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41
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Orsi M, Noro MG, Essex JW. Dual-resolution molecular dynamics simulation of antimicrobials in biomembranes. J R Soc Interface 2011; 8:826-41. [PMID: 21131331 PMCID: PMC3104353 DOI: 10.1098/rsif.2010.0541] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 11/09/2010] [Indexed: 11/12/2022] Open
Abstract
Triclocarban and triclosan, two potent antibacterial molecules present in many consumer products, have been subject to growing debate on a number of issues, particularly in relation to their possible role in causing microbial resistance. In this computational study, we present molecular-level insights into the interaction between these antimicrobial agents and hydrated phospholipid bilayers (taken as a simple model for the cell membrane). Simulations are conducted by a novel 'dual-resolution' molecular dynamics approach which combines accuracy with efficiency: the antimicrobials, modelled atomistically, are mixed with simplified (coarse-grain) models of lipids and water. A first set of calculations is run to study the antimicrobials' transfer free energies and orientations as a function of depth inside the membrane. Both molecules are predicted to preferentially accumulate in the lipid headgroup-glycerol region; this finding, which reproduces corresponding experimental data, is also discussed in terms of a general relation between solute partitioning and the intramembrane distribution of pressure. A second set of runs involves membranes incorporated with different molar concentrations of antimicrobial molecules (up to one antimicrobial per two lipids). We study the effects induced on fundamental membrane properties, such as the electron density, lateral pressure and electrical potential profiles. In particular, the analysis of the spontaneous curvature indicates that increasing antimicrobial concentrations promote a 'destabilizing' tendency towards non-bilayer phases, as observed experimentally. The antimicrobials' influence on the self-assembly process is also investigated. The significance of our results in the context of current theories of antimicrobial action is discussed.
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Affiliation(s)
- Mario Orsi
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Massimo G. Noro
- Unilever R&D Port Sunlight, Quarry Road East, Bebington, Wirral, CH63 3JW, UK
| | - Jonathan W. Essex
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
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42
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Robinson D, Besley NA, O'shea P, Hirst JD. Water order profiles on phospholipid/cholesterol membrane bilayer surfaces. J Comput Chem 2011; 32:2613-8. [DOI: 10.1002/jcc.21840] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 04/20/2011] [Accepted: 04/20/2011] [Indexed: 11/11/2022]
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43
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Kar S, Tillu VA, Meena SC, Pande AH. Closely related oxidized phospholipids differentially modulate the physicochemical properties of lipid particles. Chem Phys Lipids 2011; 164:54-61. [DOI: 10.1016/j.chemphyslip.2010.10.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 10/21/2010] [Accepted: 10/26/2010] [Indexed: 01/08/2023]
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44
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Matos PM, Freitas T, Castanho MARB, Santos NC. The role of blood cell membrane lipids on the mode of action of HIV-1 fusion inhibitor sifuvirtide. Biochem Biophys Res Commun 2010; 403:270-4. [PMID: 21075080 DOI: 10.1016/j.bbrc.2010.11.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 11/03/2010] [Indexed: 11/29/2022]
Abstract
Sifuvirtide is a gp41 based peptide that inhibits HIV-1 fusion with the host cells and is currently under clinical trials. Previous studies showed that sifuvirtide partitions preferably to saturated phosphatidylcholine lipid membranes, instead of fluid-phase lipid vesicles. We extended the study to the interaction of the peptide with circulating blood cells, by using the dipole potential sensitive probe di-8-ANEPPS. Sifuvirtide decreased the dipole potential of erythrocyte and lymphocyte membranes in a concentration dependent manner, demonstrating its interaction. Also, the lipid selectivity of the peptide towards more rigid phosphatidylcholines was confirmed based on the dipole potential variations. Overall, the interaction of the peptide with the cell membranes is a contribution of different lipid preferences that presumably directs the peptide towards raft-like domains where the receptors are located, facilitating the reach of the peptide to its molecular target, the gp41 in its pre-fusion conformation.
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Affiliation(s)
- Pedro M Matos
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisbon, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
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45
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Davis BM, Jensen R, Williams P, O'Shea P. The interaction of N-acylhomoserine lactone quorum sensing signaling molecules with biological membranes: implications for inter-kingdom signaling. PLoS One 2010; 5:e13522. [PMID: 20975958 PMCID: PMC2958149 DOI: 10.1371/journal.pone.0013522] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 09/24/2010] [Indexed: 01/28/2023] Open
Abstract
Background The long chain N-acylhomoserine lactone (AHL) quorum sensing signal molecules released by Pseudomonas aeruginosa have long been known to elicit immunomodulatory effects through a process termed inter-kingdom signaling. However, to date very little is known regarding the exact mechanism of action of these compounds on their eukaryotic targets. Methodology/Principal Findings The use of the membrane dipole fluorescent sensor di-8-ANEPPS to characterise the interactions of AHL quorum sensing signal molecules, N-(3-oxotetradecanoyl)-L-homoserine lactone (3-oxo-C14-HSL), N-(3-oxododecanoyl)homoserine-L-lactone (3-oxo-C12-HSL) and N-(3-oxodecanoyl) homoserine-L-lactone (3-oxo-C10 HSL) produced by Pseudomonas aeruginosa with model and cellular membranes is reported. The interactions of these AHLs with artificial membranes reveal that each of the compounds is capable of membrane interaction in the micromolar concentration range causing significant modulation of the membrane dipole potential. These interactions fit simple hyperbolic binding models with membrane affinity increasing with acyl chain length. Similar results were obtained with T-lymphocytes providing the evidence that AHLs are capable of direct interaction with the plasma membrane. 3-oxo-C12-HSL interacts with lymphocytes via a cooperative binding model therefore implying the existence of an AHL membrane receptor. The role of cholesterol in the interactions of AHLs with membranes, the significance of modulating cellular dipole potential for receptor conformation and the implications for immune modulation are discussed. Conclusions/ Significance Our observations support previous findings that increasing AHL lipophilicity increases the immunomodulatory activity of these quorum compounds, while providing evidence to suggest membrane interaction plays an important role in quorum sensing and implies a role for membrane microdomains in this process. Finally, our results suggest the existence of a eukaryotic membrane-located system that acts as an AHL receptor.
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Affiliation(s)
- Benjamin Michael Davis
- Cell Biophysics Group, Institute of Biophysics, Imaging and Optical Science, University of Nottingham, Nottingham, United Kingdom
| | - Rasmus Jensen
- School of Molecular Medical Sciences, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Paul Williams
- School of Molecular Medical Sciences, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Paul O'Shea
- Cell Biophysics Group, Institute of Biophysics, Imaging and Optical Science, University of Nottingham, Nottingham, United Kingdom
- * E-mail:
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46
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Simard JR, Meshulam T, Pillai BK, Kirber MT, Brunaldi K, Xu S, Pilch PF, Hamilton JA. Caveolins sequester FA on the cytoplasmic leaflet of the plasma membrane, augment triglyceride formation, and protect cells from lipotoxicity. J Lipid Res 2010; 51:914-22. [PMID: 20388923 DOI: 10.1194/jlr.m900251] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Ectopic expression of caveolin-1 in HEK293 cells enhances FA sequestration in membranes as measured by a pH-sensitive fluorescent dye (1). We hypothesized that sequestration of FA is due to the enrichment of caveolin in the cytosolic leaflet and its ability to facilitate the formation of lipid rafts to buffer high FA levels. Here we show that ec-topic expression of caveolin-3 also results in enhanced FA sequestration. To further discriminate the effect that caveolins have on transmembrane FA movement and distribution, we labeled the outer membrane leaflet with fluorescein-phosphatidylethanolamine (FPE), whose emission is quenched by the presence of FA anions. Real-time measurements made with FPE and control experiments with positively charged fatty amines support our hypothesis that caveolins promote localization of FA anions through interactions with basic amino acid residues (lysines and arginines) present at the C termini of caveolins-1 and -3.
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Affiliation(s)
- Jeffrey R Simard
- Department of Biophysics and Physiology, Boston University School of Medicine, Boston, MA, USA
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47
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Simard JR, Meshulam T, Pillai BK, Kirber MT, Brunaldi K, Xu S, Pilch PF, Hamilton JA. Caveolins sequester FA on the cytoplasmic leaflet of the plasma membrane, augment triglyceride formation, and protect cells from lipotoxicity. J Lipid Res 2010. [DOI: 10.1194/jlr.m900251-jlr200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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48
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Orsi M, Michel J, Essex JW. Coarse-grain modelling of DMPC and DOPC lipid bilayers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:155106. [PMID: 21389551 DOI: 10.1088/0953-8984/22/15/155106] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Our recently developed coarse-grain model for dimyristoylphosphatidylcholine (DMPC) has been improved and extended to dioleylphosphatidylcholine (DOPC), a more typical constituent of real biological membranes. Single-component DMPC and DOPC bilayers have been simulated using microsecond-long molecular dynamics. We investigated properties that are difficult or impossible to access experimentally, such as the pressure distribution, the spontaneous curvature and the diffusion pattern of individual lipid molecules. Moreover, we studied the dipole potential, a basic physical feature of paramount biological importance that cannot be currently modelled by other coarse-grain approaches. In fact, a complete representation of the system electrostatics and a realistic description of the water component make our method unique amongst the existing coarse-grain membrane models. The spontaneous permeation of water, a phenomenon out of reach of standard atomistic models, was also observed and quantified; this was possible thanks to the efficiency of our model, which is about two orders of magnitude less computationally expensive than atomic-level counterparts. Results are generally in good agreement with the literature data. Further model extensions and future applications are proposed.
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Affiliation(s)
- Mario Orsi
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
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49
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Przybylo M, Borowik T, Langner M. Fluorescence Techniques for Determination of the Membrane Potentials in High Throughput Screening. J Fluoresc 2010; 20:1139-57. [DOI: 10.1007/s10895-010-0665-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 04/05/2010] [Indexed: 01/14/2023]
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50
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Intact lipid rafts regulate HIV-1 Tat protein-induced activation of the Rho signaling and upregulation of P-glycoprotein in brain endothelial cells. J Cereb Blood Flow Metab 2010; 30:522-33. [PMID: 19794400 PMCID: PMC2949153 DOI: 10.1038/jcbfm.2009.214] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Rho signaling has an essential function in human immunodeficiency virus (HIV)-1-mediated disruption of the integrity of the blood-brain barrier (BBB). However, it is unknown how membrane domains, such as lipid rafts, can influence HIV-1-mediated activation of the Rho pathway and how these processes can affect the expression of the efflux transporters at the BBB level. This study is focused on the function of HIV-1 protein Tat in activation of the Rho signaling and upregulation of P-glycoprotein (P-gp) in human brain endothelial cells. Treatment with Tat markedly elevated GTP-RhoA levels and the potential downstream effectors, such as myosin phosphatase target subunit 1 and myosin light chain. In addition, Tat upregulated expression and promoter activity of P-gp as well as its efflux function. Inhibition of the Rho signaling cascade effectively blocked P-gp overexpression at the level of promoter activity. Disruption of lipid rafts by depletion of membrane cholesterol by methyl-beta-cyclodextrin, but not caveolin-1 silencing, also abolished Tat-mediated RhoA activation and P-gp upregulation. The present data indicate the critical function of intact lipid rafts and the Rho signaling in HIV-1-mediated upregulation of P-gp and potential development of drug resistance in brain endothelial cells.
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