1
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Pandey Y, Ingold A, Kumar N, Zenobi R. Nanoscale visualization of phase separation in binary supported lipid monolayer using tip-enhanced Raman spectroscopy. NANOSCALE 2024; 16:10578-10583. [PMID: 38767416 PMCID: PMC11154864 DOI: 10.1039/d4nr00816b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 05/05/2024] [Indexed: 05/22/2024]
Abstract
Supported lipid membranes are an important model system to study the phase separation behavior at the nanoscale. However, the conventional nanoanalytical tools often fail to provide reliable chemical characterization of the phase separated domains in a non-destructive and label-free manner. This study demonstrates the application of scanning tunneling microscopy-based tip-enhanced Raman spectroscopy (TERS) to study the nanoscale phase separation in supported d62-DPPC : DOPC lipid monolayers. Hyperspectral TERS imaging successfully revealed a clear segregation of the d62-DPPC-rich and DOPC-rich domains. Interestingly, nanoscale deposits of d62-DPPC were observed inside the DOPC-rich domains and vice versa. High-resolution TERS imaging also revealed the presence of a 40-120 nm wide interfacial region between the d62-DPPC-rich and DOPC-rich domains signifying a smooth transition rather than a sharp boundary between them. The novel insights obtained in this study demonstrate the effectiveness of TERS in studying binary lipid monolayers at the nanoscale.
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Affiliation(s)
- Yashashwa Pandey
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland.
| | - Andrea Ingold
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland.
| | - Naresh Kumar
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland.
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland.
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2
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Henderson RDE, Mei N, Xu Y, Gaikwad R, Wettig S, Leonenko Z. Nanoscale Structure of Lipid-Gemini Surfactant Mixed Monolayers Resolved with AFM and KPFM Microscopy. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:572. [PMID: 38607107 PMCID: PMC11013119 DOI: 10.3390/nano14070572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 03/18/2024] [Accepted: 03/20/2024] [Indexed: 04/13/2024]
Abstract
Drug delivery vehicles composed of lipids and gemini surfactants (GS) are promising in gene therapy. Tuning the composition and properties of the delivery vehicle is important for the efficient load and delivery of DNA fragments (genes). In this paper, we studied novel gene delivery systems composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-dipalmitoyl-sn-3-phosphocholine (DPPC), and GS of the type N,N-bis(dimethylalkyl)-α,ω-alkanediammonium dibromide at different ratios. The nanoscale properties of the mixed DOPC-DPPC-GS monolayers on the surface of the gene delivery system were studied using atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM). We demonstrate that lipid-GS mixed monolayers result in the formation of nanoscale domains that vary in size, height, and electrical surface potential. We show that the presence of GS can impart significant changes to the domain topography and electrical surface potential compared to monolayers composed of lipids alone.
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Affiliation(s)
- Robert D. E. Henderson
- Department of Physics & Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (R.D.E.H.); (N.M.); (Y.X.)
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Nanqin Mei
- Department of Physics & Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (R.D.E.H.); (N.M.); (Y.X.)
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Yue Xu
- Department of Physics & Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (R.D.E.H.); (N.M.); (Y.X.)
| | - Ravi Gaikwad
- Department of Physics & Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (R.D.E.H.); (N.M.); (Y.X.)
| | - Shawn Wettig
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- School of Pharmacy, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Zoya Leonenko
- Department of Physics & Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada; (R.D.E.H.); (N.M.); (Y.X.)
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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3
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Dobrynina EA, Zykova VA, Surovtsev NV. In-plane and out-of-plane gigahertz sound velocities of saturated and unsaturated phospholipid bilayers from cryogenic to room temperatures. Chem Phys Lipids 2023; 256:105335. [PMID: 37579988 DOI: 10.1016/j.chemphyslip.2023.105335] [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: 03/31/2023] [Revised: 06/23/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
Here, we examined the gigahertz sound velocities of hydrated multibilayers of saturated (1,2-dimyristoyl-sn-glycero-3-phosphocholine, DMPC) and unsaturated (1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC) phospholipids by Brillouin spectroscopy. Out-of-plane and in-plane (lateral) phonons were studied independently of each other. Similar strong temperature dependences of the sound velocities were found for phonons of both types. The sound velocities in the low-temperature limit were two-fold higher than that at physiological temperatures; a significant part of the changes in sound velocity occurs in the solid-like gel phase. The factors that may be involved in the peculiar behavior of sound velocity include changes in the chain conformational state, relaxation susceptibility, changes in the elastic modulus at infinite frequencies, and lateral packing of molecules.
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Affiliation(s)
- E A Dobrynina
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - V A Zykova
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - N V Surovtsev
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia.
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4
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Zhukov A, Popov V. Eukaryotic Cell Membranes: Structure, Composition, Research Methods and Computational Modelling. Int J Mol Sci 2023; 24:11226. [PMID: 37446404 DOI: 10.3390/ijms241311226] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/03/2023] [Accepted: 07/06/2023] [Indexed: 07/15/2023] Open
Abstract
This paper deals with the problems encountered in the study of eukaryotic cell membranes. A discussion on the structure and composition of membranes, lateral heterogeneity of membranes, lipid raft formation, and involvement of actin and cytoskeleton networks in the maintenance of membrane structure is included. Modern methods for the study of membranes and their constituent domains are discussed. Various simplified models of biomembranes and lipid rafts are presented. Computer modelling is considered as one of the most important methods. This is stated that from the study of the plasma membrane structure, it is desirable to proceed to the diverse membranes of all organelles of the cell. The qualitative composition and molar content of individual classes of polar lipids, free sterols and proteins in each of these membranes must be considered. A program to create an open access electronic database including results obtained from the membrane modelling of individual cell organelles and the key sites of the membranes, as well as models of individual molecules composing the membranes, has been proposed.
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Affiliation(s)
- Anatoly Zhukov
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, 127276 Moscow, Russia
| | - Valery Popov
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, 127276 Moscow, Russia
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5
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Zykova VA, Surovtsev NV. Brillouin Spectroscopy of Binary Phospholipid-Cholesterol Bilayers. APPLIED SPECTROSCOPY 2022; 76:1206-1215. [PMID: 35712869 DOI: 10.1177/00037028221111147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Multicomponent lipid bilayers are used as models for searching the origin of spatial heterogeneities in biomembranes called lipid rafts, implying the coexistence of domains of different phases and compositions within the lipid bilayer. The spatial organization of multicomponent lipid bilayers on a scale of a hundred nanometers remains unknown. Brillouin spectroscopy providing information about the acoustic phonons with the wavelength of several hundred nanometers has an unexplored potential for this problem. Here, we applied Brillouin spectroscopy for three binary bilayers composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-palmitoyl-sn-glycero-3-phosphocholine (DPPC), and cholesterol. The Brillouin experiment for the oriented planar multibilayers was realized for two scattering geometries involving phonons for the lateral and normal directions of the propagation. The DPPC-DOPC mixtures known for the coexistence of the solid-ordered and liquid-disordered phases had bimodal Brillouin peaks, revealing the phase domains with sizes more than a hundred nanometers. Analysis of the Brillouin data for the binary mixtures concluded that the lateral phonons are preferable for testing the lateral homogeneity of the bilayers, while the phonons spreading across the bilayers are sensitive to the layered packing at the mesoscopic scale.
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Affiliation(s)
- Valeria A Zykova
- 104673Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, Russia
| | - Nikolay V Surovtsev
- 104673Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, Russia
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6
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Taguchi S, Okamoto Y, Suga K, Jung HS, Umakoshi H. Preparation of Planar Lipid Bilayer Membrane by Utilizing Bicelles and Its Characterization. KAGAKU KOGAKU RONBUN 2022. [DOI: 10.1252/kakoronbunshu.48.175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shogo Taguchi
- Department of Chemical Engineering and Materials Science, Graduate School of Engineering, University of Hyogo
| | - Yukihiro Okamoto
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University
| | - Keishi Suga
- Department of Chemical Engineering, Tohoku University
| | - Ho-Sup Jung
- Center for Food and Bioconvergence, Department of Food Science and Biotechnology, Seoul National University
| | - Hiroshi Umakoshi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University
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7
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Inimitable Impacts of Ceramides on Lipid Rafts Formed in Artificial and Natural Cell Membranes. MEMBRANES 2022; 12:membranes12080727. [PMID: 35893445 PMCID: PMC9330320 DOI: 10.3390/membranes12080727] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 02/02/2023]
Abstract
Ceramide is the simplest precursor of sphingolipids and is involved in a variety of biological functions ranging from apoptosis to the immune responses. Although ceramide is a minor constituent of plasma membranes, it drastically increases upon cellular stimulation. However, the mechanistic link between ceramide generation and signal transduction remains unknown. To address this issue, the effect of ceramide on phospholipid membranes has been examined in numerous studies. One of the most remarkable findings of these studies is that ceramide induces the coalescence of membrane domains termed lipid rafts. Thus, it has been hypothesised that ceramide exerts its biological activity through the structural alteration of lipid rafts. In the present article, we first discuss the characteristic hydrogen bond functionality of ceramides. Then, we showed the impact of ceramide on the structures of artificial and cell membranes, including the coalescence of the pre-existing lipid raft into a large patch called a signal platform. Moreover, we proposed a possible structure of the signal platform, in which sphingomyelin/cholesterol-rich and sphingomyelin/ceramide-rich domains coexist. This structure is considered to be beneficial because membrane proteins and their inhibitors are separately compartmentalised in those domains. Considering the fact that ceramide/cholesterol content regulates the miscibility of those two domains in model membranes, the association and dissociation of membrane proteins and their inhibitors might be controlled by the contents of ceramide and cholesterol in the signal platform.
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8
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Zaytseva YV, Zaytseva IV, Surovtsev NV. Conformational state diagram of DOPC/DPPC d62/cholesterol mixtures. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183869. [PMID: 35063400 DOI: 10.1016/j.bbamem.2022.183869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/09/2022] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
Raman spectra of aqueous suspensions of vesicles composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), deuterated 1,2-dipalmitoyl-d62-sn-glycero-3-phosphocholine (DPPCd62), and cholesterol (Chol) were studied at room temperature to determine the conformational states of the phospholipid hydrocarbon chains. Deuteration of DPPCd62 allowed us to characterize the conformational states of DOPC and DPPCd62 independently. The parameters of Raman peaks, which are sensitive to the conformational order, were studied in a wide range of compositions. It was found that the DOPC molecules are conformationally disordered for all compositions. The conformational state of the DPPCd62 molecules changes with composition. Their conformational state is influenced by cholesterol-induced partial disordering and DOPC solvation, transforming the DPPC molecules into the disordered state. The conformational state diagram from the Raman experiment was compared with outcomes from the differential scanning calorimetry (DSC) experiment. The Raman spectra also revealed that the DPPC molecules coexist in the disordered and all-trans ordered states for the DOPC/DPPCd62/Chol mixtures except for the pure liquid-disordered phase.
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Affiliation(s)
- Yu V Zaytseva
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - I V Zaytseva
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - N V Surovtsev
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia.
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9
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Shrestha R, Chen D, Frank P, Nissley DV, Turbyville TJ. Recapitulation of cell-like KRAS4b membrane dynamics on complex biomimetic membranes. iScience 2022; 25:103608. [PMID: 35106460 PMCID: PMC8786645 DOI: 10.1016/j.isci.2021.103608] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/30/2021] [Accepted: 12/08/2021] [Indexed: 12/22/2022] Open
Abstract
Understanding the spatiotemporal distribution and dynamics of RAS on the plasma membrane (PM) is the key for elucidating the molecular mechanisms of the RAS signaling pathway. Single particle tracking (SPT) experiments show that in cells, KRAS diffuses in at least three interchanging states on the cellular PM; however, KRAS remains monomeric and always shows homogeneous diffusion on artificial membranes. Here, we show for the first time on a supported lipid bilayer composed of heterogeneous lipid components that we can recapitulate the three-state diffusion of KRAS seen in cells. The use of a biologically relevant eight-lipid system opens a new frontier in the biophysical studies of RAS and other membrane associated proteins on a biomimetic system that recapitulates the complexity of a cellular PM. KRAS4b shows homogeneous diffusion on simple 2-lipids bilayer KRAS4b shows a cell-like, three-state diffusion on a complex 8-lipid bilayer Phase separation in lipids favors the multi-state diffusion of KRAS4b The complex lipid composition favors RAS nanoclustering irrespective of nucleotide state
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Affiliation(s)
- Rebika Shrestha
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702, USA
| | - De Chen
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702, USA
| | - Peter Frank
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702, USA
| | - Dwight V Nissley
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702, USA
| | - Thomas J Turbyville
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702, USA
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10
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Hsieh MK, Yu Y, Klauda JB. All-Atom Modeling of Complex Cellular Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:3-17. [PMID: 34962814 DOI: 10.1021/acs.langmuir.1c02084] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cell membranes are composed of a variety of lipids and proteins where they interact with each other to fulfill their roles. The first step in modeling these interactions in molecular simulations is to have reliable mimetics of the membrane's lipid environment. This Feature Article presents our recent efforts to model complex cellular membranes using all-atom force fields. A short review of the CHARMM36 (C36) lipid force field and its recent update to incorporate the long-range dispersion is presented. Key examples of model membranes mimicking various species and organelles are given. These include single-celled organisms such as bacteria (E. coli., chlamydia, and P. aeruginosa) and yeast (plasma membrane, endoplasmic reticulum, and trans-Golgi network) and more advanced ones such as plants (soybean and Arabidopsis thaliana) and mammals (ocular lens, stratum corneum, and peripheral nerve myelin). Leaflet asymmetry in composition has also been applied to some of these models. With the increased lipid diversity in the C36 lipid FF, these complex models can better reflect the structural, mechanical, and dynamic properties of realistic membranes and open an opportunity to study biological processes involving other molecules.
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11
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Matsubara T, IIjima K, Kojima T, Hirai M, Miyamoto E, Sato T. Heterogeneous Ganglioside-Enriched Nanoclusters with Different Densities in Membrane Rafts Detected by a Peptidyl Molecular Probe. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:646-654. [PMID: 33398996 DOI: 10.1021/acs.langmuir.0c02387] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The specific features of the lateral distribution of gangliosides play key roles in cell-cell communications and the onset of various diseases related to the plasma membrane. We herein demonstrated that an artificial peptide identified from a phage-displayed library is available as a molecular probe for specific ganglioside nanoclustering sites in caveolae/membrane rafts on the cell surface. Atomic force microscopy studies indicated that the peptide specifically binds to the highly enriched monosialoganglioside GM1 nanodomains of reconstituted lipid bilayers composed of GM1, sphingomyelin, cholesterol, and unsaturated phospholipids. The ganglioside-containing area recognized by the peptide on the surface of PC12 cells was part of the area recognized by the cholera toxin B subunit, which has high affinity for GM1. Furthermore, the peptide bound to the cell surface after a treatment with methyl-β-cyclodextrin (MβCD), which disrupts membrane rafts by removing cholesterol. The present results indicate that there are heterogeneous ganglioside clusters with different ganglioside densities in caveolae/membrane rafts, and the peptidyl probe selectively recognizes the high-density ganglioside nanodomain that resists the MβCD treatment. This peptidyl probe will be useful for obtaining information on the lipid organization of the cell membrane and will help clarify the mechanisms by which the lateral distribution of gangliosides affects biological functions and the onset of diseases.
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Affiliation(s)
- Teruhiko Matsubara
- Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Kazutoshi IIjima
- Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Takahiro Kojima
- Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Miwa Hirai
- Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Erika Miyamoto
- Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Toshinori Sato
- Department of Biosciences and Informatics, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
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12
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Siddiquee AM, Houri A, Messalea KA, Lin J, Daeneke T, Abbey B, Mechler A, Kou S. Nanoscale Probing of Cholesterol-Rich Domains in Single Bilayer Dimyristoyl-Phosphocholine Membranes Using Near-Field Spectroscopic Imaging. J Phys Chem Lett 2020; 11:9476-9484. [PMID: 33108191 DOI: 10.1021/acs.jpclett.0c02192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cholesterol is believed to induce the formation of membrane domains, "rafts", which are implicated in a range of natural and pathologic membrane processes. Therefore, it is important to understand the role that cholesterol plays in the formation of these structures. Here, we use label-free spectroscopic imaging to investigate cholesterol fractioning in supported bilayer membranes at nanoscale. Scattering-type scanning near-field optical microscopy (s-SNOM) was used to visualize the formation of cholesterol-induced domains in 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membranes. Our results revealed the coexistence of phase separated domains in DMPC lipids with 10 mol % cholesterol content, whereas a mostly homogeneous bilayer was found at low (5 mol %) and high (15 mol %) cholesterol content. Near-field nano-FTIR spectroscopy was used to identify the cholesterol-rich domains based on their qualitative chemical compositions. It was determined that cholesterol binds to phosphodiester and alkyl glycerol ester moieties, likely via hydrogen bonding of the alcohol to either of the ester oxygens. The results also confirm the existence of an ideal cholesterol-lipid mixture ratio (∼15:85) with a geometrically defined packing. At lower cholesterol content there is phase separation between liquid ordered and almost neat DMPC domains. Thus, the liquid ordered phase exists at an energy minimum at a given lipid-cholesterol ratio.
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Affiliation(s)
- Arif M Siddiquee
- Department of Electronic Science, Fujian Research Center for Solid-State Lighting, Xiamen University, Xiamen 361005, China
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Melbourne, Victoria 3086, Australia
| | - Aamd Houri
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria 3086, Australia
| | - Kibret A Messalea
- School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Jiao Lin
- School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Torben Daeneke
- School of Engineering, RMIT University, Melbourne, Victoria 3001, Australia
| | - Brian Abbey
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Melbourne, Victoria 3086, Australia
| | - Adam Mechler
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria 3086, Australia
| | - Shanshan Kou
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Melbourne, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Melbourne, Victoria 3086, Australia
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13
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Redondo-Morata L, Losada-Pérez P, Giannotti MI. Lipid bilayers: Phase behavior and nanomechanics. CURRENT TOPICS IN MEMBRANES 2020; 86:1-55. [PMID: 33837691 DOI: 10.1016/bs.ctm.2020.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lipid membranes are involved in many physiological processes like recognition, signaling, fusion or remodeling of the cell membrane or some of its internal compartments. Within the cell, they are the ultimate barrier, while maintaining the fluidity or flexibility required for a myriad of processes, including membrane protein assembly. The physical properties of in vitro model membranes as model cell membranes have been extensively studied with a variety of techniques, from classical thermodynamics to advanced modern microscopies. Here we review the nanomechanics of solid-supported lipid membranes with a focus in their phase behavior. Relevant information obtained by quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM) as complementary techniques in the nano/mesoscale interface is presented. Membrane morphological and mechanical characterization will be discussed in the framework of its phase behavior, phase transitions and coexistence, in simple and complex models, and upon the presence of cholesterol.
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Affiliation(s)
- Lorena Redondo-Morata
- Center for Infection and Immunity of Lille, INSERM U1019, CNRS UMR 8204, Lille, France
| | - Patricia Losada-Pérez
- Experimental Soft Matter and Thermal Physics (EST) Group, Department of Physics, Université Libre de Bruxelles, Brussels, Belgium
| | - Marina Inés Giannotti
- Biomedical Research Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain; Institut de Bioenginyeria de Catalunya (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain; Departament de Ciència de Materials i Química Física, Universitat de Barcelona, Barcelona, Spain.
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14
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Michel O, Pakhomov AG, Casciola M, Saczko J, Kulbacka J, Pakhomova ON. Electropermeabilization does not correlate with plasma membrane lipid oxidation. Bioelectrochemistry 2020; 132:107433. [DOI: 10.1016/j.bioelechem.2019.107433] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 11/20/2019] [Accepted: 11/22/2019] [Indexed: 12/24/2022]
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15
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Lee TH, Hall K, Aguilar MI. The Effect of Charge on Melittin-Induced Changes in Membrane Structure and Morphology. Aust J Chem 2020. [DOI: 10.1071/ch19500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The binding of melittin to a range of phospholipid bilayers was studied using dual polarisation interferometry and atomic force microscopy. The phospholipid model membranes included zwitterionic dimyristylphosphatidylcholine (DMPC), together with mixtures of DMPC/dimyristylphosphatidylglycerol (DMPG) and DMPC/DMPG/cholesterol. Melittin caused significant disruption on all bilayers, but differences in morphological changes during binding were different on each membrane. Overall, the results demonstrate that the process of membrane disruption follows distinct structural changes for different lipid mixtures irrespective of the strength of binding to the membrane surface.
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16
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Siddiquee AM, Hasan IY, Wei S, Langley D, Balaur E, Liu C, Lin J, Abbey B, Mechler A, Kou S. Visualization and measurement of the local absorption coefficients of single bilayer phospholipid membranes using scanning near-field optical microscopy. BIOMEDICAL OPTICS EXPRESS 2019; 10:6569-6579. [PMID: 31853417 PMCID: PMC6913387 DOI: 10.1364/boe.10.006569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/09/2019] [Accepted: 11/20/2019] [Indexed: 06/10/2023]
Abstract
Here we report the results of shear-mode thicknesses and absorption coefficient measurements made on neat membranes using scanning near-field optical microscopy (SNOM). Biomimic neat membranes composed of two different types of phoshpholipid molecules: 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2- dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) were found to exhibit different absorption coefficients under the SNOM. The localization of the lipids could be identified and correlated to the morphology of the membrane domains indicating that SNOM can be an effective and accurate approach for the label-free characterization of the structure-function relationships in cell membranes.
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Affiliation(s)
- Arif M Siddiquee
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Australia
| | - Imad Younus Hasan
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Victoria 3086, Australia
| | - Shibiao Wei
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Victoria 3086, Australia
- Centre for Translational Atomaterials, Faculty of Engineering, Science and Technology, Swinburne University of Technology, John Street, Hawthorn VIC 3122, Australia
| | - Daniel Langley
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Australia
| | - Eugeniu Balaur
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Australia
| | - Chen Liu
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Victoria 3086, Australia
| | - Jiao Lin
- School of Engineering, RMIT University, Melbourne, VIC 3001, Australia
| | - Brian Abbey
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Australia
| | - Adam Mechler
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Victoria 3086, Australia
| | - Shanshan Kou
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Victoria 3086, Australia
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Australia
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17
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18
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Bukiya AN, Dopico AM. Regulation of BK Channel Activity by Cholesterol and Its Derivatives. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1115:53-75. [DOI: 10.1007/978-3-030-04278-3_3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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19
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Cebecauer M, Amaro M, Jurkiewicz P, Sarmento MJ, Šachl R, Cwiklik L, Hof M. Membrane Lipid Nanodomains. Chem Rev 2018; 118:11259-11297. [PMID: 30362705 DOI: 10.1021/acs.chemrev.8b00322] [Citation(s) in RCA: 128] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Lipid membranes can spontaneously organize their components into domains of different sizes and properties. The organization of membrane lipids into nanodomains might potentially play a role in vital functions of cells and organisms. Model membranes represent attractive systems to study lipid nanodomains, which cannot be directly addressed in living cells with the currently available methods. This review summarizes the knowledge on lipid nanodomains in model membranes and exposes how their specific character contrasts with large-scale phase separation. The overview on lipid nanodomains in membranes composed of diverse lipids (e.g., zwitterionic and anionic glycerophospholipids, ceramides, glycosphingolipids) and cholesterol aims to evidence the impact of chemical, electrostatic, and geometric properties of lipids on nanodomain formation. Furthermore, the effects of curvature, asymmetry, and ions on membrane nanodomains are shown to be highly relevant aspects that may also modulate lipid nanodomains in cellular membranes. Potential mechanisms responsible for the formation and dynamics of nanodomains are discussed with support from available theories and computational studies. A brief description of current fluorescence techniques and analytical tools that enabled progress in lipid nanodomain studies is also included. Further directions are proposed to successfully extend this research to cells.
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Affiliation(s)
- Marek Cebecauer
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 3 , 18223 Prague 8 , Czech Republic
| | - Mariana Amaro
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 3 , 18223 Prague 8 , Czech Republic
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 3 , 18223 Prague 8 , Czech Republic
| | - Maria João Sarmento
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 3 , 18223 Prague 8 , Czech Republic
| | - Radek Šachl
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 3 , 18223 Prague 8 , Czech Republic
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 3 , 18223 Prague 8 , Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 3 , 18223 Prague 8 , Czech Republic
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20
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C R, Basu JK. Emergence of compositionally tunable nanoscale dynamical heterogeneity in model binary lipid biomembranes. SOFT MATTER 2017; 13:4598-4606. [PMID: 28604915 DOI: 10.1039/c7sm00581d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
While the existence of nanoscale dynamical heterogeneity in biological membranes has been suggested to act as an active functional platform for enabling various cellular processes like signal transduction and viral or bacterial entry, it has been extremely difficult to detect the existence of such domains. Model lipid bilayer membranes have been widely used to detect such dynamical heterogeneity in order to avoid complications arising from the compositional heterogeneity of cellular membranes. However, even in model biological membranes the issue of nanoscale lipid dynamics has remained controversial and unresolved due to the difficulty of detecting the existence of such dynamical heterogeneity on the scale of 10-300 nm. Here we report direct evidence of nanoscale lipid dynamical heterogeneity in model binary lipid bilayer membranes using a combination of super-resolution stimulated emission depletion (STED) microscopy and fluorescence correlation spectroscopy (FCS). We control the phase behavior of the lipid bilayers by varying their composition and discuss how this leads to the emergence of dynamical lipid domains on the scale of 80-150 nm, which is also dependent on the lipid phase in which such dynamics are observed. Notably, our work shows that the presence of cholesterol is not required for the existence of such domains even in fluid like bilayers, as has been widely believed, and specifies the minimal conditions required for the emergence of such dynamical heterogeneity in cellular membranes. Our work will thus not only be of great significance towards understanding the nanoscale dynamic organizing principles of cellular membranes but could also be useful in understanding the dynamics of related soft matter systems and nanoparticle-cell membrane interactions.
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Affiliation(s)
- Roobala C
- Department of Physics, Indian Institute of Science, Bangalore, 560 012, India.
| | - Jaydeep K Basu
- Department of Physics, Indian Institute of Science, Bangalore, 560 012, India.
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21
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Scaiano JC, Lanterna AE. Is Single-Molecule Fluorescence Spectroscopy Ready To Join the Organic Chemistry Toolkit? A Test Case Involving Click Chemistry. J Org Chem 2017; 82:5011-5019. [DOI: 10.1021/acs.joc.6b03010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Juan C. Scaiano
- Department of Chemistry and
Biomolecular Sciences and Centre for Catalysis Research and Innovation
(CCRI), University of Ottawa. 10 Marie Curie, Ottawa, ON K1N 6N5, Canada
| | - Anabel E. Lanterna
- Department of Chemistry and
Biomolecular Sciences and Centre for Catalysis Research and Innovation
(CCRI), University of Ottawa. 10 Marie Curie, Ottawa, ON K1N 6N5, Canada
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22
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Chen M, Balhara V, Jaimes Castillo AM, Balsevich J, Johnston LJ. Interaction of saponin 1688 with phase separated lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1263-1272. [PMID: 28389202 DOI: 10.1016/j.bbamem.2017.03.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 03/14/2017] [Accepted: 03/31/2017] [Indexed: 12/12/2022]
Abstract
Saponins are a diverse family of naturally occurring plant triterpene or steroid glycosides that have a wide range of biological activities. They have been shown to permeabilize membranes and in some cases membrane disruption has been hypothesized to involve saponin/cholesterol complexes. We have examined the interaction of steroidal saponin 1688-1 with lipid membranes that contain cholesterol and have a mixture of liquid-ordered (Lo) and liquid-disordered (Ld) phases as a model for lipid rafts in cellular membranes. A combination of atomic force microscopy (AFM) and fluorescence was used to probe the effect of saponin on the bilayer. The results demonstrate that saponin forms defects in the membrane and also leads to formation of small aggregates on the membrane surface. Although most of the membrane damage occurs in the liquid-disordered phase, fluorescence results demonstrate that saponin localizes in both ordered and disordered membrane phases, with a modest preference for the disordered regions. Similar effects are observed for both direct incorporation of saponin in the lipid mixture used to make vesicles/bilayers and for incubation of saponin with preformed bilayers. The results suggest that the initial sites of interaction are at the interface between the domains and surrounding disordered phase. The preference for saponin localization in the disordered phase may reflect the ease of penetration of saponin into a less ordered membrane, rather than the actual cholesterol concentration in the membrane. Dye leakage assays indicate that a high concentration of saponin is required for membrane permeabilization consistent with the supported lipid bilayer experiments.
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Affiliation(s)
- Maohui Chen
- Measurement Science and Standards, National Research Council Canada, Ottawa, ON K1A 0R6, Canada
| | - Vinod Balhara
- Measurement Science and Standards, National Research Council Canada, Ottawa, ON K1A 0R6, Canada
| | | | - John Balsevich
- Aquatic and Crop Resource Development, National Research Council Canada, Saskatoon, SK S7N 0W9, Canada
| | - Linda J Johnston
- Measurement Science and Standards, National Research Council Canada, Ottawa, ON K1A 0R6, Canada.
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23
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Mantil E, Crippin T, Ianoul A, Avis TJ. Experimental Parameters Leading to Optimal Bilayers for Total Internal Reflection Fluorescence Microscopy Visualization. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2017; 23:97-112. [PMID: 28228172 DOI: 10.1017/s1431927617000083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Supported lipid bilayer systems were evaluated following various experimental procedures in an effort to determine their appropriateness for visualization using total internal reflection fluorescence (TIRF) microscopy. The incorporation and distribution of Texas Red® 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (TR-DHPE) was studied when incorporated into bilayers of variable lipid composition using different forms of mechanical shearing. Results showed that 0.8 mol% TR-DHPE provides the most optimum TIRF images. At this concentration, a sufficient level of photostability can be achieved without an undesirable increase in TR-DHPE aggregates caused by excess probe molecules. Solutions composed of a 3:1 molar ratio of DOPC:DPPC with 0.8 mol% TR-DHPE produce bilayers that consistently display clear, distinct, rounded domains, whereas other lipid compositions did not. This optimum phase separation appears to be influenced by an increase in mechanical shearing during the vesicle formation process, when the lipid solutions were exposed to sonication and extrusion processes. The combination of a sonication and extrusion process also helped with eliminating the presence of TR-DHPE aggregates within the model membranes. It was also shown that bilayers formed on conditioned glass, placed on a slide, produced more highly detailed bilayers in which distinct lipid phase separation could be optimally visualized using TIRF microscopy.
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Affiliation(s)
- Elisabeth Mantil
- 1Department of Chemistry,Carleton University,1125 Colonel By Drive,Ottawa,ON K1S 5B6,Canada
| | - Trinda Crippin
- 2Department of Biology,Carleton University,1125 Colonel By Drive,Ottawa,ON K1S 5B6,Canada
| | - Anatoli Ianoul
- 1Department of Chemistry,Carleton University,1125 Colonel By Drive,Ottawa,ON K1S 5B6,Canada
| | - Tyler J Avis
- 1Department of Chemistry,Carleton University,1125 Colonel By Drive,Ottawa,ON K1S 5B6,Canada
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24
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Hasan IY, Mechler A. Nanoviscosity Measurements Revealing Domain Formation in Biomimetic Membranes. Anal Chem 2017; 89:1855-1862. [PMID: 28208292 DOI: 10.1021/acs.analchem.6b04256] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Partitioning of lipid molecules in biomimetic membranes is a model system for the study of naturally occurring domains, such as rafts, in biological membranes. The existence of nanometer scale membrane domains in binary lipid mixtures has been shown with microscopy methods; however, the nature of these domains has not been established unequivocally. A common notion is to ascribe domain separation to thermodynamic phase equilibria. However, characterizing thermodynamic phases of single bilayer membranes has not been possible due to their extreme dimensions: the size of the domains falls to the order of tens to hundreds of nanometers whereas the membrane thickness is only a few nanometers. Here, we present direct measurements of phase transitions in single bilayers of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)/1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) phospholipid mixtures using quartz crystal microbalance-based nanoviscosity measurements. Coexisting thermodynamic phases have been successfully identified, and a phase diagram was constructed for the single bilayer binary lipid system. It was demonstrated that domain separation only takes place in planar membranes, and thus, it is absent in liposomes and not detectable in calorimetric measurements on liposome suspensions. On the basis of energetic analysis, the main transition was identified as the breaking of van der Waals interactions between the acyl chains.
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Affiliation(s)
- Imad Younus Hasan
- La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria 3086, Australia
| | - Adam Mechler
- La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria 3086, Australia
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25
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Aybeke EN, Belliot G, Lemaire-Ewing S, Estienney M, Lacroute Y, Pothier P, Bourillot E, Lesniewska E. HS-AFM and SERS Analysis of Murine Norovirus Infection: Involvement of the Lipid Rafts. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1600918. [PMID: 28044439 DOI: 10.1002/smll.201600918] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 07/18/2016] [Indexed: 06/06/2023]
Abstract
Studies on human norovirus are severely hampered by the absence of a cell culture system until the discovery of murine norovirus (MNV). The cell membrane domains called lipid rafts have been defined as a port of entry for viruses. This study is conducted to investigate murine norovirus binding on the mouse leukemic monocyte macrophage cell line. Lipid raft related structures are extracted from cells by detergent treatment resulting detergent-resistant membrane (DRMs) domains. The real-time polymerase chain reaction technique is performed to detect the viral genome, thereby the MNV binding on the DRMs. The interactions between MNV and DRMs are investigated by high-speed atomic force microscopy (HS-AFM) combined with surface-enhanced Raman spectroscopy (SERS). The inoculation of the virus onto cells results in the aggregations of detergent-resistant membrane domains significantly. The characteristic Raman band of MNV is found in inoculated samples. To be sure that these results are originated from specific interactions between DRM and MNV, methyl-β-cyclo-dextrin (MβCD) is applied to disrupt lipid rafts. The MNV binding on DRMs is precluded by the MβCD treatment. The cholesterols chains are defined as a key factor in the interactions between norovirus and DRMs. The authors conclude that the MNV binding involves the presence of DRMs and cholesterol dependent.
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Affiliation(s)
- Ece N Aybeke
- ICB UMR CNRS 6303, University of Bourgogne Franche-Comte, Dijon, F-21000, France
| | - Gaël Belliot
- Laboratory of Virology, National Reference Center for Enteric Viruses, CHU F. Mitterrand, Dijon, F-21000, France
- AgroSup Dijon, PAM UMR A 02.102, University of Bourgogne Franche-Comte, Dijon, F-21000, France
| | | | - Marie Estienney
- Laboratory of Virology, National Reference Center for Enteric Viruses, CHU F. Mitterrand, Dijon, F-21000, France
- AgroSup Dijon, PAM UMR A 02.102, University of Bourgogne Franche-Comte, Dijon, F-21000, France
| | - Yvon Lacroute
- ICB UMR CNRS 6303, University of Bourgogne Franche-Comte, Dijon, F-21000, France
| | - Pierre Pothier
- Laboratory of Virology, National Reference Center for Enteric Viruses, CHU F. Mitterrand, Dijon, F-21000, France
- AgroSup Dijon, PAM UMR A 02.102, University of Bourgogne Franche-Comte, Dijon, F-21000, France
| | - Eric Bourillot
- ICB UMR CNRS 6303, University of Bourgogne Franche-Comte, Dijon, F-21000, France
| | - Eric Lesniewska
- ICB UMR CNRS 6303, University of Bourgogne Franche-Comte, Dijon, F-21000, France
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26
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Hasan IY, Mechler A. Analytical approaches to study domain formation in biomimetic membranes. Analyst 2017; 142:3062-3078. [PMID: 28758651 DOI: 10.1039/c7an01038a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Novel characterization methods open new horizons in the study of membrane mixtures.
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Affiliation(s)
- Imad Younus Hasan
- La Trobe Institute for Molecular Science
- La Trobe University
- Melbourne
- Australia
| | - Adam Mechler
- La Trobe Institute for Molecular Science
- La Trobe University
- Melbourne
- Australia
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27
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Gräb O, Abacilar M, Daus F, Geyer A, Steinem C. 3D-Membrane Stacks on Supported Membranes Composed of Diatom Lipids Induced by Long-Chain Polyamines. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10144-10152. [PMID: 27603681 DOI: 10.1021/acs.langmuir.6b02575] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Long-chain polyamines (LCPAs) are intimately involved in the biomineralization process of diatoms taking place in silica deposition vesicles being acidic compartments surrounded by a lipid bilayer. Here, we addressed the question whether and how LCPAs interact with lipid membranes composed of glycerophospholipids and glyceroglycolipids mimicking the membranes of diatoms and higher plants. Solid supported lipid bilayers and monolayers containing the three major components that are unique in diatoms and higher plants, i.e., monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), and sulfoquinovosyldiacylglycerol (SQDG), were prepared by spreading small unilamellar vesicles. The integrity of the membranes was investigated by fluorescence microscopy and atomic force microscopy showing continuous flat bilayers and monolayers with small protrusions on top of the membrane. The addition of a synthetic polyamine composed of 13 amine groups separated by a propyl spacer (C3N13) results in flat but three-dimensional membrane stacks within minutes. The membrane stacks are connected with the underlying membrane as verified by fluorescence recovery after photobleaching experiments. Membrane stack formation was found to be independent of the lipid composition; i.e., neither glyceroglycolipids nor negatively charged lipids were required. However, the formation process was strongly dependent on the chain length of the polyamine. Whereas short polyamines such as the naturally occurring spermidine, spermine, and the synthetic polyamines C3N4 and C3N5 do not induce stack formation, those containing seven and more amine groups (C3N7, C3N13, and C3N18) do form membrane stacks. The observed stack formation might have implications for the stability and expansion of the silica deposition vesicle during valve and girdle band formation in diatoms.
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Affiliation(s)
- Oliver Gräb
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstr. 2, 37077 Göttingen, Germany
| | - Maryna Abacilar
- Faculty of Chemistry, Philipps-University Marburg , Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Fabian Daus
- Faculty of Chemistry, Philipps-University Marburg , Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Armin Geyer
- Faculty of Chemistry, Philipps-University Marburg , Hans-Meerwein-Str. 4, 35032 Marburg, Germany
| | - Claudia Steinem
- Institute of Organic and Biomolecular Chemistry, University of Göttingen , Tammannstr. 2, 37077 Göttingen, Germany
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28
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Beltramo PJ, Vermant J. Simple Optical Imaging of Nanoscale Features in Free-Standing Films. ACS OMEGA 2016; 1:363-370. [PMID: 30023480 PMCID: PMC6044614 DOI: 10.1021/acsomega.6b00125] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 08/31/2016] [Indexed: 05/19/2023]
Abstract
Measuring thicknesses in thin films with high spatial and temporal resolution is of prime importance for understanding the structure and dynamics in thin films and membranes. In the present work, we introduce fluorescence-interferometry, a method that combines standard reflected light thin film interferometry with simultaneous fluorescence measurements. We apply this method to the thinning dynamics and phase separation in free-standing inverse phospholipid bilayer films. The measurements were carried out using a standard fluorescence microscope using multichannel imaging and yielded subnanometer resolution, which is applied to optically measure the discrete thickness variations across phase-separated membranes.
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29
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Porta A, Petrone AM, Morello S, Granata I, Rizzo F, Memoli D, Weisz A, Maresca B. Design and expression of peptides with antimicrobial activity againstSalmonellatyphimurium. Cell Microbiol 2016; 19. [DOI: 10.1111/cmi.12645] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/06/2016] [Indexed: 02/02/2023]
Affiliation(s)
- Amalia Porta
- Department of Pharmacy; University of Salerno; Fisciano (SA) Italy
| | - Anna Maria Petrone
- Department of Pharmacy; University of Salerno; Fisciano (SA) Italy
- PhD Program in Drug Discovery and Development; University of Salerno; Fisciano SA Italy
| | - Silvana Morello
- Department of Pharmacy; University of Salerno; Fisciano (SA) Italy
| | - Ilaria Granata
- Department of Pharmacy; University of Salerno; Fisciano (SA) Italy
| | - Francesca Rizzo
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery; University of Salerno; Baronissi SA Italy
| | - Domenico Memoli
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery; University of Salerno; Baronissi SA Italy
| | - Alessandro Weisz
- Laboratory of Molecular Medicine and Genomics, Department of Medicine and Surgery; University of Salerno; Baronissi SA Italy
| | - Bruno Maresca
- Department of Pharmacy; University of Salerno; Fisciano (SA) Italy
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30
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Jiang YW, Guo HY, Chen Z, Yu ZW, Wang Z, Wu FG. In Situ Visualization of Lipid Raft Domains by Fluorescent Glycol Chitosan Derivatives. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:6739-6745. [PMID: 27276053 DOI: 10.1021/acs.langmuir.6b00193] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Lipid rafts are highly ordered small microdomains mainly composed of glycosphingolipids, cholesterol, and protein receptors. Optically distinguishing lipid raft domains in cell membranes would greatly facilitate the investigations on the structure and dynamics of raft-related cellular behaviors, such as signal transduction, membrane transport (endocytosis), adhesion, and motility. However, current strategies about the visualization of lipid raft domains usually suffer from the low biocompatibility of the probes, invasive detection, or ex situ observation. At the same time, naturally derived biomacromolecules have been extensively used in biomedical field and their interaction with cells remains a long-standing topic since it is closely related to various fundamental studies and potential applications. Herein, noninvasive visualization of lipid raft domains in model lipid bilayers (supported lipid bilayers and giant unilamellar vesicles) and live cells was successfully realized in situ using fluorescent biomacromolecules: the fluorescein isothiocyanate (FITC)-labeled glycol chitosan molecules. We found that the lipid raft domains in model or real membranes could be specifically stained by the FITC-labeled glycol chitosan molecules, which could be attributed to the electrostatic attractive interaction and/or hydrophobic interaction between the probes and the lipid raft domains. Since the FITC-labeled glycol chitosan molecules do not need to completely insert into the lipid bilayer and will not disturb the organization of lipids, they can more accurately visualize the raft domains as compared with other fluorescent dyes that need to be premixed with the various lipid molecules prior to the fabrication of model membranes. Furthermore, the FITC-labeled glycol chitosan molecules were found to be able to resist cellular internalization and could successfully visualize rafts in live cells. The present work provides a new way to achieve the imaging of lipid rafts and also sheds new light on the interaction between biomacromolecules and lipid membranes.
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Affiliation(s)
- Yao-Wen Jiang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, P. R. China
| | - Hao-Yue Guo
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, P. R. China
| | - Zhan Chen
- Department of Chemistry, University of Michigan , 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Zhi-Wu Yu
- Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University , Beijing 100084, P. R. China
| | - Zhifei Wang
- School of Chemistry and Chemical Engineering, Southeast University , Nanjing 211189, P. R. China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, P. R. China
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31
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Samant P, Chen J, Xiang L. Characterization of the temperature rise in a single cell during photoacoustic tomography at the nanoscale. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:75009. [PMID: 27405264 DOI: 10.1117/1.jbo.21.7.075009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/21/2016] [Indexed: 06/06/2023]
Abstract
We are developing a label-free nanoscale photoacoustic tomography (nPAT) for imaging a single living cell. nPAT uses a laser-induced acoustic pulse to generate a nanometer-scale image. The primary motivation behind this imaging technique is the imaging of biological cells in the context of diagnosis without fluorescent tagging. During this procedure, thermal damage due to the laser pulse is a potential risk that may damage the cells. A physical model is built to estimate the temperature rise and thermal relaxation during the imaging procedure. Through simulations using finite element methods, two lasers (532 nm at 5 ps pulse duration and 830 nm at 0.2 ps pulse duration) were simulated for imaging red blood cells (RBCs). We demonstrate that a single 5-ps pulse laser with a 400-Hz repetition rate will generate a steady state temperature rise of less than a Kelvin on the surface of the RBCs. All the simulation results show that there is no significant temperature rise in an RBC in either single pulse or multiple pulse illumination with a 532-nm laser with 219 W fluence. Therefore, our simulation results demonstrate the thermal safety of an nPAT system. The photoacoustic signal generated by this laser is on the order of 2.5 kPa, so it should still be large enough to generate high-resolution images with nPAT. Frequency analysis of this signal shows a peak at 1.47 GHz, with frequencies as high as 3.5 GHz still being present in the spectrum. We believe that nPAT will open an avenue for disease diagnosis and cell biology studies at the nanometer-level.
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Bourlieu C, Paboeuf G, Chever S, Pezennec S, Cavalier JF, Guyomarc’h F, Deglaire A, Bouhallab S, Dupont D, Carrière F, Vié V. Adsorption of gastric lipase onto multicomponent model lipid monolayers with phase separation. Colloids Surf B Biointerfaces 2016; 143:97-106. [DOI: 10.1016/j.colsurfb.2016.03.032] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 03/07/2016] [Accepted: 03/10/2016] [Indexed: 01/17/2023]
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Hasan IY, Mechler A. Cholesterol Rich Domains Identified in Unilamellar Supported Biomimetic Membranes via Nano-Viscosity Measurements. Anal Chem 2016; 88:5037-41. [PMID: 27137411 DOI: 10.1021/acs.analchem.6b01045] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding the distribution of cholesterol in phospholipid membranes is of key importance in membrane biophysics, primarily since cholesterol enriched regions, rafts, are known to play a special role in protein function. In this work, quartz crystal microbalance with dissipation (QCM)-based viscosity measurements were used to study cholesterol-induced domain formation in partially suspended single bilayer membranes. 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and its mixtures with different amounts of cholesterol were studied. QCM temperature ramping experiments identified domains of different phase transition temperatures in the mixed membranes. The phase transition of DMPC shifted from 23.4 °C toward lower temperatures with increasing cholesterol content. A second, continuous but much broader, transition peak has been observed for the DMPC: cholesterol mixtures suggest that a separate cholesterol rich domain coexists with the DMPC rich domain. Importantly, the sharp DMC phase transition peak gradually diminished and eventually disappeared over 15% cholesterol content, suggesting that the cholesterol rich domain has a definite stoichiometry and once this cholesterol concentration is reached the DMPC-rich domain disappears. DSC control experiments do not show the second domain, suggesting that the phase separation only happens in nontensioned (flat) membranes.
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Affiliation(s)
- Imad Younus Hasan
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria 3086, Australia
| | - Adam Mechler
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria 3086, Australia
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Matsubara T, Shibata R, Sato T. Binding of Hemagglutinin and Influenza Virus to a Peptide-Conjugated Lipid Membrane. Front Microbiol 2016; 7:468. [PMID: 27092124 PMCID: PMC4823272 DOI: 10.3389/fmicb.2016.00468] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 03/21/2016] [Indexed: 01/09/2023] Open
Abstract
Hemagglutinin (HA) plays an important role in the first step of influenza virus (IFV) infection because it initiates the binding of the virus to the sialylgalactose linkages of the receptors on the host cells. We herein demonstrate that a HA-binding peptide immobilized on a solid support is available to bind to HA and IFV. We previously obtained a HA-binding pentapeptide (Ala-Arg-Leu-Pro-Arg), which was identified by phage-display selection against HAs from random peptide libraries. This peptide binds to the receptor-binding site of HA by mimicking sialic acid. A peptide-conjugated lipid (pep-PE) was chemically synthesized from the peptide and a saturated phospholipid. A lipid bilayer composed of pep-PE and an unsaturated phospholipid (DOPC) was immobilized on a mica plate; and the interaction between HA and the pep-PE/DOPC membrane was investigated using atomic force microscopy. The binding of IFV to the pep-PE/DOPC membrane was detected by an enzyme-linked immunosorbent assay and real-time reverse transcription PCR. Our results indicate that peptide-conjugated lipids are a useful molecular device for the detection of HA and IFV.
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Affiliation(s)
- Teruhiko Matsubara
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University Yokohama, Japan
| | - Rabi Shibata
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University Yokohama, Japan
| | - Toshinori Sato
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University Yokohama, Japan
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Niko Y, Didier P, Mely Y, Konishi GI, Klymchenko AS. Bright and photostable push-pull pyrene dye visualizes lipid order variation between plasma and intracellular membranes. Sci Rep 2016; 6:18870. [PMID: 26750324 PMCID: PMC4707542 DOI: 10.1038/srep18870] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/30/2015] [Indexed: 12/23/2022] Open
Abstract
Imaging lipid organization in cell membranes requires advanced fluorescent probes. Here, we show that a recently synthesized push-pull pyrene (PA), similarly to popular probe Laurdan, changes the emission maximum as a function of lipid order, but outperforms it by spectroscopic properties. In addition to red-shifted absorption compatible with common 405 nm diode laser, PA shows higher brightness and much higher photostability than Laurdan in apolar membrane environments. Moreover, PA is compatible with two-photon excitation at wavelengths >800 nm, which was successfully used for ratiometric imaging of coexisting liquid ordered and disordered phases in giant unilamellar vesicles. Fluorescence confocal microscopy in Hela cells revealed that PA efficiently stains the plasma membrane and the intracellular membranes at >20-fold lower concentrations, as compared to Laurdan. Finally, ratiometric imaging using PA reveals variation of lipid order within different cellular compartments: plasma membranes are close to liquid ordered phase of model membranes composed of sphingomyelin and cholesterol, while intracellular membranes are much less ordered, matching well membranes composed of unsaturated phospholipids without cholesterol. These differences in the lipid order were confirmed by fluorescence lifetime imaging (FLIM) at the blue edge of PA emission band. PA probe constitutes thus a new powerful tool for biomembrane research.
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Affiliation(s)
- Yosuke Niko
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology, 2-12-1-H-134 O-okayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Pascal Didier
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France
| | - Yves Mely
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France
| | - Gen-ichi Konishi
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology, 2-12-1-H-134 O-okayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Andrey S. Klymchenko
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France
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Musgrove A, Bizzotto D. Potential Controls the Interaction of Liposomes with Octadecanol-Modified Au Electrodes: An in Situ AFM Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:12797-12806. [PMID: 26528884 DOI: 10.1021/acs.langmuir.5b03605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The formation of supported lipid bilayers using liposomes requires interaction with the solid surface, rupture of the liposome, and spreading to cover the surface with a lipid bilayer. This can result in a less-than-uniform coating of the solid surface. Presented is a method that uses the electrochemical poration of an adsorbed lipid-like layer on a Au electrode to control the interaction of 100 nm DOPC liposomes. An octadecanol-coated Au-on-mica surface was imaged using tapping-mode AFM during the application of potential in the presence or absence of liposomes. When the substrate potential was made negative enough, defects formed in the adsorbed layer and new taller features were observed. More features were observed and existing features increased in size with time spent at this negative poration potential. The new features were 1.8-2.0 nm higher than the octadecanol-coated gold surface, half the thickness of a DOPC bilayer. These features were not observed in the absence of liposomes when undergoing the same potential perturbation. In the presence of liposomes, the application of a poration potential was needed to initiate the formation of these taller features. Once the applied potential was removed, the features stopped growing and no new regions were observed. The size of these new regions was consistent with the footprint of a flattened 100 nm liposome. It is speculated that the DOPC liposomes were able to interact with the defects and became soluble in the octadecanol, creating a taller region that was limited in size to the liposome that adsorbed and became incorporated. This AFM study confirms previous in situ fluorescence measurements of the same system and illustrates the use of a potential perturbation to control the formation of these regions of increased DOPC content.
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Affiliation(s)
- Amanda Musgrove
- AMPEL, Department of Chemistry, University of British Columbia , Vancouver, British Columbia V6T 1Z4, Canada
| | - Dan Bizzotto
- AMPEL, Department of Chemistry, University of British Columbia , Vancouver, British Columbia V6T 1Z4, Canada
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Ho CS, Khadka NK, Pan J. Sub-ten-nanometer heterogeneity of solid supported lipid membranes determined by solution atomic force microscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:181-8. [PMID: 26551323 DOI: 10.1016/j.bbamem.2015.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 10/19/2015] [Accepted: 11/05/2015] [Indexed: 12/18/2022]
Abstract
Visually detecting nanoscopic structures in lipid membranes is important for elucidating lipid-lipid interactions, which are suggested to play a role in mediating membrane rafts. We use solution atomic force microscopy (AFM) to study lateral and normal organization in multicomponent lipid membranes supported by mica substrate. Nanoscopic heterogeneity is observed in a three-component system composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/brain-sphingomyelin (bSM)/cholesterol (Chol). We find sub-ten-nanometer correlation lengths that are used to describe membrane lateral organization. In addition, we find that the correlation length is independent on cholesterol concentration, while the height fluctuation (variation) is not. To explore the mechanism that controls the size of membrane heterogeneity, we extend our study to a four-component system composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/POPC/bSM/Chol. By systematically adjusting the relative amount of DOPC and POPC, we obtain macroscopic-to-nanoscopic size transition of membrane heterogeneity. In contrast to the results from vesicle based fluorescence microscopy, we find that the structural transition is continuous both in the lateral and normal directions. We compare our nanoscopic structures to two theoretical models, and find that both the critical fluctuations and the nanodomain models are not sufficient to account for our solution AFM data. Finally, we propose a nanoheterogeneity model that could serve as the organization principle of the observed nanoscopic structures in multicomponent lipid membranes.
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Affiliation(s)
- Chian Sing Ho
- Department of Physics, University of South Florida, Tampa, FL 33620, USA
| | - Nawal K Khadka
- Department of Physics, University of South Florida, Tampa, FL 33620, USA
| | - Jianjun Pan
- Department of Physics, University of South Florida, Tampa, FL 33620, USA.
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Nickels JD, Smith JC, Cheng X. Lateral organization, bilayer asymmetry, and inter-leaflet coupling of biological membranes. Chem Phys Lipids 2015; 192:87-99. [DOI: 10.1016/j.chemphyslip.2015.07.012] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/20/2015] [Accepted: 07/25/2015] [Indexed: 11/28/2022]
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Atomic Force Microscopy and Electrochemical Studies of Melittin Action on Lipid Bilayers Supported on Gold Electrodes. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2014.10.039] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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40
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Sphingomyelin distribution in lipid rafts of artificial monolayer membranes visualized by Raman microscopy. Proc Natl Acad Sci U S A 2015; 112:4558-63. [PMID: 25825736 DOI: 10.1073/pnas.1418088112] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sphingomyelin (SM) and cholesterol (chol)-rich domains in cell membranes, called lipid rafts, are thought to have important biological functions related to membrane signaling and protein trafficking. To visualize the distribution of SM in lipid rafts by means of Raman microscopy, we designed and synthesized an SM analog tagged with a Raman-active diyne moiety (diyne-SM). Diyne-SM showed a strong peak in a Raman silent region that is free of interference from intrinsic vibrational modes of lipids and did not appear to alter the properties of SM-containing monolayers. Therefore, we used Raman microscopy to directly visualize the distribution of diyne-SM in raft-mimicking domains formed in SM/dioleoylphosphatidylcholine/chol ternary monolayers. Raman images visualized a heterogeneous distribution of diyne-SM, which showed marked variation, even within a single ordered domain. Specifically, diyne-SM was enriched in the central area of raft domains compared with the peripheral area. These results seem incompatible with the generally accepted raft model, in which the raft and nonraft phases show a clear biphasic separation. One of the possible reasons is that gradual changes of SM concentration occur between SM-rich and -poor regions to minimize hydrophobic mismatch. We believe that our technique of hyperspectral Raman imaging of a single lipid monolayer opens the door to quantitative analysis of lipid membranes by providing both chemical information and spatial distribution with high (diffraction-limited) spatial resolution.
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Ngo AT, Jakubek ZJ, Lu Z, Joós B, Morris CE, Johnston LJ. Membrane order parameters for interdigitated lipid bilayers measured via polarized total-internal-reflection fluorescence microscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2861-9. [PMID: 25073072 DOI: 10.1016/j.bbamem.2014.07.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 07/03/2014] [Accepted: 07/21/2014] [Indexed: 12/25/2022]
Abstract
Incorporating ethanol in lipid membranes leads to changes in bilayer structure, including the formation of an interdigitated phase. We have used polarized total-internal-reflection fluorescence microscopy (pTIRFM) to measure the order parameter for Texas Red DHPE incorporated in the ethanol-induced interdigitated phase (LβI) formed from ternary lipid mixtures comprising dioleoylphosphatidylcholine, cholesterol and egg sphingomyelin or dipalmitoylphosphatidylcholine. These lipid mixtures have 3 co-existing phases in the presence of ethanol: liquid-ordered, liquid-disordered and LβI. pTIRFM using Texas Red DHPE shows a reversal in fluorescence contrast between the LβI phase and the surrounding disordered phase with changes in the polarization angle. The contrast reversal is due to changes in the orientation of the dye, and provides a rapid method to identify the LβI phase. The measured order parameters for the LβI phase are consistent with a highly ordered membrane environment, similar to a gel phase. An acyl-chain labeled BODIPY-FL-PC was also tested for pTIRFM studies of ethanol-treated bilayers; however, this probe is less useful since the order parameters of the interdigitated phase are consistent with orientations that are close to random, either due to local membrane disorder or to a mixture of extended and looping conformations in which the fluorophore is localized in the polar headgroup region of the bilayer. In summary, we demonstrate that order parameter measurements via pTIRFM using Texas Red-DHPE can rapidly identify the interdigitated phase in supported bilayers. We anticipate that this technique will aid further research in the effects of alcohols and other additives on membranes.
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Affiliation(s)
- An T Ngo
- Measurement Science and Standards, National Research Council Canada, Ottawa, ON K1A 0R6, Canada; Department of Physics, University of Ottawa Ottawa, ON K1N 6N5, Canada
| | - Zygmunt J Jakubek
- Measurement Science and Standards, National Research Council Canada, Ottawa, ON K1A 0R6, Canada
| | - Zhengfang Lu
- Measurement Science and Standards, National Research Council Canada, Ottawa, ON K1A 0R6, Canada
| | - Béla Joós
- Department of Physics, University of Ottawa Ottawa, ON K1N 6N5, Canada
| | | | - Linda J Johnston
- Measurement Science and Standards, National Research Council Canada, Ottawa, ON K1A 0R6, Canada.
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Lü J, Yang J, Dong M, Sahin O. Nanomechanical spectroscopy of synthetic and biological membranes. NANOSCALE 2014; 6:7604-8. [PMID: 24895687 DOI: 10.1039/c3nr02643d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We report that atomic force microscopy based high-speed nanomechanical analysis can identify components of complex heterogeneous synthetic and biological membranes from the measured spectrum of nanomechanical properties. We have investigated phase separated ternary lipid bilayers and purple membranes of Halobacterium salinarum. The nanomechanical spectra recorded on these samples identify all membrane components, some of which are difficult to resolve in conventional phase images. This non-destructive approach can aid the design of synthetic lipid bilayers and studies lateral organization of complex heterogeneous cellular membranes.
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Affiliation(s)
- Junhong Lü
- The Rowland Institute at Harvard, Harvard University, Cambridge, MA, USA
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Pomorski TG, Nylander T, Cárdenas M. Model cell membranes: discerning lipid and protein contributions in shaping the cell. Adv Colloid Interface Sci 2014; 205:207-20. [PMID: 24268587 DOI: 10.1016/j.cis.2013.10.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 10/24/2013] [Accepted: 10/24/2013] [Indexed: 01/01/2023]
Abstract
The high complexity of biological membranes has motivated the development and application of a wide range of model membrane systems to study biochemical and biophysical aspects of membranes in situ under well defined conditions. The aim is to provide fundamental understanding of processes controlled by membrane structure, permeability and curvature as well as membrane proteins by using a wide range of biochemical, biophysical and microscopic techniques. This review gives an overview of some currently used model biomembrane systems. We will also discuss some key membrane protein properties that are relevant for protein-membrane interactions in terms of protein structure and how it is affected by membrane composition, phase behavior and curvature.
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Affiliation(s)
- Thomas Günther Pomorski
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark
| | - Tommy Nylander
- Department of Chemistry, Division of Physical Chemistry, Lund University, Gettingevägen 60, SE-22100 Lund, Sweden
| | - Marité Cárdenas
- Department of Chemistry/Nano-Science Center, University of Copenhagen, DK-2100 Copenhagen, Denmark.
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Ramirez DMC, Jakubek ZJ, Lu Z, Ogilvie WW, Johnston LJ. Changes in order parameters associated with ceramide-mediated membrane reorganization measured using pTIRFM. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:15907-15918. [PMID: 24308875 DOI: 10.1021/la403585v] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The enzymatic generation of ceramide has significant effects on the biophysical properties of lipid bilayers and can lead to the extensive reorganization of cell membranes. We have synthesized and characterized a headgroup-labeled fluorescent lipid probe (NBD-ceramide, NBD-Cer) and demonstrated that it can be used for polarized total internal reflection fluorescence microscopy experiments to probe changes in membrane order that result from ceramide incorporation. NBD-Cer measures significantly higher order parameters for the liquid-ordered (Lo) domains ([P2] = 0.40 ± 0.03) than for the liquid-disordered phase (Ld, fluid, [P2] = 0.22 ± 0.02) of phase-separated bilayers prepared from egg sphingomyelin, dioleolyphosphatidylcholine, and cholesterol mixtures. The probe also responds to changes in packing induced by the direct incorporation of ceramide or the variation in the ionic strength of the aqueous medium. Order parameter maps obtained after enzyme treatment of bilayers with coexisting Lo and Ld phases show two distinct types of behavior. In regions of high enzyme activity, the initial Lo/Ld domains are replaced by large, dark features that have high membrane order corroborating previous hypotheses that these are ceramide-enriched regions of the membrane. In areas of low enzyme activity, the size and shape of the Lo domains are conserved, but there is an increase in the order parameter for the initial Ld phase ([P2] = 0.30 ± 0.01). This is attributed to the incorporation of ceramide in the Lo domains with the concomitant expulsion of cholesterol into the surrounding fluid phase, increasing its order parameter.
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Affiliation(s)
- Daniel M Carter Ramirez
- Measurement Science and Standards, National Research Council of Canada , Ottawa, Ontario K1A 0R6, Canada
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Klymchenko AS, Kreder R. Fluorescent probes for lipid rafts: from model membranes to living cells. ACTA ACUST UNITED AC 2013; 21:97-113. [PMID: 24361047 DOI: 10.1016/j.chembiol.2013.11.009] [Citation(s) in RCA: 335] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/22/2013] [Accepted: 11/04/2013] [Indexed: 01/10/2023]
Abstract
Membrane microdomains (rafts) remain one of the controversial issues in biophysics. Fluorescent molecular probes, which make these lipid nanostructures visible through optical techniques, are one of the tools currently used to study lipid rafts. The most common are lipophilic fluorescent probes that partition specifically into liquid ordered or liquid disordered phase. Their partition depends on the lipid composition of a given phase, which complicates their use in cellular membranes. A second class of probes is based on environment-sensitive dyes, which partition into both phases, but stain them by different fluorescence color, intensity, or lifetime. These probes can directly address the properties of each separate phase, but their cellular applications are still limited. The present review focuses on summarizing the current state in the field of developing and applying fluorescent molecular probes to study lipid rafts. We highlight an urgent need to develop new probes, specifically adapted for cell plasma membranes and compatible with modern fluorescence microscopy techniques to push the understanding of membrane microdomains forward.
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Affiliation(s)
- Andrey S Klymchenko
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH, France.
| | - Rémy Kreder
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH, France
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46
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Monserrate A, Casado S, Flors C. Correlative Atomic Force Microscopy and Localization-Based Super-Resolution Microscopy: Revealing Labelling and Image Reconstruction Artefacts. Chemphyschem 2013; 15:647-50. [DOI: 10.1002/cphc.201300853] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Indexed: 11/10/2022]
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47
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Motegi T, Nabika H, Murakoshi K. Single-molecule observations for determining the orientation and diffusivity of dye molecules in lipid bilayers. Phys Chem Chem Phys 2013; 15:12895-902. [PMID: 23812281 DOI: 10.1039/c3cp51585k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular orientation and diffusion of dye molecules in artificial lipid bilayers were observed using total internal reflection fluorescence microscopy. An artificial lipid bilayer composed of a ternary lipid mixture of 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), and cholesterol was used. The molecular orientation, which was obtained through defocused imaging, clarified the microscopic features, including cholesterol-induced changes in the local packing structure. Diffusion analysis gave insights into the macroscopic aspects of phase distribution in the heterogeneous bilayer system. Combining these two independent investigations, we revealed the effect of cholesterol addition on microscopic local packing and macroscopic phase structures. Our observations showed a transition from a DLPC-network-like structure to a DPPC-network-like structure upon the addition of cholesterol, which was not evident from previous domain shape observations. The present single-molecule observations yielded the actual phase structure that controls the motion of molecules in the membrane. The results imply that the orientation and diffusivity of molecules offer useful information regarding the phase distribution, which may be hindered by the apparent phase structure in a heterogeneous lipid bilayer that contains cholesterol.
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Affiliation(s)
- Toshinori Motegi
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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48
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Lima LMC, Giannotti MI, Redondo-Morata L, Vale MLC, Marques EF, Sanz F. Morphological and nanomechanical behavior of supported lipid bilayers on addition of cationic surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:9352-61. [PMID: 23782267 DOI: 10.1021/la400067n] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The addition of surfactants to lipid bilayers is important for the modulation of lipid bilayer properties (e.g., in protein reconstitution and development of nonviral gene delivery vehicles) and to provide insight on the properties of natural biomembranes. In this work, the thermal behavior, organization, and nanomechanical stability of model cationic lipid-surfactant bilayers have been investigated. Two different cationic surfactants, hexadecyltrimethylammonium bromide (CTAB) and a novel derivative of the amino acid serine (Ser16TFAc), have been added (up to 50 mol %) to both liposomes and supported lipid bilayers (SLBs) composed by the zwitterionic phospholipid DPPC. The thermal phase behavior of mixed liposomes has been probed by differential scanning calorimetry (DSC), and the morphology and nanomechanical properties of mixed SLBs by atomic force microscopy-based force spectroscopy (AFM-FS). Although DSC thermograms show different results for the two mixed liposomes, when both are deposited on mica substrates similar trends on the morphology and the mechanical response of the lipid-surfactant bilayers are observed. DSC thermograms indicate microdomain formation in both systems, but while CTAB decreases the degree of organization on the liposome bilayer, Ser16TFAc ultimately induces the opposite effect. Regarding the AFM-FS studies, they show that microphase segregation occurs for these systems and that the effect is dependent on the surfactant content. In both SLB systems, different microdomains characterized by their height and breakthrough force Fb are formed. The molecular organization and composition is critically discussed in the light of our experimental results and literature data on similar lipid-surfactant systems.
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Affiliation(s)
- Lia M C Lima
- Centro de Investigação em Química, Department of Chemistry and Biochemistry, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
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Biological functions of sphingomyelins. Prog Lipid Res 2013; 52:424-37. [PMID: 23684760 DOI: 10.1016/j.plipres.2013.05.001] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/12/2013] [Accepted: 05/02/2013] [Indexed: 12/14/2022]
Abstract
Sphingomyelin (SM) is a dominant sphingolipid in membranes of mammalian cells and this lipid class is specifically enriched in the plasma membrane, the endocytic recycling compartment, and the trans Golgi network. The distribution of SM and cholesterol among cellular compartments correlate. Sphingolipids have extensive hydrogen-bonding capabilities which together with their saturated nature facilitate the formation of sphingolipid and SM-enriched lateral domains in membranes. Cholesterol prefers to interact with SMs and this interaction has many important functional consequences. In this review, the synthesis, regulation, and intracellular distribution of SMs are discussed. The many direct roles played by membrane SM in various cellular functions and processes will also be discussed. These include involvement in the regulation of endocytosis and receptor-mediated ligand uptake, in ion channel and G-protein coupled receptor function, in protein sorting, and functioning as receptor molecules for various bacterial toxins, and for non-bacterial pore-forming toxins. SM is also an important constituent of the eye lens membrane, and is believed to participate in the regulation of various nuclear functions. SM is an independent risk factor in the development of cardiovascular disease, and new studies have shed light on possible mechanism behind its role in atherogenesis.
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Matsubara T, Iijima K, Yamamoto N, Yanagisawa K, Sato T. Density of GM1 in nanoclusters is a critical factor in the formation of a spherical assembly of amyloid β-protein on synaptic plasma membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:2258-2264. [PMID: 23294326 DOI: 10.1021/la3038999] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The deposition of amyloid β-protein (Aβ) is a pathological hallmark of Alzheimer's disease (AD). We previously found that the ganglioside-enriched microdomains (ganglioside clusters) in presynaptic neuronal membranes play a key role in the initiation of the Aβ assembly process. However, not all ganglioside clusters accelerate Aβ assembly. In the present study, we directly observed a spherical Aβ in an atomic force microscopic study on the morphology of a reconstituted lipid bilayer composed of lipids that were extracted from a detergent-resistant membrane microdomain (DRM) fraction of synaptosomes prepared from aged mouse brain. The Aβ assembly was generated on a distinctive GM1 domain, which was characterized as the Aβ-sensitive ganglioside nanocluster (ASIGN). By using an artificial GM1 cluster-binding peptide, ASIGN was found to have a high density of GM1; therefore, there would be a critical density of GM1 in nanoclusters to induce Aβ binding and assembly. These results suggest that ganglioside-bound Aβ (GAβ), which acts as an endogenous seed for Aβ fibril formation in AD brains, is generated on ASIGN on synaptosomal membranes.
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Affiliation(s)
- Teruhiko Matsubara
- Department of Biosciences and Informatics, Keio University, Kouhoku-ku, Yokohama, Japan
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