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Sunami T, Caschera F, Morita Y, Toyota T, Nishimura K, Matsuura T, Suzuki H, Hanczyc MM, Yomo T. Detection of association and fusion of giant vesicles using a fluorescence-activated cell sorter. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:15098-15103. [PMID: 20822108 DOI: 10.1021/la102689v] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We have developed a method to evaluate the fusion process of giant vesicles using a fluorescence-activated cell sorter (FACS). Three fluorescent markers and FACS technology were used to evaluate the extent of association and fusion of giant vesicles. Two fluorescent markers encapsulated in different vesicle populations were used as association markers; when these vesicles associate, the two independent markers should be observed simultaneously in a single detection event. The quenched fluorescent marker and the dequencher, which were encapsulated in separate vesicle populations, were used as the fusion marker. When the internal aqueous solutions mix, the quenched marker is liberated by the dequencher and emits the third fluorescent signal. Although populations of pure POPC vesicles showed no detectable association or fusion, the same populations, oppositely charged by the exogenous addition of charged amphiphiles, showed up to 50% association and 30% fusion upon population analysis of 100,000 giant vesicles. Although a substantial fraction of the vesicles associated in response to a small amount of the charged amphiphiles (5% mole fraction compared to POPC alone), a larger amount of the charged amphiphiles (25%) was needed to induce vesicle fusion. The present methodology also revealed that the association and fusion of giant vesicles was dependent on size, with larger giant vesicles associating and fusing more frequently.
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Affiliation(s)
- Takeshi Sunami
- Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Yamadaoka 1-5, Suita, Osaka 565-0871, Japan
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5
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Stengel G, Simonsson L, Campbell RA, Höök F. Determinants for Membrane Fusion Induced by Cholesterol-Modified DNA Zippers. J Phys Chem B 2008; 112:8264-74. [DOI: 10.1021/jp802005b] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Gudrun Stengel
- Department of Solid State Physics, University of Lund, 22100 Lund, Sweden, and Department of Physical Chemistry, Getingevägen 60, Box 124, 22100 Lund, Sweden
| | - Lisa Simonsson
- Department of Solid State Physics, University of Lund, 22100 Lund, Sweden, and Department of Physical Chemistry, Getingevägen 60, Box 124, 22100 Lund, Sweden
| | - Richard A. Campbell
- Department of Solid State Physics, University of Lund, 22100 Lund, Sweden, and Department of Physical Chemistry, Getingevägen 60, Box 124, 22100 Lund, Sweden
| | - Fredrik Höök
- Department of Solid State Physics, University of Lund, 22100 Lund, Sweden, and Department of Physical Chemistry, Getingevägen 60, Box 124, 22100 Lund, Sweden
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9
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Richard A, Marchi-Artzner V, Lalloz MN, Brienne MJ, Artzner F, Gulik-Krzywicki T, Guedeau-Boudeville MA, Lehn JM. Fusogenic supramolecular vesicle systems induced by metal ion binding to amphiphilic ligands. Proc Natl Acad Sci U S A 2004; 101:15279-84. [PMID: 15492229 PMCID: PMC524461 DOI: 10.1073/pnas.0406625101] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The incorporation of lipophilic ligands into the bilayer membrane of vesicles offers the possibility to induce, upon binding of suitable metal ions, a variety of processes, in particular vesicle aggregation and fusion and generation of vesicle arrays, under the control of specific metal-ligand recognition events. Synthetic bipyridine lipoligands Bn bearing a bipyridine unit as head group were prepared and incorporated into large unilamellar vesicles. The addition of Ni2+ or Co2+ metal ions led to the formation of complexes MBn and MBn2 followed by spontaneous fusion to generate giant multilamellar vesicles. The metal ion complexation was followed by UV spectroscopy and the progressive fusion could be visualized by optical dark-field and fluorescence microscopies. Vesicle fusion occurred without leakage of the aqueous compartments and resulted in the formation of multilamellar giant vesicles because of the stacking of the lipoligands Bn. The fusion process required a long enough oligoethylene glycol spacer and a minimal concentration of lipoligand within the vesicle membrane. Metallosupramolecular systems such as the present one offer an attractive way to induce selective intervesicular processes, such as vesicle fusion, under the control of molecular recognition between specific metal ions and lipoligands incorporated in the bilayer membrane. They provide an approach to the design of artificial "tissue-mimetics" through the generation of polyvesicular arrays of defined architecture and to the control of their functional properties.
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Affiliation(s)
- Antoine Richard
- Laboratoire de Chimie des Interactions Moléculaires and Laboratoire de Physique de la Matière Condensée, Collège de France, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, France
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10
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Scheidt HA, Flasche W, Cismas C, Rost M, Herrmann A, Liebscher J, Huster D. Design and Application of Lipophilic Nucleosides as Building Blocks to Obtain Highly Functional Biological Surfaces. J Phys Chem B 2004. [DOI: 10.1021/jp046606h] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Holger A. Scheidt
- Junior Research Group “Solid-state NMR Studies of the Structure of Membrane-associated Proteins”, Biotechnological-Biomedical Center, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany, Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany, Institute of Biology/Biophysics, Humboldt-University Berlin, Invalidenstr. 42, D-10115 Berlin, Germany, and Institute of Medical Physics and Biophysics, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany
| | - Wolfgang Flasche
- Junior Research Group “Solid-state NMR Studies of the Structure of Membrane-associated Proteins”, Biotechnological-Biomedical Center, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany, Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany, Institute of Biology/Biophysics, Humboldt-University Berlin, Invalidenstr. 42, D-10115 Berlin, Germany, and Institute of Medical Physics and Biophysics, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany
| | - Crina Cismas
- Junior Research Group “Solid-state NMR Studies of the Structure of Membrane-associated Proteins”, Biotechnological-Biomedical Center, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany, Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany, Institute of Biology/Biophysics, Humboldt-University Berlin, Invalidenstr. 42, D-10115 Berlin, Germany, and Institute of Medical Physics and Biophysics, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany
| | - Maximilian Rost
- Junior Research Group “Solid-state NMR Studies of the Structure of Membrane-associated Proteins”, Biotechnological-Biomedical Center, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany, Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany, Institute of Biology/Biophysics, Humboldt-University Berlin, Invalidenstr. 42, D-10115 Berlin, Germany, and Institute of Medical Physics and Biophysics, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany
| | - Andreas Herrmann
- Junior Research Group “Solid-state NMR Studies of the Structure of Membrane-associated Proteins”, Biotechnological-Biomedical Center, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany, Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany, Institute of Biology/Biophysics, Humboldt-University Berlin, Invalidenstr. 42, D-10115 Berlin, Germany, and Institute of Medical Physics and Biophysics, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany
| | - Jürgen Liebscher
- Junior Research Group “Solid-state NMR Studies of the Structure of Membrane-associated Proteins”, Biotechnological-Biomedical Center, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany, Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany, Institute of Biology/Biophysics, Humboldt-University Berlin, Invalidenstr. 42, D-10115 Berlin, Germany, and Institute of Medical Physics and Biophysics, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany
| | - Daniel Huster
- Junior Research Group “Solid-state NMR Studies of the Structure of Membrane-associated Proteins”, Biotechnological-Biomedical Center, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany, Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany, Institute of Biology/Biophysics, Humboldt-University Berlin, Invalidenstr. 42, D-10115 Berlin, Germany, and Institute of Medical Physics and Biophysics, University of Leipzig, Liebigstr. 27, D-04103 Leipzig, Germany
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11
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Heuvingh J, Pincet F, Cribier S. Hemifusion and fusion of giant vesicles induced by reduction of inter-membrane distance. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2004; 14:269-276. [PMID: 15338438 DOI: 10.1140/epje/i2003-10151-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Proteins involved in membrane fusion, such as SNARE or influenza virus hemagglutinin, share the common function of pulling together opposing membranes in closer contact. The reduction of inter-membrane distance can be sufficient to induce a lipid transition phase and thus fusion. We have used functionalized lipids bearing DNA bases as head groups incorporated into giant unilamellar vesicles in order to reproduce the reduction of distance between membranes and to trigger fusion in a model system. In our experiments, two vesicles were isolated and brought into adhesion by the mean of micromanipulation; their evolution was monitored by fluorescence microscopy. Actual fusion only occurred in about 5% of the experiments. In most cases, a state of "hemifusion" is observed and quantified. In this state, the outer leaflets of both vesicles' bilayers merged whereas the inner leaflets and the aqueous inner contents remained independent. The kinetics of the lipid probes redistribution is in good agreement with a diffusion model in which lipids freely diffuse at the circumference of the contact zone between the two vesicles. The minimal density of bridging structures, such as stalks, necessary to explain this redistribution kinetics can be estimated.
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Affiliation(s)
- J Heuvingh
- Laboratoire de Physico-Chimie Moléculaire des Membranes Biologiques, URD-CNRS UMR 7099, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France.
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Szule JA, Coorssen JR. Revisiting the role of SNAREs in exocytosis and membrane fusion. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1641:121-35. [PMID: 12914953 DOI: 10.1016/s0167-4889(03)00095-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
For over a decade SNARE hypotheses have been proposed to explain the mechanism of membrane fusion, yet the field still lacks sufficient evidence to conclusively identify the minimal components of native fusion. Consequently, debate concerning the postulated role(s) of SNAREs in membrane fusion continues. The focus of this review is to revisit original literature with a current perspective. Our analysis begins with the earliest studies of clostridial toxins, leading to various cellular and molecular approaches that have been used to test for the roles of SNAREs in exocytosis. We place much emphasis on distinguishing between specific effects on membrane fusion and effects on other critical steps in exocytosis. Although many systems can be used to study exocytosis, few permit selective access to specific steps in the pathway, such as membrane fusion. Thus, while SNARE proteins are essential to the physiology of exocytosis, assay limitations often prevent definitive conclusions concerning the molecular mechanism of membrane fusion. In all, the SNAREs are more likely to function upstream as modulators or priming factors of fusion.
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Affiliation(s)
- Joseph A Szule
- Cellular and Molecular Neurobiology Research Group, Department of Physiology and Biophysics, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1.
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