1
|
Vial A, Taveneau C, Costa L, Chauvin B, Nasrallah H, Godefroy C, Dosset P, Isambert H, Ngo KX, Mangenot S, Levy D, Bertin A, Milhiet PE. Correlative AFM and fluorescence imaging demonstrate nanoscale membrane remodeling and ring-like and tubular structure formation by septins. NANOSCALE 2021; 13:12484-12493. [PMID: 34225356 DOI: 10.1039/d1nr01978c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Septins are ubiquitous cytoskeletal filaments that interact with the inner plasma membrane and are essential for cell division in eukaryotes. In cellular contexts, septins are often localized at micrometric Gaussian curvatures, where they assemble onto ring-like structures. The behavior of budding yeast septins depends on their specific interaction with inositol phospholipids, enriched at the inner leaflet of the plasma membrane. Septin filaments are built from the non-polar self-assembly of short rods into filaments. However, the molecular mechanisms regulating the interplay with the inner plasma membrane and the resulting interaction with specific curvatures are not fully understood. In this report, we have imaged dynamical molecular assemblies of budding yeast septins on PIP2-containing supported lipid bilayers using a combination of high-speed AFM and correlative AFM-fluorescence microscopy. Our results clearly demonstrate that septins are able to bind to flat supported lipid bilayers and thereafter induce the remodeling of membranes. Short septin rods (octamers subunits) can indeed destabilize supported lipid bilayers and reshape the membrane to form 3D structures such as rings and tubes, demonstrating that long filaments are not necessary for septin-induced membrane buckling.
Collapse
Affiliation(s)
- Anthony Vial
- Centre de Biochimie Structurale (CBS), Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
2
|
Synchronous, Crosstalk-free Correlative AFM and Confocal Microscopies/Spectroscopies. Sci Rep 2020; 10:7098. [PMID: 32341407 PMCID: PMC7184616 DOI: 10.1038/s41598-020-62529-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 03/14/2020] [Indexed: 11/08/2022] Open
Abstract
Microscopies have become pillars of our characterization tools to observe biological systems and assemblies. Correlative and synchronous use of different microscopies relies on the fundamental assumption of non-interference during images acquisitions. In this work, by exploring the correlative use of Atomic Force Microscopy and confocal-Fluorescence-Lifetime Imaging Microscopy (AFM-FLIM), we quantify cross-talk effects occurring during synchronous acquisition. We characterize and minimize optomechanical forces on different AFM cantilevers interfering with normal AFM operation as well as spurious luminescence from the tip and cantilever affecting time-resolved fluorescence detection. By defining non-interfering experimental imaging parameters, we show accurate real-time acquisition and two-dimensional mapping of interaction force, fluorescence lifetime and intensity characterizing morphology (AFM) and local viscosity (FLIM) of gel and fluid phases separation of supported lipid model membranes. Finally, as proof of principle by means of synchronous force and fluorescence spectroscopies, we precisely tune the lifetime of a fluorescent nanodiamond positioned on the AFM tip by controlling its distance from a metallic surface. This opens up a novel pathway of quench sensing to image soft biological samples such as membranes since it does not require tip-sample mechanical contact in contrast with conventional AFM in liquid.
Collapse
|
3
|
Nasrallah H, Vial A, Pocholle N, Soulier J, Costa L, Godefroy C, Bourillot E, Lesniewska E, Milhiet PE. Imaging Artificial Membranes Using High-Speed Atomic Force Microscopy. Methods Mol Biol 2019; 1886:45-59. [PMID: 30374861 DOI: 10.1007/978-1-4939-8894-5_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Supported lipid bilayers represent a very attractive way to mimic biological membranes, especially to investigate molecular mechanisms associated with the lateral segregation of membrane components. Observation of these model membranes with high-speed atomic force microscopy (HS-AFM) allows the capture of both topography and dynamics of membrane components, with a spatial resolution in the nanometer range and image capture time of less than 1 s. In this context, we have developed new protocols adapted for HS-AFM to form supported lipid bilayers on small mica disks using the vesicle fusion or Langmuir-Blodgett methods. In this chapter we describe in detail the protocols to fabricate supported artificial bilayers as well as the main guidelines for HS-AFM imaging of such samples.
Collapse
Affiliation(s)
- Hussein Nasrallah
- INSERM, U1054, Montpellier, France
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, UMR 5048, Montpellier, France
| | - Anthony Vial
- INSERM, U1054, Montpellier, France
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, UMR 5048, Montpellier, France
| | - Nicolas Pocholle
- ICB UMR CNRS 6303, University of Bourgogne Franche-Comte, Dijon, France
| | - Jérémy Soulier
- INSERM, U1054, Montpellier, France
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, UMR 5048, Montpellier, France
| | - Luca Costa
- INSERM, U1054, Montpellier, France
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, UMR 5048, Montpellier, France
| | - Cédric Godefroy
- INSERM, U1054, Montpellier, France
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, UMR 5048, Montpellier, France
| | - Eric Bourillot
- ICB UMR CNRS 6303, University of Bourgogne Franche-Comte, Dijon, France
| | - Eric Lesniewska
- ICB UMR CNRS 6303, University of Bourgogne Franche-Comte, Dijon, France
| | - Pierre-Emmanuel Milhiet
- INSERM, U1054, Montpellier, France.
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, UMR 5048, Montpellier, France.
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Cremona A, Orsini F, Corsetto PA, Hoogenboom BW, Rizzo AM. Reversible Dissolution of Microdomains in Detergent-Resistant Membranes at Physiological Temperature. PLoS One 2015; 10:e0132696. [PMID: 26147107 PMCID: PMC4493071 DOI: 10.1371/journal.pone.0132696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 06/18/2015] [Indexed: 12/14/2022] Open
Abstract
The formation of lipid microdomains ("rafts") is presumed to play an important role in various cellular functions, but their nature remains controversial. Here we report on microdomain formation in isolated, detergent-resistant membranes from MDA-MB-231 human breast cancer cells, studied by atomic force microscopy (AFM). Whereas microdomains were readily observed at room temperature, they shrunk in size and mostly disappeared at higher temperatures. This shrinking in microdomain size was accompanied by a gradual reduction of the height difference between the microdomains and the surrounding membrane, consistent with the behaviour expected for lipids that are laterally segregated in liquid ordered and liquid disordered domains. Immunolabeling experiments demonstrated that the microdomains contained flotillin-1, a protein associated with lipid rafts. The microdomains reversibly dissolved and reappeared, respectively, on heating to and cooling below temperatures around 37 °C, which is indicative of radical changes in local membrane order close to physiological temperature.
Collapse
Affiliation(s)
- Andrea Cremona
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Francesco Orsini
- Dipartimento di Fisica, Università degli Studi di Milano, Milano, Italy
| | - Paola A. Corsetto
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Bart W. Hoogenboom
- London Centre for Nanotechnology, University College London, London, United Kingdom
- Department of Physics and Astronomy, University College London, London, United Kingdom
- * E-mail:
| | - Angela M. Rizzo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| |
Collapse
|
6
|
Godefroy C, Dahmane S, Dosset P, Adam O, Nicolai MC, Ronzon F, Milhiet PE. Mimicking influenza virus fusion using supported lipid bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:11394-11400. [PMID: 25186242 DOI: 10.1021/la502591a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Influenza virus infection is a serious public health problem in the world, and understanding the molecular mechanisms involved in viral replication is crucial. In this paper, we used a minimalist approach based on a lipid bilayer supported on mica, which we imaged by atomic force microscopy (AFM) in a physiological buffer, to analyze the different steps of influenza fusion, from the interaction of intact viruses with the supported bilayer to their complete fusion. Our results show that sialic acid recognition and priming upon acidification are sufficient for a complete fusion with the host cell membrane. After fusion, a flat and continuous membrane was observed. Because of the fragility of the viral membrane that was removed by the tip, most probably due to the disorganization of the matrix layer at acidic pH, fine structural details of ribonucleoproteins (RNP) were obtained. In addition, AFM topography of intact virus in interaction with the supported lipid bilayer confirms that hemeagglutinin and neuraminidase can form isolated clusters within the viral membrane.
Collapse
Affiliation(s)
- Cédric Godefroy
- Institut National de la Santé et de la Recherche Médicale, Unité 1054, 34090 Montpellier, France
| | | | | | | | | | | | | |
Collapse
|
7
|
Lipid bilayers supported on bare and modified gold – Formation, characterization and relevance of lipid rafts. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2013.07.117] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
8
|
Preparation of DOPC and DPPC Supported Planar Lipid Bilayers for Atomic Force Microscopy and Atomic Force Spectroscopy. Int J Mol Sci 2013; 14:3514-39. [PMID: 23389046 PMCID: PMC3588056 DOI: 10.3390/ijms14023514] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 01/29/2013] [Accepted: 02/01/2013] [Indexed: 11/16/2022] Open
Abstract
Cell membranes are typically very complex, consisting of a multitude of different lipids and proteins. Supported lipid bilayers are widely used as model systems to study biological membranes. Atomic force microscopy and force spectroscopy techniques are nanoscale methods that are successfully used to study supported lipid bilayers. These methods, especially force spectroscopy, require the reliable preparation of supported lipid bilayers with extended coverage. The unreliability and a lack of a complete understanding of the vesicle fusion process though have held back progress in this promising field. We document here robust protocols for the formation of fluid phase DOPC and gel phase DPPC bilayers on mica. Insights into the most crucial experimental parameters and a comparison between DOPC and DPPC preparation are presented. Finally, we demonstrate force spectroscopy measurements on DOPC surfaces and measure rupture forces and bilayer depths that agree well with X-ray diffraction data. We also believe our approach to decomposing the force-distance curves into depth sub-components provides a more reliable method for characterising the depth of fluid phase lipid bilayers, particularly in comparison with typical image analysis approaches.
Collapse
|
9
|
Hatta E, Nishimura T. Distribution of cooperative unit size of amphiphilic molecules in the phase coexistence region in Langmuir monolayers. J Colloid Interface Sci 2013; 391:111-5. [PMID: 23110870 DOI: 10.1016/j.jcis.2012.09.074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 09/12/2012] [Accepted: 09/13/2012] [Indexed: 11/29/2022]
Abstract
The dependence of the size of the cooperative unit (C.U.) of amphiphilic molecules on surface pressure (π) in the liquid expanded (LE)-liquid condensed (LC) phase coexistence region of Langmuir monolayers has been formulated and calculated using measured isotherm data. The C.U. size changes largely depending on the surface pressure in the coexistence region: these submicroscopic molecular aggregates are not static objects, but dynamic ones characterized by large fluctuations in size. It has been found that the C.U. size distribution can be a natural consequence of the significant change of monolayer compressibility, which reflects large molecular area density fluctuations, in the coexistence region.
Collapse
Affiliation(s)
- E Hatta
- Nanoelectronics Laboratory, Graduate School of Information Science and Technology, Hokkaido University, Sapporo 060-0814, Japan.
| | | |
Collapse
|
10
|
Levy D, Milhiet PE. Imaging of transmembrane proteins directly incorporated within supported lipid bilayers using atomic force microscopy. Methods Mol Biol 2013; 950:343-357. [PMID: 23086884 DOI: 10.1007/978-1-62703-137-0_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Structural analysis of transmembrane proteins remains a challenge in biology, mainly due to their difficulty in being overexpressed and the required use of detergents that impair different steps of biochemistry classically used to obtain 3D crystals. In this context, we have developed a new technique for protein incorporation within supported lipid bilayers that only requires a few picomoles of protein per assay. Proteins are directly inserted into a detergent-destabilized bilayer that can be imaged in buffer with atomic force microscopy (AFM) allowing structural analysis down to sub-nanometer lateral resolution. In this chapter, we describe the main guidelines for this technique, from the choice of detergent to the requirements for AFM high-resolution imaging.
Collapse
|
11
|
Last JA, Thomasy SM, Croasdale CR, Russell P, Murphy CJ. Compliance profile of the human cornea as measured by atomic force microscopy. Micron 2012; 43:1293-8. [PMID: 22421334 PMCID: PMC3622051 DOI: 10.1016/j.micron.2012.02.014] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 02/17/2012] [Accepted: 02/17/2012] [Indexed: 11/30/2022]
Abstract
The ability to accurately determine the elastic modulus of each layer of the human cornea is a crucial step in the design of better corneal prosthetics. In addition, knowledge of the elastic modulus will allow design of substrates with relevant mechanical properties for in vitro investigations of cellular behavior. Previously, we have reported elastic modulus values for the anterior basement membrane and Descemet's membrane of the human cornea, the surfaces in contact with the epithelial and endothelial cells, respectively. We have completed the compliance profile of the stromal elements of the human cornea by obtaining elastic modulus values for Bowman's layer and the anterior stroma. Atomic force microscopy (AFM) was used to determine the elastic modulus, which is a measure of the tissue stiffness and is inversely proportional to the compliance. The elastic response of the tissue allows analysis with the Hertz equation, a model that provides a relationship between the indentation force and depth and is a function of the tip radius and the modulus of the substrate. The elastic modulus values for each layer of the cornea are: 7.5±4.2 kPa (anterior basement membrane), 109.8±13.2 kPa (Bowman's layer), 33.1±6.1 kPa (anterior stroma), and 50±17.8 kPa (Descemet's membrane). These results indicate that the biophysical properties, including elastic modulus, of each layer of the human cornea are unique and may play a role in the maintenance of homeostasis as well as in the response to therapeutic agents and disease states. The data will also inform the design and fabrication of improved corneal prosthetics.
Collapse
Affiliation(s)
- Julie A. Last
- Laboratory for Optical and Computational Instrumentation and the Materials Science Center, University of Wisconsin-Madison
| | - Sara M. Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis
| | | | - Paul Russell
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis
| | - Christopher J. Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis
- Department of Ophthalmology and Vision Science, School of Medicine, University of California, Davis
| |
Collapse
|
12
|
Picas L, Milhiet PE, Hernández-Borrell J. Atomic force microscopy: a versatile tool to probe the physical and chemical properties of supported membranes at the nanoscale. Chem Phys Lipids 2012. [PMID: 23194897 DOI: 10.1016/j.chemphyslip.2012.10.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Atomic force microscopy (AFM) was developed in the 1980s following the invention of its precursor, scanning tunneling microscopy (STM), earlier in the decade. Several modes of operation have evolved, demonstrating the extreme versatility of this method for measuring the physicochemical properties of samples at the nanoscopic scale. AFM has proved an invaluable technique for visualizing the topographic characteristics of phospholipid monolayers and bilayers, such as roughness, height or laterally segregated domains. Implemented modes such as phase imaging have also provided criteria for discriminating the viscoelastic properties of different supported lipid bilayer (SLB) regions. In this review, we focus on the AFM force spectroscopy (FS) mode, which enables determination of the nanomechanical properties of membrane models. The interpretation of force curves is presented, together with newly emerging techniques that provide complementary information on physicochemical properties that may contribute to our understanding of the structure and function of biomembranes. Since AFM is an imaging technique, some basic indications on how real-time AFM imaging is evolving are also presented at the end of this paper.
Collapse
Affiliation(s)
- Laura Picas
- Institut Curie, CNRS UMR 144, 26 rue d'Ulm, 75248 Paris, France
| | | | | |
Collapse
|
13
|
Morandat S, Azouzi S, Beauvais E, Mastouri A, El Kirat K. Atomic force microscopy of model lipid membranes. Anal Bioanal Chem 2012; 405:1445-61. [DOI: 10.1007/s00216-012-6383-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 08/02/2012] [Accepted: 08/24/2012] [Indexed: 10/27/2022]
|
14
|
Hardy GJ, Nayak R, Alam SM, Shapter JG, Heinrich F, Zauscher S. Biomimetic supported lipid bilayers with high cholesterol content formed by α-helical peptide-induced vesicle fusion. JOURNAL OF MATERIALS CHEMISTRY 2012; 22:19506-19513. [PMID: 23914075 PMCID: PMC3728912 DOI: 10.1039/c2jm32016a] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, we present a technique to create a complex, high cholesterol-containing supported lipid bilayers (SLBs) using α-helical (AH) peptide-induced vesicle fusion. Vesicles consisting of POPC : POPE : POPS : SM : Chol (9.35 : 19.25 : 8.25 : 18.15 : 45.00) were used to form a SLB that models the native composition of the human immunodeficiency virus-1 (HIV-1) lipid envelope. In the absence of AH peptides, these biomimetic vesicles fail to form a complete SLB. We verified and characterized AH peptide-induced vesicle fusion by quartz crystal microbalance with dissipation monitoring, neutron reflectivity, and atomic force microscopy. Successful SLB formation entailed a characteristic frequency shift of -35.4 ± 2.0 Hz and a change in dissipation energy of 1.91 ± 0.52 × 10-6. Neutron reflectivity measurements determined the SLB thickness to be 49.9 +1.9-1.5 Å, and showed the SLB to be 100 +0.0-0.1% complete and void of residual AH peptide after washing. Atomic force microscopy imaging confirmed complete SLB formation and revealed three distinct domains with no visible defects. This vesicle fusion technique gives researchers access to a complex SLB composition with high cholesterol content and thus the ability to better recapitulate the native HIV-1 lipid membrane.
Collapse
Affiliation(s)
- Gregory J. Hardy
- Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA 27708
| | - Rahul Nayak
- Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA 27708
| | - S. Munir Alam
- Human Vaccine Institute, Department of Medicine, Duke University School of Medicine, Durham, North Carolina 27710
| | - Joseph G. Shapter
- Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia
| | - Frank Heinrich
- Department of Physics, Carnegie Mellon University, Pittsburgh PA 15213-3890
- NIST Center for Neutron Research, Gaithersburg MD 20899-6102
| | - Stefan Zauscher
- Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA 27708
| |
Collapse
|
15
|
Pace S, Seantier B, Belamie E, Lautrédou N, Sailor MJ, Milhiet PE, Cunin F. Characterization of phospholipid bilayer formation on a thin film of porous SiO2 by reflective interferometric Fourier transform spectroscopy (RIFTS). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:6960-9. [PMID: 22486481 DOI: 10.1021/la301085t] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Classical methods for characterizing supported artificial phospholipid bilayers include imaging techniques such as atomic force microscopy and fluorescence microscopy. The use in the past decade of surface-sensitive methods such as surface plasmon resonance and ellipsometry, and acoustic sensors such as the quartz crystal microbalance, coupled to the imaging methods, have expanded our understanding of the formation mechanisms of phospholipid bilayers. In the present work, reflective interferometric Fourier transform spectrocopy (RIFTS) is employed to monitor the formation of a planar phospholipid bilayer on an oxidized mesoporous Si (pSiO(2)) thin film. The pSiO(2) substrates are prepared as thin films (3 μm thick) with pore dimensions of a few nanometers in diameter by the electrochemical etching of crystalline silicon, and they are passivated with a thin thermal oxide layer. A thin film of mica is used as a control. Interferometric optical measurements are used to quantify the behavior of the phospholipids at the internal (pores) and external surfaces of the substrates. The optical measurements indicate that vesicles initially adsorb to the pSiO(2) surface as a monolayer, followed by vesicle fusion and conversion to a surface-adsorbed lipid bilayer. The timescale of the process is consistent with prior measurements of vesicle fusion onto mica surfaces. Reflectance spectra calculated using a simple double-layer Fabry-Perot interference model verify the experimental results. The method provides a simple, real-time, nondestructive approach to characterizing the growth and evolution of lipid vesicle layers on the surface of an optical thin film.
Collapse
Affiliation(s)
- Stéphanie Pace
- Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-ENSCM-UM2-UM1, Matériaux Avancés pour la Catalyse et la Santé, Ecole Nationale Supérieure de Chimie de Montpellier, Montpellier, France
| | | | | | | | | | | | | |
Collapse
|
16
|
Dols-Perez A, Fumagalli L, Simonsen AC, Gomila G. Ultrathin spin-coated dioleoylphosphatidylcholine lipid layers in dry conditions: a combined atomic force microscopy and nanomechanical study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:13165-13172. [PMID: 21936555 DOI: 10.1021/la202942j] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Atomic force microscopy (AFM) has been used to study the structural and mechanical properties of low concentrated spin-coated dioleoylphosphatidylcholine (DOPC) layers in dry environment (RH ≈ 0%) at the nanoscale. It is shown that for concentrations in the 0.1-1 mM range the structure of the DOPC spin-coated samples consists of an homogeneous lipid monolayer ∼1.3 nm thick covering the whole substrate on top of which lipid bilayer (or multilayer) micro- and nanometric patches and rims are formed. The thickness of the bilayer structures is found to be ∼4.5 nm (or multiples of this value for multilayer structures), while the lateral dimensions range from micrometers to tens of nanometer depending on the lipid concentration. The force required to break a bilayer (breakthrough force) is found to be ∼0.24 nN. No dependence of the mechanical values on the lateral dimensions of the bilayer structures is evidenced. Remarkably, the thickness and breakthrough force values of the bilayers measured in dry environment are very similar to values reported in the literature for supported DOPC bilayers in pure water.
Collapse
Affiliation(s)
- Aurora Dols-Perez
- Nanobioelec group, Institut de Bioenginyeria de Catalunya (IBEC), Baldiri i Reixac 15-21, 08028 Barcelona, Spain.
| | | | | | | |
Collapse
|
17
|
Li JK, Sullan RMA, Zou S. Atomic force microscopy force mapping in the study of supported lipid bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1308-13. [PMID: 21090659 DOI: 10.1021/la103927a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Investigating the structural and mechanical properties of lipid bilayer membrane systems is vital in elucidating their biological function. One route to directly correlate the morphology of phase-segregated membranes with their indentation and rupture mechanics is the collection of atomic force microscopy (AFM) force maps. These force maps, while containing rich mechanical information, require lengthy processing time due to the large number of force curves needed to attain a high spatial resolution. A force curve analysis toolset was created to perform data extraction, calculation and reporting specifically in studying lipid membrane morphology and mechanical stability. The procedure was automated to allow for high-throughput processing of force maps with greatly reduced processing time. The resulting program was successfully used in systematically analyzing a number of supported lipid membrane systems in the investigation of their structure and nanomechanics.
Collapse
Affiliation(s)
- James K Li
- Department of Chemistry, University of Toronto, Toronto, ON, Canada
| | | | | |
Collapse
|
18
|
Butterfield SM, Lashuel HA. Amyloidogenic protein-membrane interactions: mechanistic insight from model systems. Angew Chem Int Ed Engl 2011; 49:5628-54. [PMID: 20623810 DOI: 10.1002/anie.200906670] [Citation(s) in RCA: 474] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The toxicity of amyloid-forming proteins is correlated with their interactions with cell membranes. Binding events between amyloidogenic proteins and membranes result in mutually disruptive structural perturbations, which are associated with toxicity. Membrane surfaces promote the conversion of amyloid-forming proteins into toxic aggregates, and amyloidogenic proteins, in turn, compromise the structural integrity of the cell membrane. Recent studies with artificial model membranes have highlighted the striking resemblance of the mechanisms of membrane permeabilization of amyloid-forming proteins to those of pore-forming toxins and antimicrobial peptides.
Collapse
Affiliation(s)
- Sara M Butterfield
- Laboratory of Molecular Neurobiology and Neuroproteomics, Swiss Federal Institute of Technology Lausanne (EPFL), SV-BMI-LMNN AI2351, 1015 Lausanne, Switzerland
| | | |
Collapse
|
19
|
Kwak KJ, Valincius G, Liao WC, Hu X, Wen X, Lee A, Yu B, Vanderah DJ, Lu W, Lee LJ. Formation and finite element analysis of tethered bilayer lipid structures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:18199-18208. [PMID: 20977245 DOI: 10.1021/la1021802] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Rapid solvent exchange of an ethanolic solution of diphytanoyl phosphatidylcholine (DPhyPC) in the presence of a mixed self-assembled monolayer (SAM) [thiolipid/β-mercaptoethanol (βME) (3/7 mol/mol) on Au] shows a transition from densely packed tethered bilayer lipid membranes [(dp)tBLMs], to loosely packed tethered bilayer lipid membranes [(lp)tBLMs], and tethered bilayer liposome nanoparticles (tBLNs) with decreasing DPhyPC concentration. The tethered lipidic constructs in the aqueous medium were analyzed by atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS). Finite element analysis (FEA) was applied to interpret spectral EIS features without referring to equivalent circuit modeling. Using structural data obtained earlier from neutron reflectometry and dielectric constants of lipid bilayers, we reproduced experimentally observed features of the electrochemical impedance (EI) spectra of complex surface constructs involving small pinhole defects, large membrane-free patches, and bound liposomes. We demonstrated by FEA that highly insulating (dp)tBLMs with low-defect density exhibit EI spectra in the shape of a perfect semicircle with or without low-frequency upward "tails" in the Cole-Cole representation. Such EI spectra were observed at DPhyPC concentrations of >5 × 10(-3) mol L(-1). While AFM was not able to visualize very small lateral defects in such films, EI spectra unambiguously signaled their presence by increased low frequency "tails". Using FEA we demonstrate that films with large diameter visible defects (>25 nm by AFM) produce EI spectral features consisting of two semicircles of comparable size. Such films were typically obtained at DPhyPC concentrations of <5 × 10(-3) mol L(-1). At DPhyPC concentrations of <1.0 × 10(-3) mol L(-1) the planar bilayer structures were replaced by ellipsoidal liposomes with diameters ranging from 50 to 500 nm as observed in AFM images. Despite the distinct surface morphology change, the EI curves exhibited two semicircle spectral features typical for the large size defects in planar tBLMs. FEA revealed that, to account for these EI features for bound liposome systems (50-500 nm diameter), one needs to assume much lower tBLM conductivities of the submembrane space, which separates the electrode surface and the phospholipid bilayer. Alternatively, FEA indicates that such features may also be observed on composite surfaces containing both bound liposomes and patches of planar bilayers. Triple semicircular features, observed in some of the experimental EI curves, were attributed to an increased complexity of the real tBLMs. The modeling demonstrated that such features are typical for heterogeneous tBLM surfaces containing large patches of different defectiveness levels. By integrating AFM, EIS, and FEA data, our work provides diagnostic criteria allowing the precise characterization of the properties and the morphology of surface supported bilayer systems.
Collapse
Affiliation(s)
- Kwang Joo Kwak
- NSF Nanoscale Science and Engineering, Center for Affordable Nanoengineering of Polymeric Biomedical Devices, Ohio State University, Columbus, Ohio 43210, United States
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Steinem C, Janshoff A. Multicomponent membranes on solid substrates: Interfaces for protein binding. Curr Opin Colloid Interface Sci 2010. [DOI: 10.1016/j.cocis.2010.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
21
|
Vaezian B, Anderton CR, Kraft ML. Discriminating and Imaging Different Phosphatidylcholine Species within Phase-Separated Model Membranes by Principal Component Analysis of TOF-Secondary Ion Mass Spectrometry Images. Anal Chem 2010; 82:10006-14. [DOI: 10.1021/ac101640c] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Bita Vaezian
- Departments of Chemical and Biomolecular Engineering and Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Christopher R. Anderton
- Departments of Chemical and Biomolecular Engineering and Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Mary L. Kraft
- Departments of Chemical and Biomolecular Engineering and Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
22
|
Garcia-Manyes S, Redondo-Morata L, Oncins G, Sanz F. Nanomechanics of Lipid Bilayers: Heads or Tails? J Am Chem Soc 2010; 132:12874-86. [DOI: 10.1021/ja1002185] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Sergi Garcia-Manyes
- Department of Biological Sciences, Columbia University, New York, 10027, New York, Departament de Química Física, Universitat de Barcelona, 08028, Spain, Institut de Bioenginyeria de Catalunya, Barcelona, 08028, Spain, Serveis Cientificotècnics, Universitat de Barcelona, 08028, Spain, and CIBER-BBN, Zaragoza 50018, Spain
| | - Lorena Redondo-Morata
- Department of Biological Sciences, Columbia University, New York, 10027, New York, Departament de Química Física, Universitat de Barcelona, 08028, Spain, Institut de Bioenginyeria de Catalunya, Barcelona, 08028, Spain, Serveis Cientificotècnics, Universitat de Barcelona, 08028, Spain, and CIBER-BBN, Zaragoza 50018, Spain
| | - Gerard Oncins
- Department of Biological Sciences, Columbia University, New York, 10027, New York, Departament de Química Física, Universitat de Barcelona, 08028, Spain, Institut de Bioenginyeria de Catalunya, Barcelona, 08028, Spain, Serveis Cientificotècnics, Universitat de Barcelona, 08028, Spain, and CIBER-BBN, Zaragoza 50018, Spain
| | - Fausto Sanz
- Department of Biological Sciences, Columbia University, New York, 10027, New York, Departament de Química Física, Universitat de Barcelona, 08028, Spain, Institut de Bioenginyeria de Catalunya, Barcelona, 08028, Spain, Serveis Cientificotècnics, Universitat de Barcelona, 08028, Spain, and CIBER-BBN, Zaragoza 50018, Spain
| |
Collapse
|
23
|
Largueze JB, Kirat KE, Morandat S. Preparation of an electrochemical biosensor based on lipid membranes in nanoporous alumina. Colloids Surf B Biointerfaces 2010; 79:33-40. [DOI: 10.1016/j.colsurfb.2010.03.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 03/17/2010] [Accepted: 03/17/2010] [Indexed: 12/25/2022]
|
24
|
Butterfield S, Lashuel H. Wechselwirkungen zwischen amyloidogenen Proteinen und Membranen: Modellsysteme liefern mechanistische Einblicke. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200906670] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
25
|
Oreopoulos J, Epand RF, Epand RM, Yip CM. Peptide-induced domain formation in supported lipid bilayers: direct evidence by combined atomic force and polarized total internal reflection fluorescence microscopy. Biophys J 2010; 98:815-23. [PMID: 20197035 DOI: 10.1016/j.bpj.2009.12.4327] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 11/25/2009] [Accepted: 12/09/2009] [Indexed: 12/01/2022] Open
Abstract
Direct visualization of the mechanism(s) by which peptides induce localized changes to the structure of membranes has high potential for enabling understanding of the structure-function relationship in antimicrobial and cell-penetrating peptides. We have applied a combined imaging strategy to track the interaction of a model antimicrobial peptide, PFWRIRIRR-amide, with bacterial membrane-mimetic supported phospholipid bilayers comprised of POPE/TOCL. Our in situ studies revealed rapid reorganization of the POPE/TOCL membrane into localized TOCL-rich domains with a concomitant change in the organization of the membranes themselves, as reflected by changes in fluorescent-membrane-probe order parameter, upon introduction of the peptide.
Collapse
Affiliation(s)
- John Oreopoulos
- Institute of Biomaterials and Biomedical Engineering, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
26
|
Giocondi MC, Yamamoto D, Lesniewska E, Milhiet PE, Ando T, Le Grimellec C. Surface topography of membrane domains. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:703-18. [DOI: 10.1016/j.bbamem.2009.09.015] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 09/11/2009] [Accepted: 09/20/2009] [Indexed: 12/24/2022]
|
27
|
Nanomechanics of lipid bilayers by force spectroscopy with AFM: A perspective. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:741-9. [DOI: 10.1016/j.bbamem.2009.12.019] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2009] [Revised: 12/16/2009] [Accepted: 12/20/2009] [Indexed: 01/11/2023]
|
28
|
Pace S, Gonzalez P, Devoisselle JM, Milhiet PE, Brunel D, Cunin F. Grafting of monoglyceride molecules for the design of hydrophilic and stable porous silicon surfaces. NEW J CHEM 2010. [DOI: 10.1039/b9nj00469f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
29
|
Sullan RMA, Li JK, Zou S. Quantification of the nanomechanical stability of ceramide-enriched domains. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:12874-12877. [PMID: 19835362 DOI: 10.1021/la903442s] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The quantification of the mechanical stability of lipid bilayers is important in establishing composition-structure-property relations and sheds light on our understanding of the functions of biological membranes. Here, we designed an experiment to directly probe and quantify the nanomechanical stability and rigidity of the ceramide-enriched platforms that play a distinctive role in a variety of cellular processes. Our force mapping results have demonstrated that the ceramide-enriched domains require both methyl beta-cyclodextrin (MbCD) and chloroform treatments to weaken their highly ordered organization, suggesting a lipid packing that is different from that in typical gel states. Our results also show the expulsion of cholesterol from the sphingolipid/cholesterol-enriched domains as a result of ceramide incorporation. This work provides quantitative information on the nanomechanical stability and rigidity of coexisting phase-segregated lipid bilayers with the presence of ceramide-enriched platforms, indicating that that generation of ceramide in cells drastically alters the structural organization and the mechanical property of biological membranes.
Collapse
Affiliation(s)
- Ruby May A Sullan
- Steacie Institute for Molecular Sciences, National Research Council Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada
| | | | | |
Collapse
|
30
|
Sullan RMA, Li JK, Zou S. Direct correlation of structures and nanomechanical properties of multicomponent lipid bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:7471-7. [PMID: 19292499 DOI: 10.1021/la900395w] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Exploring the fine structures and physicochemical properties of physiologically relevant membranes is crucial to understanding biological membrane functions including membrane mechanical stability. We report a direct correlation of the self-organized structures exhibited in phase-segregated supported lipid bilayers consisting of dioleoylphosphatidylcholine/egg sphingomyelin/cholesterol (DEC) in the absence and presence of ceramide (DEC-Ceramide) with their nanomechanical properties using AFM imaging and high-resolution force mapping. Direct incorporation of ceramide into phase-segregated supported lipid bilayers formed ceramide-enriched domains, where the height topography was found to be imaging setpoint dependent. In contrast, liquid ordered domains in both DEC and DEC-Ceramide presented similar heights regardless of AFM imaging settings. Owing to its capability for simultaneous determination of the topology and interaction forces, AFM-based force mapping was used in our study to directly correlate the structures and mechanical responses of different coexisting phases. The intrinsic breakthrough forces, regarded as fingerprints of bilayer stability, along with elastic moduli, adhesion forces, and indentation of the different phases in the bilayers were systematically determined on the nanometer scale, and the results were presented as two-dimensional visual maps using a self-developed code for force curves batch analysis. The mechanical stability and compactness were increased in both liquid ordered domains and fluid disordered phases of DEC-Ceramide, attributed to the influence of ceramide in the organization of the bilayer, as well as to the displacement of cholesterol as a result of the generation of ceramide-enriched domains. The use of AFM force mapping in studying phase segregation of multicomponent lipid membrane systems is a valuable complement to other biophysical techniques such as imaging and spectroscopy, as it provides unprecedented insight into lipid membrane mechanical properties and functions.
Collapse
Affiliation(s)
- Ruby May A Sullan
- Steacie Institute for Molecular Sciences, National Research Council Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada
| | | | | |
Collapse
|
31
|
Goertz MP, Stottrup BL, Houston JE, Zhu XY. Nanomechanical Contrasts of Gel and Fluid Phase Supported Lipid Bilayers. J Phys Chem B 2009; 113:9335-9. [DOI: 10.1021/jp900866h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. P. Goertz
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, Department of Physics, Augsburg College, Minneapolis, Minnesota 55454, and Sandia National Laboratories, Albuquerque, New Mexico 87185
| | - B. L. Stottrup
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, Department of Physics, Augsburg College, Minneapolis, Minnesota 55454, and Sandia National Laboratories, Albuquerque, New Mexico 87185
| | - J. E. Houston
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, Department of Physics, Augsburg College, Minneapolis, Minnesota 55454, and Sandia National Laboratories, Albuquerque, New Mexico 87185
| | - X.-Y. Zhu
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, Department of Physics, Augsburg College, Minneapolis, Minnesota 55454, and Sandia National Laboratories, Albuquerque, New Mexico 87185
| |
Collapse
|