1
|
Miller EJ, Phan MD, Shah J, Honerkamp-Smith AR. Passive and reversible area regulation of supported lipid bilayers in response to fluid flow. Biophys J 2023; 122:2242-2255. [PMID: 36639867 PMCID: PMC10257118 DOI: 10.1016/j.bpj.2023.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/21/2022] [Accepted: 01/09/2023] [Indexed: 01/14/2023] Open
Abstract
Biological and model membranes are frequently subjected to fluid shear stress. However, membrane mechanical responses to flow remain incompletely described. This is particularly true of membranes supported on a solid substrate, and the influences of membrane composition and substrate roughness on membrane flow responses remain poorly understood. Here, we combine microfluidics, fluorescence microscopy, and neutron reflectivity to explore how supported lipid bilayer patches respond to controlled shear stress. We demonstrate that lipid membranes undergo a significant, passive, and partially reversible increase in membrane area due to flow. We show that these fluctuations in membrane area can be constrained, but not prevented, by increasing substrate roughness. Similar flow-induced changes to membrane structure may contribute to the ability of living cells to sense and respond to flow.
Collapse
Affiliation(s)
| | - Minh D Phan
- Large-Scale Structures Group, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee; Center for Neutron Science, Department of Chemical & Biomolecular Engineering, University of Delaware, Newark, Delaware
| | | | | |
Collapse
|
2
|
Ratajczak AM, Sasidharan S, Rivera Gonzalez XI, Miller EJ, Socrier L, Anthony AA, Honerkamp-Smith AR. Measuring flow-mediated protein drift across stationary supported lipid bilayers. Biophys J 2023; 122:1720-1731. [PMID: 37020419 PMCID: PMC10183372 DOI: 10.1016/j.bpj.2023.03.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 03/13/2023] [Accepted: 03/29/2023] [Indexed: 04/07/2023] Open
Abstract
Fluid flow near biological membranes influences cell functions such as development, motility, and environmental sensing. Flow can laterally transport extracellular membrane proteins located at the cell-fluid interface. To determine whether this transport contributes to flow signaling in cells, quantitative knowledge of the forces acting on membrane proteins is required. Here, we demonstrate a method for measuring flow-mediated lateral transport of lipid-anchored proteins. We rupture giant unilamellar vesicles to form discrete patches of supported membrane inside rectangular microchannels and then allow proteins to bind to the upper surface of the membrane. While applying flow, we observe the formation of protein concentration gradients that span the membrane patch. By observing how these gradients dynamically respond to changes in applied shear stress, we determine the flow mobility of the lipid-anchored protein. We use simplified model membranes and proteins to demonstrate our method's sensitivity and reproducibility. Our intention was to design a quantitative, reliable method and analysis for protein mobility that we will use to compare flow transport for a variety of proteins, lipid anchors, and membranes in model systems and on living cells.
Collapse
Affiliation(s)
| | | | | | - Ethan J Miller
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania
| | - Larissa Socrier
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania
| | - Autumn A Anthony
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania
| | | |
Collapse
|
3
|
Kerkhoff Y, Azizi L, Mykuliak VV, Hytönen VP, Block S. Microfluidics-Based Force Spectroscopy Enables High-Throughput Force Experiments with Sub-Nanometer Resolution and Sub-Piconewton Sensitivity. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206713. [PMID: 36631276 DOI: 10.1002/smll.202206713] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/23/2022] [Indexed: 06/17/2023]
Abstract
Several techniques have been established to quantify the mechanicals of single molecules. However, most of them show only limited capabilities of parallelizing the measurement by performing many individual measurements simultaneously. Herein, a microfluidics-based single-molecule force spectroscopy method, which achieves sub-nanometer spatial resolution and sub-piconewton sensitivity and is capable of simultaneously quantifying hundreds of single-molecule targets in parallel, is presented. It relies on a combination of total internal reflection microscopy and microfluidics, in which monodisperse fluorescent beads are immobilized on the bottom of a microfluidic channel by macromolecular linkers. Application of a flow generates a well-defined shear force acting on the beads, whereas the nanomechanical linker response is quantified based on the force-induced displacement of individual beads. To handle the high amount of data generated, a cluster analysis which is capable of a semi-automatic identification of measurement artifacts and molecular populations is implemented. The method is validated by probing the mechanical response polyethylene glycol linkers and binding strength of biotin-NeutrAvidin complexes. Two energy barriers (at 3 and 5.7 Å, respectively) in the biotin-NeutrAvidin interaction are resolved and the unfolding behavior of talin's rod domain R3 in the force range between 1 to ≈10 pN is probed.
Collapse
Affiliation(s)
- Yannic Kerkhoff
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195, Berlin, Germany
| | - Latifeh Azizi
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Tampere, FI-33520, Finland
| | - Vasyl V Mykuliak
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Tampere, FI-33520, Finland
| | - Vesa P Hytönen
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Tampere, FI-33520, Finland
- Fimlab Laboratories, Biokatu 4, Tampere, FI-33520, Finland
| | - Stephan Block
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195, Berlin, Germany
| |
Collapse
|
4
|
Anthony AA, Sahin O, Yapici MK, Rogers D, Honerkamp-Smith AR. Systematic measurements of interleaflet friction in supported bilayers. Biophys J 2022; 121:2981-2993. [PMID: 35754183 PMCID: PMC9388387 DOI: 10.1016/j.bpj.2022.06.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/23/2022] [Accepted: 06/22/2022] [Indexed: 11/20/2022] Open
Abstract
When lipid membranes curve or are subjected to strong shear forces, the two apposed leaflets of the bilayer slide past each other. The drag that one leaflet creates on the other is quantified by the coefficient of interleaflet friction, b. Existing measurements of this coefficient range over several orders of magnitude, so we used a recently developed microfluidic technique to measure it systematically in supported lipid membranes. Fluid shear stress was used to force the top leaflet of a supported membrane to slide over the stationary lower leaflet. Here, we show that this technique yields a reproducible measurement of the friction coefficient and is sensitive enough to detect differences in friction between membranes made from saturated and unsaturated lipids. Adding cholesterol to saturated and unsaturated membranes increased interleaflet friction significantly. We also discovered that fluid shear stress can reversibly induce gel phase in supported lipid bilayers that are close to the gel-transition temperature.
Collapse
|
5
|
Meredith SA, Yoneda T, Hancock AM, Connell SD, Evans SD, Morigaki K, Adams PG. Model Lipid Membranes Assembled from Natural Plant Thylakoids into 2D Microarray Patterns as a Platform to Assess the Organization and Photophysics of Light-Harvesting Proteins. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2006608. [PMID: 33690933 DOI: 10.1002/smll.202006608] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Natural photosynthetic "thylakoid" membranes found in green plants contain a large network of light-harvesting (LH) protein complexes. Rearrangement of this photosynthetic machinery, laterally within stacked membranes called "grana", alters protein-protein interactions leading to changes in the energy balance within the system. Preparation of an experimentally accessible model system that allows the detailed investigation of these complex interactions can be achieved by interfacing thylakoid membranes and synthetic lipids into a template comprised of polymerized lipids in a 2D microarray pattern on glass surfaces. This paper uses this system to interrogate the behavior of LH proteins at the micro- and nanoscale and assesses the efficacy of this model. A combination of fluorescence lifetime imaging and atomic force microscopy reveals the differences in photophysical state and lateral organization between native thylakoid and hybrid membranes, the mechanism of LH protein incorporation into the developing hybrid membranes, and the nanoscale structure of the system. The resulting model system within each corral is a high-quality supported lipid bilayer that incorporates laterally mobile LH proteins. Photosynthetic activity is assessed in the hybrid membranes versus proteoliposomes, revealing that commonly used photochemical assays to test the electron transfer activity of photosystem II may actually produce false-positive results.
Collapse
Affiliation(s)
- Sophie A Meredith
- School of Physics and Astronomy and The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Takuro Yoneda
- Graduate School of Agricultural Science and Biosignal Research Center, Kobe University, Rokkodaicho 1-1, Nada, Kobe, 657-8501, Japan
| | - Ashley M Hancock
- School of Physics and Astronomy and The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Simon D Connell
- School of Physics and Astronomy and The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Stephen D Evans
- School of Physics and Astronomy and The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Kenichi Morigaki
- Graduate School of Agricultural Science and Biosignal Research Center, Kobe University, Rokkodaicho 1-1, Nada, Kobe, 657-8501, Japan
| | - Peter G Adams
- School of Physics and Astronomy and The Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| |
Collapse
|
6
|
Miller EJ, Ratajczak AM, Anthony AA, Mottau M, Rivera Gonzalez XI, Honerkamp-Smith AR. Divide and conquer: How phase separation contributes to lateral transport and organization of membrane proteins and lipids. Chem Phys Lipids 2020; 233:104985. [DOI: 10.1016/j.chemphyslip.2020.104985] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 09/18/2020] [Accepted: 09/28/2020] [Indexed: 01/06/2023]
|
7
|
Dong C, Choi YK, Lee J, Zhang XF, Honerkamp-Smith A, Widmalm G, Lowe-Krentz LJ, Im W. Structure, Dynamics, and Interactions of GPI-Anchored Human Glypican-1 with Heparan Sulfates in a Membrane. Glycobiology 2020; 31:593-602. [PMID: 33021626 DOI: 10.1093/glycob/cwaa092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/24/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022] Open
Abstract
Glypican-1 and its heparan sulfate (HS) chains play important roles in modulating many biological processes including growth factor signaling. Glypican-1 is bound to a membrane surface via a glycosylphosphatidylinositol (GPI)-anchor. In this study, we used all-atom molecular modeling and simulation to explore the structure, dynamics, and interactions of GPI-anchored glypican-1, three HS chains, membranes, and ions. The folded glypican-1 core structure is stable, but has substantial degrees of freedom in terms of movement and orientation with respect to the membrane due to the long unstructured C-terminal region linking the core to the GPI-anchor. With unique structural features depending on the extent of sulfation, high flexibility of HS chains can promote multi-site interactions with surrounding molecules near and above the membrane. This study is a first step toward all-atom molecular modeling and simulation of the glycocalyx, as well as its modulation of interactions between growth factors and their receptors.
Collapse
Affiliation(s)
- Chuqiao Dong
- Department of Mechanical Engineering and Mechanicss, Lehigh University, Bethlehem, PA, 18015, United States
| | - Yeol Kyo Choi
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, 18015, United States
| | - Jumin Lee
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, 18015, United States
| | - X Frank Zhang
- Department of Mechanical Engineering and Mechanicss, Lehigh University, Bethlehem, PA, 18015, United States.,Department of Bioengineering, Lehigh University, Bethlehem, PA, 18015, United States
| | | | - Göran Widmalm
- Department of Organic Chemistry, Stockholm University, S-106 91 Stockholm, Sweden
| | - Linda J Lowe-Krentz
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, 18015, United States
| | - Wonpil Im
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, 18015, United States.,Department of Bioengineering, Lehigh University, Bethlehem, PA, 18015, United States.,Department of Chemistry, Lehigh University, Bethlehem, PA, 18015, United States
| |
Collapse
|
8
|
Verardo D, Agnarsson B, Zhdanov VP, Höök F, Linke H. Single-Molecule Detection with Lightguiding Nanowires: Determination of Protein Concentration and Diffusivity in Supported Lipid Bilayers. NANO LETTERS 2019; 19:6182-6191. [PMID: 31369284 DOI: 10.1021/acs.nanolett.9b02226] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Determining the surface concentration and diffusivity of cell-membrane-bound molecules is central to the understanding of numerous important biochemical processes taking place at cell membranes. Here we use the high aspect ratio and lightguiding properties of semiconductor nanowires (NWs) to detect the presence of single freely diffusing proteins bound to a lipid bilayer covering the NW surface. Simultaneous observation of light-emission dynamics of hundreds of individual NWs occurring on the time scale of only a few seconds is interpreted using analytical models and employed to determine both surface concentration and diffusivity of cholera toxin subunit B (CTxB) bound to GM1 gangliosides in supported lipid bilayer (SLB) at surface concentrations down to below one CTxB per μm2. In particular, a decrease in diffusivity was observed with increasing GM1 content in the SLB, suggesting increasing multivalent binding of CTxB to GM1. The lightguiding capability of the NWs makes the method compatible with conventional epifluorescence microscopy, and it is shown to work well for both photostable and photosensitive dyes. These features make the concept an interesting complement to existing techniques for studying the diffusivity of low-abundance cell-membrane-bound molecules, expanding the rapidly growing use of semiconductor NWs in various bioanalytical sensor applications and live cell studies.
Collapse
Affiliation(s)
- Damiano Verardo
- NanoLund and Solid State Physics , Lund University , 22100 Lund , Sweden
| | - Björn Agnarsson
- Department of Physics , Chalmers University of Technology , 41296 Göteborg , Sweden
| | - Vladimir P Zhdanov
- Department of Physics , Chalmers University of Technology , 41296 Göteborg , Sweden
- Boreskov Institute of Catalysis , Russian Academy of Sciences , Novosibirsk 630090 , Russia
| | - Fredrik Höök
- Department of Physics , Chalmers University of Technology , 41296 Göteborg , Sweden
| | - Heiner Linke
- NanoLund and Solid State Physics , Lund University , 22100 Lund , Sweden
| |
Collapse
|
9
|
Lichtenberg JY, Ling Y, Kim S. Non-Specific Adsorption Reduction Methods in Biosensing. SENSORS (BASEL, SWITZERLAND) 2019; 19:E2488. [PMID: 31159167 PMCID: PMC6603772 DOI: 10.3390/s19112488] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 05/24/2019] [Accepted: 05/27/2019] [Indexed: 01/05/2023]
Abstract
Non-specific adsorption (NSA) is a persistent problem that negatively affects biosensors, decreasing sensitivity, specificity, and reproducibility. Passive and active removal methods exist to remedy this issue, by coating the surface or generating surface forces to shear away weakly adhered biomolecules, respectively. However, many surface coatings are not compatible or effective for sensing, and thus active removal methods have been developed to combat this phenomenon. This review aims to provide an overview of methods of NSA reduction in biosensing, focusing on the shift from passive methods to active methods in the past decade. Attention is focused on protein NSA, due to their common use in biosensing for biomarker diagnostics. To our knowledge, this is the first review to comprehensively discuss active NSA removal methods. Lastly, the challenges and future perspectives of NSA reduction in biosensing are discussed.
Collapse
Affiliation(s)
- Jessanne Y Lichtenberg
- Department of Electrical and Computer Engineering, School of Engineering, Baylor University, Waco, TX 76798, USA.
| | - Yue Ling
- Department of Mechanical Engineering, School of Engineering, Baylor University, Waco, TX 76798, USA.
| | - Seunghyun Kim
- Department of Electrical and Computer Engineering, School of Engineering, Baylor University, Waco, TX 76798, USA.
| |
Collapse
|
10
|
Bi H, Wang X, Han X, Voïtchovsky K. Impact of Electric Fields on the Nanoscale Behavior of Lipid Monolayers at the Surface of Graphite in Solution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:9561-9571. [PMID: 30028144 DOI: 10.1021/acs.langmuir.8b01631] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The nanoscale organization and dynamics of lipid molecules in self-assembled membranes is central to the biological function of cells and in the technological development of synthetic lipid structures as well as in devices such as biosensors. Here, we explore the nanoscale molecular arrangement and dynamics of lipids assembled in monolayers at the surface of highly ordered pyrolytic graphite (HOPG), in different ionic solutions, and under electrical potentials. Using a combination of atomic force microscopy and fluorescence recovery after photobleaching, we show that HOPG is able to support fully formed and fluid lipid membranes, but mesoscale order and corrugations can be observed depending on the type of the lipid considered (1,2-dioleoyl- sn-glycero-3-phosphocholine, 1,2-dioleoyl- sn-glycero-3-phospho-l-serine (DOPS), and 1,2-dioleoyl-3-trimethylammoniumpropane) and the ion present (Na+, Ca2+, Cl-). Interfacial solvation forces and ion-specific effects dominate over the electrostatic changes induced by moderate electric fields (±1.0 V vs Ag/AgCl reference electrode) with particularly marked effects in the presence of calcium, and for DOPS. Our results provide insights into the interplay between the molecular, ionic, and electrostatic interactions and the formation of dynamical ordered structures in fluid lipid membranes.
Collapse
Affiliation(s)
- Hongmei Bi
- College of Science , Heilongjiang Bayi Agricultural University , Daqing 163319 , China
| | - Xuejing Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering , Harbin Institute of Technology , Harbin 150001 , China
| | - Xiaojun Han
- State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering , Harbin Institute of Technology , Harbin 150001 , China
| | | |
Collapse
|
11
|
Bioinspired, nanoscale approaches in contemporary bioanalytics (Review). Biointerphases 2018; 13:040801. [DOI: 10.1116/1.5037582] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
12
|
Block S. Brownian Motion at Lipid Membranes: A Comparison of Hydrodynamic Models Describing and Experiments Quantifying Diffusion within Lipid Bilayers. Biomolecules 2018; 8:biom8020030. [PMID: 29789471 PMCID: PMC6023006 DOI: 10.3390/biom8020030] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/07/2018] [Accepted: 05/16/2018] [Indexed: 12/29/2022] Open
Abstract
The capability of lipid bilayers to exhibit fluid-phase behavior is a fascinating property, which enables, for example, membrane-associated components, such as lipids (domains) and transmembrane proteins, to diffuse within the membrane. These diffusion processes are of paramount importance for cells, as they are for example involved in cell signaling processes or the recycling of membrane components, but also for recently developed analytical approaches, which use differences in the mobility for certain analytical purposes, such as in-membrane purification of membrane proteins or the analysis of multivalent interactions. Here, models describing the Brownian motion of membrane inclusions (lipids, peptides, proteins, and complexes thereof) in model bilayers (giant unilamellar vesicles, black lipid membranes, supported lipid bilayers) are summarized and model predictions are compared with the available experimental data, thereby allowing for evaluating the validity of the introduced models. It will be shown that models describing the diffusion in freestanding (Saffman-Delbrück and Hughes-Pailthorpe-White model) and supported bilayers (the Evans-Sackmann model) are well supported by experiments, though only few experimental studies have been published so far for the latter case, calling for additional tests to reach the same level of experimental confirmation that is currently available for the case of freestanding bilayers.
Collapse
Affiliation(s)
- Stephan Block
- Department of Chemistry and Biochemistry, Freie Universität Berlin, D-14195 Berlin, Germany.
| |
Collapse
|
13
|
Bao P, Cartron ML, Sheikh KH, Johnson BRG, Hunter CN, Evans SD. Controlling transmembrane protein concentration and orientation in supported lipid bilayers. Chem Commun (Camb) 2018; 53:4250-4253. [PMID: 28361139 DOI: 10.1039/c7cc01023k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The trans-membrane protein - proteorhodopsin (pR) has been incorporated into supported lipid bilayers (SLB). In-plane electric fields have been used to manipulate the orientation and concentration of these proteins, within the SLB, through electrophoresis leading to a 25-fold increase concentration of pR.
Collapse
Affiliation(s)
- P Bao
- School of Physics & Astronomy, University of Leeds, LS2 9JT, UK.
| | - M L Cartron
- Department of Molecular Biology & Biotechnology, University of Sheffield, S10 2TH, UK
| | - K H Sheikh
- School of Biomedical Science, University of Leeds, LS2 9JT, UK
| | - B R G Johnson
- School of Physics & Astronomy, University of Leeds, LS2 9JT, UK.
| | - C N Hunter
- Department of Molecular Biology & Biotechnology, University of Sheffield, S10 2TH, UK
| | - S D Evans
- School of Physics & Astronomy, University of Leeds, LS2 9JT, UK.
| |
Collapse
|
14
|
Lundgren A, Fast BJ, Block S, Agnarsson B, Reimhult E, Gunnarsson A, Höök F. Affinity Purification and Single-Molecule Analysis of Integral Membrane Proteins from Crude Cell-Membrane Preparations. NANO LETTERS 2018; 18:381-385. [PMID: 29231738 DOI: 10.1021/acs.nanolett.7b04227] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The function of integral membrane proteins is critically dependent on their naturally surrounding lipid membrane. Detergent-solubilized and purified membrane proteins are therefore often reconstituted into cell-membrane mimics and analyzed for their function with single-molecule microscopy. Expansion of this approach toward a broad range of pharmaceutically interesting drug targets and biomarkers however remains hampered by the fact that these proteins have low expression levels, and that detergent solubilization and reconstitution often cause protein conformational changes and loss of membrane-specific cofactors, which may impair protein function. To overcome this limitation, we here demonstrate how antibody-modified nanoparticles can be used to achieve affinity purification and enrichment of selected integral membrane proteins directly from cell membrane preparations. Nanoparticles were first bound to the ectodomain of β-secretase 1 (BACE1) contained in cell-derived membrane vesicles. In a subsequent step, these were merged into a continuous supported membrane in a microfluidic channel. Through the extended nanoparticle tag, a weak (∼fN) hydrodynamic force could be applied, inducing directed in-membrane movement of targeted BACE1 exclusively. This enabled selective thousand-fold enrichment of the targeted membrane protein while preserving a natural lipid environment. In addition, nanoparticle-targeting also enabled simultaneous tracking analysis of each individual manipulated protein, revealing how their mobility changed when moved from one lipid environment to another. We therefore believe this approach will be particularly useful for separation in-line with single-molecule analysis, eventually opening up for membrane-protein sorting devices analogous to fluorescence-activated cell sorting.
Collapse
Affiliation(s)
- Anders Lundgren
- Department of Physics, Chalmers University of Technology , 41296 Göteborg, Sweden
- Department of Nanobiotechnology, University of Natural Resources and Life Sciences , 1190 Vienna, Austria
| | - Björn Johansson Fast
- Department of Physics, Chalmers University of Technology , 41296 Göteborg, Sweden
| | - Stephan Block
- Department of Physics, Chalmers University of Technology , 41296 Göteborg, Sweden
| | - Björn Agnarsson
- Department of Physics, Chalmers University of Technology , 41296 Göteborg, Sweden
| | - Erik Reimhult
- Department of Nanobiotechnology, University of Natural Resources and Life Sciences , 1190 Vienna, Austria
| | - Anders Gunnarsson
- Discovery Sciences, Innovative Medicines and Early Development Biotech Unit, AstraZeneca , 43183 Mölndal, Sweden
| | - Fredrik Höök
- Department of Physics, Chalmers University of Technology , 41296 Göteborg, Sweden
| |
Collapse
|
15
|
Gunnarsson A, Simonsson Nyström L, Burazerovic S, Gunnarsson J, Snijder A, Geschwindner S, Höök F. Affinity Capturing and Surface Enrichment of a Membrane Protein Embedded in a Continuous Supported Lipid Bilayer. ChemistryOpen 2016; 5:445-449. [PMID: 27777836 PMCID: PMC5062009 DOI: 10.1002/open.201600070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Indexed: 11/26/2022] Open
Abstract
Investigations of ligand-binding kinetics to membrane proteins are hampered by their poor stability and low expression levels, which often translates into sensitivity-related limitations impaired by low signal-to-noise ratios. Inspired by affinity capturing of water-soluble proteins, which utilizes water as the mobile phase, we demonstrate affinity capturing and local enrichment of membrane proteins by using a fluid lipid bilayer as the mobile phase. Specific membrane-protein capturing and enrichment in a microfluidic channel was accomplished by immobilizing a synthesized trivalent nitrilotriacetic acid (tris-NTA)-biotin conjugate. A polymer-supported lipid bilayer containing His6-tagged β-secretase (BACE) was subsequently laterally moved over the capture region by using a hydrodynamic flow. Specific enrichment of His6-BACE in the Ni2+-NTA-modified region of the substrate resulted in a stationary three-fold increase in surface coverage, and an accompanied increase in ligand-binding response.
Collapse
Affiliation(s)
| | | | - Sabina Burazerovic
- Department of Applied PhysicsChalmers University of Technology412 96GöteborgSweden
| | | | - Arjan Snijder
- Discovery SciencesAstraZeneca R&D Mölndal43183MölndalSweden
| | | | - Fredrik Höök
- Department of Applied PhysicsChalmers University of Technology412 96GöteborgSweden
| |
Collapse
|
16
|
Two-dimensional flow nanometry of biological nanoparticles for accurate determination of their size and emission intensity. Nat Commun 2016; 7:12956. [PMID: 27658367 PMCID: PMC5036154 DOI: 10.1038/ncomms12956] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/18/2016] [Indexed: 01/07/2023] Open
Abstract
Biological nanoparticles (BNPs) are of high interest due to their key role in various biological processes and use as biomarkers. BNP size and composition are decisive for their functions, but simultaneous determination of both properties with high accuracy remains challenging. Optical microscopy allows precise determination of fluorescence/scattering intensity, but not the size of individual BNPs. The latter is better determined by tracking their random motion in bulk, but the limited illumination volume for tracking this motion impedes reliable intensity determination. Here, we show that by attaching BNPs to a supported lipid bilayer, subjecting them to hydrodynamic flows and tracking their motion via surface-sensitive optical imaging enable determination of their diffusion coefficients and flow-induced drifts, from which accurate quantification of both BNP size and emission intensity can be made. For vesicles, the accuracy of this approach is demonstrated by resolving the expected radius-squared dependence of their fluorescence intensity for radii down to 15 nm.
Collapse
|
17
|
Blosser MC, Honerkamp-Smith AR, Han T, Haataja M, Keller SL. Transbilayer Colocalization of Lipid Domains Explained via Measurement of Strong Coupling Parameters. Biophys J 2016; 109:2317-27. [PMID: 26636943 DOI: 10.1016/j.bpj.2015.10.031] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 10/16/2015] [Accepted: 10/26/2015] [Indexed: 01/03/2023] Open
Abstract
When micron-scale compositional heterogeneity develops in membranes, the distribution of lipids on one face of the membrane strongly affects the distribution on the other. Specifically, when lipid membranes phase separate into coexisting liquid phases, domains in each monolayer leaflet of the membrane are colocalized with domains in the opposite leaflet. Colocalized domains have never been observed to spontaneously move out of registry. This result indicates that the lipid compositions in one leaflet are strongly coupled to compositions in the opposing leaflet. Predictions of the interleaflet coupling parameter, Λ, vary by a factor of 50. We measure the value of Λ by applying high shear forces to supported lipid bilayers. This causes the upper leaflet to slide over the lower leaflet, moving domains out of registry. We find that the threshold shear stress required to deregister domains in the upper and lower leaflets increases with the inverse length of domains. We derive a simple, closed-form expression relating the threshold shear to Λ, and find Λ = 0.016 ± 0.004 kBT/nm2.
Collapse
Affiliation(s)
- Matthew C Blosser
- Departments of Chemistry and Physics, University of Washington, Seattle, Washington
| | - Aurelia R Honerkamp-Smith
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, United Kingdom
| | - Tao Han
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey
| | - Mikko Haataja
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey
| | - Sarah L Keller
- Departments of Chemistry and Physics, University of Washington, Seattle, Washington.
| |
Collapse
|
18
|
Hu SK, Huang LT, Chao L. Membrane species mobility under in-lipid-membrane forced convection. SOFT MATTER 2016; 12:6954-6963. [PMID: 27476605 DOI: 10.1039/c6sm01145d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Processing and managing cell membrane proteins for characterization while maintaining their intact structure is challenging. Hydrodynamic flow has been used to transport membrane species in supported lipid bilayers (SLBs) where the hydrophobic cores of the membrane species can be protected during processing. However, the forced convection mechanism of species embedded in lipid bilayers is still unclear. Developing a controlled SLB platform with a practical model to predict the membrane species mobility in the platform under in-lipid-membrane forced convection is imperative to ensure the practical applicability of SLBs in processing and managing membrane species with various geometrical properties. The mobility of membrane species is affected by the driving force from the aqueous environment in addition to the frictions from the lipid bilayer, in which both lipid leaflets may exhibit different speeds relative to that of the moving species. In this study, we developed a model, based on the applied driving force and the possible frictional resistances that the membrane species encounter, to predict how the mobility under in-lipid-membrane forced convection is influenced by the sizes of the species' hydrophilic portion in the aqueous environment and the hydrophobic portion embedded in the membrane. In addition, we used a microfluidic device for controlling the flow to arrange the lipid membrane and the tested membrane species in the desirable locations in order to obtain a SLB platform which can provide clear mobility responses of the species without disturbance from the species dispersion effect. The model predictions were consistent with the experimental observations, with the sliding friction coefficient between the upper leaflet and the hydrophilic portion of the species as the only regressed parameter. The result suggests that not only the lateral drag frictions from the lipid layers but also the sliding frictions between the species and the lipid layer planes could significantly influence the species mobility. The consistency between the experimental results and the model predictions suggests that our model based on lateral drag and sliding frictions between the species and the lipid leaflets can be used to describe the mobility of half-transmembrane species. We also demonstrated the possibility of how the scope of this model can be broadened to describe the mobility of transmembrane proteins extending through both lipid leaflets.
Collapse
Affiliation(s)
- Shu-Kai Hu
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan.
| | - Ling-Ting Huang
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan.
| | - Ling Chao
- Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan.
| |
Collapse
|
19
|
van Weerd J, Karperien M, Jonkheijm P. Supported Lipid Bilayers for the Generation of Dynamic Cell-Material Interfaces. Adv Healthc Mater 2015; 4:2743-79. [PMID: 26573989 DOI: 10.1002/adhm.201500398] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/03/2015] [Indexed: 12/13/2022]
Abstract
Supported lipid bilayers (SLB) offer unique possibilities for studying cellular membranes and have been used as a synthetic architecture to interact with cells. Here, the state-of-the-art in SLB-based technology is presented. The fabrication, analysis, characteristics and modification of SLBs are described in great detail. Numerous strategies to form SLBs on different substrates, and the means to patteren them, are described. The use of SLBs as model membranes for the study of membrane organization and membrane processes in vitro is highlighted. In addition, the use of SLBs as a substratum for cell analysis is presented, with discrimination between cell-cell and cell-extracellular matrix (ECM) mimicry. The study is concluded with a discussion of the potential for in vivo applications of SLBs.
Collapse
Affiliation(s)
- Jasper van Weerd
- Bioinspired Molecular Engineering; University of Twente; PO Box 217 7500 AE Enschede The Netherlands
- Dept. of Developmental BioEngineering; MIRA Institute for Biomedical Technology and Technical Medicine; University of Twente; PO Box 217 7500 AE Enschede The Netherlands
- Molecular Nanofabrication Group, MESA+; University of Twente; Enschede 7500 AE The Netherlands
| | - Marcel Karperien
- Dept. of Developmental BioEngineering; MIRA Institute for Biomedical Technology and Technical Medicine; University of Twente; PO Box 217 7500 AE Enschede The Netherlands
| | - Pascal Jonkheijm
- Bioinspired Molecular Engineering; University of Twente; PO Box 217 7500 AE Enschede The Netherlands
- Molecular Nanofabrication Group, MESA+; University of Twente; Enschede 7500 AE The Netherlands
| |
Collapse
|
20
|
Jönsson P, Jönsson B. Hydrodynamic Forces on Macromolecules Protruding from Lipid Bilayers Due to External Liquid Flows. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:12708-12718. [PMID: 26523331 DOI: 10.1021/acs.langmuir.5b03421] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
It has previously been observed that an externally applied hydrodynamic shear flow above a fluid lipid bilayer can change the local concentration of macromolecules that are associated with the lipid bilayer. The external liquid flow results in a hydrodynamic force on molecules protruding from the lipid bilayer, causing them to move in the direction of the flow. However, there has been no quantitative study about the magnitude of these forces. We here use finite element simulations to investigate how the magnitude of the external hydrodynamic forces varies with the size and shape of the studied macromolecule. The simulations show that the hydrodynamic force is proportional to the effective hydrodynamic area of the studied molecule, Ahydro, multiplied by the mean hydrodynamic shear stress acting on the membrane surface, σhydro. The parameter Ahydro depends on the size and shape of the studied macromolecule above the lipid bilayer and scales with the cross-sectional area of the molecule. We also investigate how hydrodynamic shielding from other surrounding macromolecules decreases Ahydro when the surface coverage of the shielding macromolecules increases. Experiments where the protein streptavidin is anchored to a supported lipid bilayer on the floor of a microfluidic channel were finally performed at three different surface concentrations, Φ = 1%, 6%, and 10%, where the protein is being moved relative to the lipid bilayer by a liquid flow through the channel. From photobleaching measurements of fluorescently labeled streptavidin we found the experimental drift data to be within good accuracy of the simulated results, less than 12% difference, indicating the validity of the results obtained from the simulations. In addition to giving a deeper insight into how a liquid flow can affect membrane-associated molecules in a lipid bilayer, we also see an interesting potential of using hydrodynamic flow experiments together with the obtained results to study the size and the intermolecular forces between macromolecules in membranes and lipid bilayers.
Collapse
Affiliation(s)
- Peter Jönsson
- Division of Physical Chemistry and ‡Division of Biophysical Chemistry, Lund University , SE-22100 Lund, Sweden
| | - Bengt Jönsson
- Division of Physical Chemistry and ‡Division of Biophysical Chemistry, Lund University , SE-22100 Lund, Sweden
| |
Collapse
|
21
|
Pace H, Simonsson Nyström L, Gunnarsson A, Eck E, Monson C, Geschwindner S, Snijder A, Höök F. Preserved transmembrane protein mobility in polymer-supported lipid bilayers derived from cell membranes. Anal Chem 2015; 87:9194-203. [PMID: 26268463 DOI: 10.1021/acs.analchem.5b01449] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Supported lipid bilayers (SLBs) have contributed invaluable information about the physiochemical properties of cell membranes, but their compositional simplicity often limits the level of knowledge that can be gained about the structure and function of transmembrane proteins in their native environment. Herein, we demonstrate a generic protocol for producing polymer-supported lipid bilayers on glass surfaces that contain essentially all naturally occurring cell-membrane components of a cell line while still retaining transmembrane protein mobility and activity. This was achieved by merging vesicles made from synthetic lipids (PEGylated lipids and POPC lipids) with native cell-membrane vesicles to generate hybrid vesicles which readily rupture into a continuous polymer-supported lipid bilayer. To investigate the properties of these complex hybrid SLBs and particularly the behavior of their integral membrane-proteins, we used total internal reflection fluorescence imaging to study a transmembrane protease, β-secretase 1 (BACE1), whose ectoplasmic and cytoplasmic domains could both be specifically targeted with fluorescent reporters. By selectively probing the two different orientations of BACE1 in the resulting hybrid SLBs, the role of the PEG-cushion on transmembrane protein lateral mobility was investigated. The results reveal the necessity of having the PEGylated lipids present during vesicle adsorption to prevent immobilization of transmembrane proteins with protruding domains. The proteolytic activity of BACE1 was unadulterated by the sonication process used to merge the synthetic and native membrane vesicles; importantly it was also conserved in the SLB. The presented strategy could thus serve both fundamental studies of membrane biophysics and the production of surface-based bioanalytical sensor platforms.
Collapse
Affiliation(s)
- Hudson Pace
- Department of Applied Physics, Chalmers University of Technology , SE-41296 Gothenburg, Sweden
| | - Lisa Simonsson Nyström
- Department of Applied Physics, Chalmers University of Technology , SE-41296 Gothenburg, Sweden
| | - Anders Gunnarsson
- Discovery Sciences, AstraZeneca R&D Mölndal , SE-43183 Mölndal, Sweden
| | - Elizabeth Eck
- Department of Applied Physics, Chalmers University of Technology , SE-41296 Gothenburg, Sweden
| | - Christopher Monson
- Department of Physical Science, Southern Utah University , Cedar City, Utah 84720 United States
| | | | - Arjan Snijder
- Discovery Sciences, AstraZeneca R&D Mölndal , SE-43183 Mölndal, Sweden
| | - Fredrik Höök
- Department of Applied Physics, Chalmers University of Technology , SE-41296 Gothenburg, Sweden
| |
Collapse
|
22
|
Reimhult E, Höök F. Design of surface modifications for nanoscale sensor applications. SENSORS (BASEL, SWITZERLAND) 2015; 15:1635-75. [PMID: 25594599 PMCID: PMC4327096 DOI: 10.3390/s150101635] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 01/07/2015] [Indexed: 02/07/2023]
Abstract
Nanoscale biosensors provide the possibility to miniaturize optic, acoustic and electric sensors to the dimensions of biomolecules. This enables approaching single-molecule detection and new sensing modalities that probe molecular conformation. Nanoscale sensors are predominantly surface-based and label-free to exploit inherent advantages of physical phenomena allowing high sensitivity without distortive labeling. There are three main criteria to be optimized in the design of surface-based and label-free biosensors: (i) the biomolecules of interest must bind with high affinity and selectively to the sensitive area; (ii) the biomolecules must be efficiently transported from the bulk solution to the sensor; and (iii) the transducer concept must be sufficiently sensitive to detect low coverage of captured biomolecules within reasonable time scales. The majority of literature on nanoscale biosensors deals with the third criterion while implicitly assuming that solutions developed for macroscale biosensors to the first two, equally important, criteria are applicable also to nanoscale sensors. We focus on providing an introduction to and perspectives on the advanced concepts for surface functionalization of biosensors with nanosized sensor elements that have been developed over the past decades (criterion (iii)). We review in detail how patterning of molecular films designed to control interactions of biomolecules with nanoscale biosensor surfaces creates new possibilities as well as new challenges.
Collapse
Affiliation(s)
- Erik Reimhult
- Institute for Biologically Inspired Materials, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Vienna, Muthgasse 11, A-1190 Vienna, Austria.
| | - Fredrik Höök
- Biological Physics, Department of Applied Physics, Chalmers University of Technology, Fysikgränd 3, SE-411 33 Göteborg, Sweden.
| |
Collapse
|
23
|
Hu SK, Chen YM, Chao L. Phase segregation of polymerizable lipids to construct filters for separating lipid-membrane-embedded species. BIOMICROFLUIDICS 2014; 8:052005. [PMID: 25332729 PMCID: PMC4189399 DOI: 10.1063/1.4895570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 09/02/2014] [Indexed: 05/04/2023]
Abstract
Supported lipid bilayer (SLB) platforms have been developed to transport and separate membrane-embedded species in the species' native bilayer environment. In this study, we used the phase segregation phenomenon of lipid mixtures containing a polymerizable diacetylene phospholipid, 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DiynePC), and a nonpolymerizable phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), to create filter barrier structures in SLBs. Upon exposing the phase segregated samples to UV light, the DiynePC-rich domains could become crosslinked and remain fixed on the surface of the support, while the DOPC-rich regions, where no crosslinking could happen, could be removed later by detergent washing, and thus became the void regions in the filter. During the filter fabrication process, we used the laminar flow configuration in a microfluidic channel to control the spatial locations of the feed region and filter region in the SLB. The flow in a microfluidic channel was also used to apply a strong hydrodynamic shear stress to the SLB to transport the membrane-embedded species from the feed region to the filter region. We varied the DiynePC/DOPC molar ratio from 60/40 to 80/20 to adjust the cutoff size of the filter barriers and used two model membrane-embedded species of different sizes to examine the filtering capability. One of the model species, Texas Red 1,2-dihexa-decanoyl-sn-glycero-3-phosphoethanolamine triethylammonium salt (Texas Red DHPE), had a single-lipid size, and the other species, cholera toxin subunit B-GM1 complex, had a multilipid size. When the DiynePC/DOPC molar ratio was 60/40, both species had high penetration ratios in the filter region. However, when the ratio was increased to 70/30, only the Texas Red DHPE, which was the smaller of the two model species, could penetrate the filter to a considerable extent. When the ratio was increased to 80/20, neither of the model species could penetrate the filter region. The results showed the possibility of using phase segregation of a mixture containing a polymerizable lipid and a nonpolymerizable lipid to fabricate filter barrier structures with tunable cutoff sizes in SLBs.
Collapse
Affiliation(s)
- Shu-Kai Hu
- Department of Chemical Engineering, National Taiwan University , No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Ya-Ming Chen
- Department of Chemical Engineering, National Taiwan University , No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Ling Chao
- Department of Chemical Engineering, National Taiwan University , No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
| |
Collapse
|
24
|
Peptide-membrane interactions of arginine-tryptophan peptides probed using quartz crystal microbalance with dissipation monitoring. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2014; 43:241-53. [PMID: 24743917 PMCID: PMC4053608 DOI: 10.1007/s00249-014-0958-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 03/20/2014] [Accepted: 03/31/2014] [Indexed: 11/11/2022]
Abstract
Membrane-active peptides include peptides that can cross cellular membranes and deliver macromolecular cargo as well as peptides that inhibit bacterial growth. Some of these peptides can act as both transporters and antibacterial agents. It is desirable to combine the knowledge from these two different fields of membrane-active peptides into design of new peptides with tailored actions, as transporters of cargo or as antibacterial substances, targeting specific membranes. We have previously shown that the position of the amino acid tryptophan in the peptide sequence of three arginine-tryptophan peptides affects their uptake and intracellular localization in live mammalian cells, as well as their ability to inhibit bacterial growth. Here, we use quartz crystal microbalance with dissipation monitoring to assess the induced changes caused by binding of the three peptides to supported model membranes composed of POPC, POPC/POPG, POPC/POPG/cholesterol or POPC/lactosyl PE. Our results indicate that the tryptophan position in the peptide sequence affects the way these peptides interact with the different model membranes and that the presence of cholesterol in particular seems to affect the membrane interaction of the peptide with an even distribution of tryptophans in the peptide sequence. These results give mechanistic insight into the function of these peptides and may aid in the design of membrane-active peptides with specified cellular targets and actions.
Collapse
|
25
|
Ainla A, Gözen I, Hakonen B, Jesorka A. Lab on a Biomembrane: rapid prototyping and manipulation of 2D fluidic lipid bilayers circuits. Sci Rep 2013; 3:2743. [PMID: 24067786 PMCID: PMC3783038 DOI: 10.1038/srep02743] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 08/28/2013] [Indexed: 11/11/2022] Open
Abstract
Lipid bilayer membranes are among the most ubiquitous structures in the living world, with intricate structural features and a multitude of biological functions. It is attractive to recreate these structures in the laboratory, as this allows mimicking and studying the properties of biomembranes and their constituents, and to specifically exploit the intrinsic two-dimensional fluidity. Even though diverse strategies for membrane fabrication have been reported, the development of related applications and technologies has been hindered by the unavailability of both versatile and simple methods. Here we report a rapid prototyping technology for two-dimensional fluidic devices, based on in-situ generated circuits of phospholipid films. In this "lab on a molecularly thin membrane", various chemical and physical operations, such as writing, erasing, functionalization, and molecular transport, can be applied to user-defined regions of a membrane circuit. This concept is an enabling technology for research on molecular membranes and their technological use.
Collapse
Affiliation(s)
- Alar Ainla
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296 Göteborg, Sweden
| | - Irep Gözen
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296 Göteborg, Sweden
- Current address: Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Bioengineering, Department of Medicine, Brigham and Women′s Hospital, Harvard Medical School, Boston, MA, USA
| | - Bodil Hakonen
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296 Göteborg, Sweden
| | - Aldo Jesorka
- Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 41296 Göteborg, Sweden
| |
Collapse
|
26
|
Hu SK, Hsiao SW, Mao HY, Chen YM, Chang Y, Chao L. Using crosslinkable diacetylene phospholipids to construct two-dimensional packed beds in supported lipid bilayer separation platforms. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2013; 14:044408. [PMID: 27877593 PMCID: PMC5090319 DOI: 10.1088/1468-6996/14/4/044408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 07/26/2013] [Indexed: 05/04/2023]
Abstract
Separating and purifying cell membrane-associated biomolecules has been a challenge owing to their amphiphilic property. Taking these species out of their native lipid membrane environment usually results in biomolecule degradation. One of the new directions is to use supported lipid bilayer (SLB) platforms to separate the membrane species while they are protected in their native environment. Here we used a type of crosslinkable diacetylene phospholipids, diynePC (1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine), as a packed material to create a 'two-dimensional (2D) packed bed' in a SLB platform. After the diynePC SLB is exposed to UV light, some of the diynePC lipids in the SLB can crosslink and the non-crosslinked monomer lipids can be washed away, leaving a 2D porous solid matrix. We incorporated the lipid vesicle deposition method with a microfluidic device to pattern the location of the packed-bed region and the feed region with species to be separated in a SLB platform. Our atomic force microscopy result shows that the nano-scaled structure density of the '2D packed bed' can be tuned by the UV dose applied to the diynePC membrane. When the model membrane biomolecules were forced to transport through the packed-bed region, their concentration front velocities were found to decrease linearly with the UV dose, indicating the successful creation of packed obstacles in these 2D lipid membrane separation platforms.
Collapse
Affiliation(s)
- Shu-Kai Hu
- Department of Chemical Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Sheng-Wen Hsiao
- R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Jhong-Li, Taoyuan 320, Taiwan
| | - Hsun-Yen Mao
- Department of Chemical Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Ya-Ming Chen
- Department of Chemical Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Yung Chang
- R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Jhong-Li, Taoyuan 320, Taiwan
| | - Ling Chao
- Department of Chemical Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
| |
Collapse
|
27
|
Chao L, Richards MJ, Hsia CY, Daniel S. Two-Dimensional Continuous Extraction in Multiphase Lipid Bilayers To Separate, Enrich, and Sort Membrane-Bound Species. Anal Chem 2013; 85:6696-702. [DOI: 10.1021/ac4006952] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Ling Chao
- School of Chemical and Biomolecular Engineering, Cornell University, 120 Olin Hall, Ithaca, New York
14853, United States
| | - Mark J. Richards
- School of Chemical and Biomolecular Engineering, Cornell University, 120 Olin Hall, Ithaca, New York
14853, United States
| | - Chih-Yun Hsia
- School of Chemical and Biomolecular Engineering, Cornell University, 120 Olin Hall, Ithaca, New York
14853, United States
| | - Susan Daniel
- School of Chemical and Biomolecular Engineering, Cornell University, 120 Olin Hall, Ithaca, New York
14853, United States
| |
Collapse
|
28
|
Schäffer TE. Nanomechanics of molecules and living cells with scanning ion conductance microscopy. Anal Chem 2013; 85:6988-94. [PMID: 23692368 DOI: 10.1021/ac400686k] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hydrodynamic flow through a nanopipet in a scanning ion conductance microscope (SICM) can exert localized forces on a sample surface. These forces can be used for trapping of molecules in lipid bilayers and for mapping the mechanical properties of living cells.
Collapse
Affiliation(s)
- Tilman E Schäffer
- University of Tübingen, Department of Physics and LISA+, Tübingen, Germany
| |
Collapse
|
29
|
Bao P, Cheetham MR, Roth JS, Blakeston AC, Bushby RJ, Evans SD. On-Chip Alternating Current Electrophoresis in Supported Lipid Bilayer Membranes. Anal Chem 2012; 84:10702-7. [DOI: 10.1021/ac302446w] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Peng Bao
- School of Physics and
Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Matthew R. Cheetham
- School of Physics and
Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Johannes S. Roth
- School of Physics and
Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Anita C. Blakeston
- School of Physics and
Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Richard J. Bushby
- School of Physics and
Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Stephen D. Evans
- School of Physics and
Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| |
Collapse
|
30
|
Gunnarsson A, Bally M, Jönsson P, Médard N, Höök F. Time-resolved surface-enhanced ellipsometric contrast imaging for label-free analysis of biomolecular recognition reactions on glycolipid domains. Anal Chem 2012; 84:6538-45. [PMID: 22803821 DOI: 10.1021/ac300832k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We have applied surface-enhanced ellipsometry contrast (SEEC) imaging for time-resolved label-free visualization of biomolecular recognition events on spatially heterogeneous supported lipid bilayers (SLB). Using a conventional inverted microscope equipped with total internal reflection (TIR) illumination, biomolecular binding events were monitored with a lateral resolution near the optical diffraction limit at an acquisition rate of ~1 Hz with a sensitivity in terms of surface coverage of ~1 ng/cm(2). Despite the significant improvement in spatial resolution compared to alternative label-free surface-based imaging technologies, the sensitivity remains competitive with surface plasmon resonance (SPR) imaging and imaging ellipsometry. The potential of the technique to discriminate local differences in protein binding kinetics was demonstrated by time-resolved imaging of anti-GalCer antibodies binding to phase-separated lipid bilayers consisting of phosphatidylcholine (POPC) and galactosylceramide (GalCer). A higher antibody binding capacity was observed on the GalCer-diluted fluid region in comparison to the GalCer-rich gel phase domains. This observation is tentatively attributed to differences in the presentation of the GalCer epitope in the two phases, resulting in differences in availability of the ligand for antibody binding. The complementary information obtained by swiftly switching between SEEC and fluorescence (including TIR fluorescence) imaging modes was used to support the data interpretation. The simplicity and generic applicability of the concept is discussed in terms of microfluidic applications.
Collapse
Affiliation(s)
- Anders Gunnarsson
- Department of Applied Physics, Division of Biological Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
| | | | | | | | | |
Collapse
|
31
|
Jönsson P, McColl J, Clarke RW, Ostanin VP, Jönsson B, Klenerman D. Hydrodynamic trapping of molecules in lipid bilayers. Proc Natl Acad Sci U S A 2012; 109:10328-33. [PMID: 22699491 PMCID: PMC3387037 DOI: 10.1073/pnas.1202858109] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this work we show how hydrodynamic forces can be used to locally trap molecules in a supported lipid bilayer (SLB). The method uses the hydrodynamic drag forces arising from a flow through a conical pipette with a tip radius of 1-1.5 μm, placed approximately 1 μm above the investigated SLB. This results in a localized forcefield that acts on molecules protruding from the SLB, yielding a hydrodynamic trap with a size approximately given by the size of the pipette tip. We demonstrate this concept by trapping the protein streptavidin, bound to biotin receptors in the SLB. It is also shown how static and kinetic information about the intermolecular interactions in the lipid bilayer can be obtained by relating how the magnitude of the hydrodynamic forces affects the accumulation of protein molecules in the trap.
Collapse
Affiliation(s)
- Peter Jönsson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom; and
| | - James McColl
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom; and
| | - Richard W. Clarke
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom; and
| | - Victor P. Ostanin
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom; and
| | - Bengt Jönsson
- Department of Biophysical Chemistry, Lund University, SE-22100 Lund, Sweden
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom; and
| |
Collapse
|
32
|
Nanofabrication for the analysis and manipulation of membranes. Ann Biomed Eng 2011; 40:1356-66. [PMID: 22143598 DOI: 10.1007/s10439-011-0479-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 11/23/2011] [Indexed: 12/21/2022]
Abstract
Recent advancements and applications of nanofabrication have enabled the characterization and control of biological membranes at submicron scales. This review focuses on the application of nanofabrication towards the nanoscale observing, patterning, sorting, and concentrating membrane components. Membranes on living cells are a necessary component of many fundamental cellular processes that naturally incorporate nanoscale rearrangement of the membrane lipids and proteins. Nanofabrication has advanced these understandings, for example, by providing 30 nm resolution of membrane proteins with metal-enhanced fluorescence at the tip of a scanning probe on fixed cells. Naturally diffusing single molecules at high concentrations on live cells have been observed at 60 nm resolution by confining the fluorescence excitation light through nanoscale metallic apertures. The lateral reorganization on the plasma membrane during membrane-mediated signaling processes has been examined in response to nanoscale variations in the patterning and mobility of the signal-triggering molecules. Further, membrane components have been separated, concentrated, and extracted through on-chip electrophoretic and microfluidic methods. Nanofabrication provides numerous methods for examining and manipulating membranes for both greater understandings of membrane processes as well as for the application of membranes to other biophysical methods.
Collapse
|
33
|
Kumar K, Isa L, Egner A, Schmidt R, Textor M, Reimhult E. Formation of nanopore-spanning lipid bilayers through liposome fusion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:10920-10928. [PMID: 21749115 DOI: 10.1021/la2019132] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Self-assembly of nanopore-spanning lipid bilayers (npsLBs) paves the way toward chip-based integrated membrane protein biosensing. We present a novel approach to analyze the formation of npsLB at individual nanopores using quantitative analysis of high-resolution microscopy images. From this analysis we derive necessary conditions for the formation of npsLBs on nanopore arrays by liposome fusion and discuss the limitations of the process as a function of nanopore geometry, lipid membrane properties, and surface interaction. Most importantly, applying liposomes with diameters larger than the nanopore is demonstrated to be a necessary but not sufficient condition for npsLB formation. A theoretical model is used to discuss and explain this experimental finding.
Collapse
Affiliation(s)
- Karthik Kumar
- Department of Materials, Laboratory for Surface Science and Technology, Swiss Federal Institute of Technology (ETH Zürich), CH-8093 Zürich, Switzerland
| | | | | | | | | | | |
Collapse
|
34
|
Simonsson L, Gunnarsson A, Wallin P, Jönsson P, Höök F. Continuous Lipid Bilayers Derived from Cell Membranes for Spatial Molecular Manipulation. J Am Chem Soc 2011; 133:14027-32. [DOI: 10.1021/ja204589a] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lisa Simonsson
- Department of Applied Physics, Chalmers University of Technology, SE 41296 Gothenburg, Sweden
| | - Anders Gunnarsson
- Department of Applied Physics, Chalmers University of Technology, SE 41296 Gothenburg, Sweden
| | - Patric Wallin
- Department of Applied Physics, Chalmers University of Technology, SE 41296 Gothenburg, Sweden
| | - Peter Jönsson
- Department of Applied Physics, Chalmers University of Technology, SE 41296 Gothenburg, Sweden
| | - Fredrik Höök
- Department of Applied Physics, Chalmers University of Technology, SE 41296 Gothenburg, Sweden
| |
Collapse
|
35
|
Cheetham MR, Bramble JP, McMillan DGG, Krzeminski L, Han X, Johnson BRG, Bushby RJ, Olmsted PD, Jeuken LJC, Marritt SJ, Butt JN, Evans SD. Concentrating Membrane Proteins Using Asymmetric Traps and AC Electric Fields. J Am Chem Soc 2011; 133:6521-4. [DOI: 10.1021/ja2007615] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthew R. Cheetham
- School of Physics & Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Jonathan P. Bramble
- School of Physics & Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Duncan G. G. McMillan
- School of Physics & Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
- Institute of Membrane and Systems Biology, University of Leeds, Leeds LS2 9JT, U.K
- Centre for Molecular Nanoscience, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Lukasz Krzeminski
- School of Physics & Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
- Centre for Molecular Nanoscience, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Xiaojun Han
- School of Physics & Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | | | - Richard J. Bushby
- Centre for Molecular Nanoscience, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Peter D. Olmsted
- School of Physics & Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Lars J. C. Jeuken
- School of Physics & Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
- Institute of Membrane and Systems Biology, University of Leeds, Leeds LS2 9JT, U.K
- Centre for Molecular Nanoscience, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Sophie J. Marritt
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Julea N. Butt
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Stephen D. Evans
- School of Physics & Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| |
Collapse
|
36
|
Jönsson P, Höök F. Effects of surface pressure and internal friction on the dynamics of shear-driven supported lipid bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1430-1439. [PMID: 21142022 DOI: 10.1021/la103959w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Supported lipid bilayers (SLBs) are one of the most common model systems for cell membrane studies. We have previously found that when applying a bulk flow of liquid above an SLB the lipid bilayer and its constituents move in the direction of the bulk flow in a rolling type of motion, with the lower monolayer being essentially stationary. In this study, a theoretical platform is developed to model the dynamic behavior of a shear-driven SLB. In most regions of the moving SLB, the dynamics of the lipid bilayer is well explained by a balance between the hydrodynamic shear force arising from the bulk flow above the lipid bilayer and the friction between the upper and lower monolayers of the SLB. These two forces result in a drift velocity profile for the lipids in the upper monolayer of the SLB that is highest at the center of the channel and decreases to almost zero at the corners of the channel. However, near the front of an advancing SLB a very different flow behavior is observed, showing an almost constant drift velocity of the lipids over the entire bilayer front. In this region, the motion of the SLB is significantly influenced by gradients in the surface pressure as well as internal friction due to molecules that have accumulated at the front of the SLB. It is shown that even a modest surface fraction of accumulated molecules (∼1%) can drastically affect the behavior of the SLB near the bilayer front, forcing the advancing lipids in the SLB away from the center of the channel out toward the sides.
Collapse
Affiliation(s)
- Peter Jönsson
- Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden.
| | | |
Collapse
|