1
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Carey AB, Ashenden A, Köper I. Model architectures for bacterial membranes. Biophys Rev 2022; 14:111-143. [PMID: 35340604 PMCID: PMC8921416 DOI: 10.1007/s12551-021-00913-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/14/2021] [Indexed: 02/06/2023] Open
Abstract
The complex composition of bacterial membranes has a significant impact on the understanding of pathogen function and their development towards antibiotic resistance. In addition to the inherent complexity and biosafety risks of studying biological pathogen membranes, the continual rise of antibiotic resistance and its significant economical and clinical consequences has motivated the development of numerous in vitro model membrane systems with tuneable compositions, geometries, and sizes. Approaches discussed in this review include liposomes, solid-supported bilayers, and computational simulations which have been used to explore various processes including drug-membrane interactions, lipid-protein interactions, host-pathogen interactions, and structure-induced bacterial pathogenesis. The advantages, limitations, and applicable analytical tools of all architectures are summarised with a perspective for future research efforts in architectural improvement and elucidation of resistance development strategies and membrane-targeting antibiotic mechanisms. Supplementary Information The online version contains supplementary material available at 10.1007/s12551-021-00913-7.
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Affiliation(s)
- Ashley B. Carey
- Institute for Nanoscale Science and Technology, College for Science and Engineering, Flinders University, Adelaide, SA 5042 Australia
| | - Alex Ashenden
- Institute for Nanoscale Science and Technology, College for Science and Engineering, Flinders University, Adelaide, SA 5042 Australia
| | - Ingo Köper
- Institute for Nanoscale Science and Technology, College for Science and Engineering, Flinders University, Adelaide, SA 5042 Australia
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2
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3
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Kihara S, Köper I, Mata JP, McGillivray DJ. Reviewing nanoplastic toxicology: It's an interface problem. Adv Colloid Interface Sci 2021; 288:102337. [PMID: 33385776 DOI: 10.1016/j.cis.2020.102337] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 01/19/2023]
Abstract
Multiple international agencies have recently raised environmental and health concerns regarding plastics in nanoforms (nanoplastics), but there is insufficient knowledge of their properties to allow for an accurate risk assessment to be conducted and any risks managed. For this reason, research into the toxicity of nanoplastics has focused strongly on documenting their impacts on biological organisms. One scope of this review is to summarise the recent findings on the adverse effects on biological organisms and strategies which can be adopted to advance our understanding of nanoplastic properties and their toxicity. Specifically, a mechanistic approach has already been employed in nanotoxicology, which focuses on the cause-and-effect relationships to establish a tool that predicts the biological impacts based on nanoparticle characteristics. Identifying the chemical and biological bases behind the observed biological effects (such as in vitro cellular response) is a major challenge, due to the intricate nature of nanoparticle-biological molecule complexes and an unawareness of their interaction with other biological targets, particularly at interfacial level. An exemplary case includes protein corona formation and ecological molecule corona (eco-corona) for nanoplastics. Therefore, the second scope of this review is to discuss recent findings and importance of (for both non-plastic and plastic nanoparticles) coronae formation and structure. Finally, we discuss the opportunities provided by model system approaches (model protein corona and lipid bilayer) to deepen the understanding of the above-mentioned perspectives, and corroborate the findings from in vitro experiments.
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Affiliation(s)
- Shinji Kihara
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand; The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Ingo Köper
- Institute for Nanoscale Science and Technology, College for Science and Engineering, Flinders University, Adelaide, SA 5042, Australia
| | - Jitendra P Mata
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, NSW 2234, Australia.
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand; The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
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4
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Application of N-methyl-D-aspartate receptor nanopore in screening ligand molecules. Bioelectrochemistry 2020; 134:107534. [PMID: 32335354 DOI: 10.1016/j.bioelechem.2020.107534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 04/08/2020] [Accepted: 04/08/2020] [Indexed: 11/20/2022]
Abstract
N-methyl-D-aspartate receptors (NMDARs) are crucial for excitatory synaptic transmission in the central nervous system. To study NMDARs more accurately and conveniently, we developed a stable NMDAR nanopore in a planar lipid bilayer. Pharmacological properties were validated using the allosteric modulator Ro 25-6981 and antagonist D-2-amino-5-phosphonopentanoic acid (D-APV). The cyanotoxin β-N-methylamino-L-alanine (BMAA) found in fresh water systems is suspected to be associated with the development of neurodegenerative diseases. Therefore, BMAA and its two isomers L-2, 4-Diaminobutyric acid dihydrochloride (DAB) and N-(2-aminoethyl) glycine (AEG) and an endogenous excitotoxin, quinolinic acid (QA), were studied using the NMDAR nanopores to assess their effects on NMDAR modulation. We demonstrated that the NMDAR nanopore could reliably detect its ligand molecules at the single-channel level. The study also demonstrated the practicability of NMDAR nanopores, and results were validated using two-electrode voltage-clamp (TEVC) recording. Compared with TEVC recording, the NMDAR nanopores conducted ion channel gating at the single-channel level without being affected by other proteins on the cell membrane. The highly sensitive and accurate NMDAR nanopore technique thus has a unique advantage in screening NMDAR ligand molecules that could be associated with neurodegenerative disease.
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5
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Alharbi ARM, Andersson JM, Köper I, Andersson GG. Investigating the Structure of Self-Assembled Monolayers Related to Biological Cell Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:14213-14221. [PMID: 31596586 DOI: 10.1021/acs.langmuir.9b02553] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Tethered bilayer lipid membranes are solid supported lipid membranes, where the inner leaflet is covalently linked to the solid supported substrate through anchorlipids. These anchorlipids form a self-assembled monolayer, which serves as the basis of the membrane and also provides submembrane space. The molecular structure and composition of this monolayer has thus significant influence on the membrane structural and functional properties. The density of the self-assembled monolayer can be tailored by adding small molecules to the monolayer. Here, the structure of fully tethered and sparsely tethered monolayers, where the anchorlipid has been diluted with a small surface-active thiol, has been analyzed using neutral impact collision ion scattering spectroscopy, X-ray photoelectron spectroscopy, and metastable induced electron spectroscopy. Combination of these three techniques allowed description of the self-assembly process in detail. The monolayers have been characterized in terms of layer thickness and orientation of the lipids.
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Affiliation(s)
| | - Jakob M Andersson
- Biosensor Technologies , Austrian Institute of Technology , 1210 Vienna , Austria
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6
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Squillace O, Esnault C, Pilard JF, Brotons G. Electrodes for Membrane Surface Science. Bilayer Lipid Membranes Tethered by Commercial Surfactants on Electrochemical Sensors. ACS Sens 2019; 4:1337-1345. [PMID: 30977639 DOI: 10.1021/acssensors.9b00267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Commercial surfactants, which are inexpensive and abundant, were covalently grafted to flat and transparent electrodes, and it appears to be a simple functionalization route to design biomembrane sensors at large-scale production. Sparsely tethered bilayer lipid membranes (stBLM) were stabilized using such molecular coatings composed of diluted anchor-harpoon surfactants that grab the membrane with an alkyl chain out of a PEGylated-hydrogel layer, which acts as a soft hydration cushion. The goal of avoiding the synthesis of complex organic molecules to scale up sensors was achieved here by grafting nonionic diblock oligomers (Brij58 = C xH2 x+1(OCH2CH2) nOH with x = 16 and n = 23) and PEO short chains ((OCH2CH2) nOH with n = 9 and n = 23) from their hydroxyl (-OH) end-moiety to a monolayer of -Ar-SO2Cl groups, which are easy to form on electrodes (metals, semiconducting materials, ...) from aryl-diazonium salt reduction. A hybrid molecular coating on gold, with scarce Ar-SO2-Brij58 and PEO oligomers, was used to monitor immobilization and fusion kinetics of DOPC small unilamellar vesicles (SUV) by both quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) techniques. Using flat and transparent thin chromium film electrodes, we designed biosensors to couple surface sensitive techniques for membranes, including X-ray reflectivity (XRR), atomic force microscopy (AFM) with subnanometer resolution, and optical microscopy, such as fluorescence recovery after photobleaching measurements (FRAP), in addition to electrochemistry techniques (cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS)). The advantages of this biomembrane-sensing platform are discussed for research and applications.
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Affiliation(s)
- Ophélie Squillace
- IMMM, Institut des Molécules et Matériaux du Mans, Le Mans Université—UFR Sciences et Techniques, Avenue Olivier Messiaen, 72085 Le Mans, France
| | - Charles Esnault
- IMMM, Institut des Molécules et Matériaux du Mans, Le Mans Université—UFR Sciences et Techniques, Avenue Olivier Messiaen, 72085 Le Mans, France
| | - Jean-François Pilard
- IMMM, Institut des Molécules et Matériaux du Mans, Le Mans Université—UFR Sciences et Techniques, Avenue Olivier Messiaen, 72085 Le Mans, France
| | - Guillaume Brotons
- IMMM, Institut des Molécules et Matériaux du Mans, Le Mans Université—UFR Sciences et Techniques, Avenue Olivier Messiaen, 72085 Le Mans, France
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7
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Chia C, Jeffrey SS, Howe RT. Scalable methods for ultra-smooth platinum in nanoscale devices. MICRO AND NANO ENGINEERING 2019. [DOI: 10.1016/j.mne.2019.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Penkauskas T, Preta G. Biological applications of tethered bilayer lipid membranes. Biochimie 2019; 157:131-141. [DOI: 10.1016/j.biochi.2018.11.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/19/2018] [Indexed: 12/16/2022]
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9
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Dhanasekaran M, Jaganathan M, Dhathathreyan A. Colloids versus solution state adsorption of proteins: Interaction of Myoglobin with supported lipid bilayers. Int J Biol Macromol 2018; 114:434-440. [PMID: 29555511 DOI: 10.1016/j.ijbiomac.2018.03.078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 03/16/2018] [Indexed: 11/15/2022]
Abstract
This study examines adsorption of Myoglobin (Mb) in solution and as colloid on supported lipid bilayers of neutral phospholipids and a mixture of neutral+cationic lipids formed on gold coated quartz in a Quartz crystal microbalance (QCM). Results indicate that thin adsorbed films of Mb in solution and as colloids, show atleast 3 steps in the interaction with the bilayers: i) An initial strain of a viscoelastic film ii) Entrained water that moves in and out of the adsorbed film and iii) The coupled load from the bulk liquid which increases the strain of the film. These three components constitute an effective viscoelastic film which is rigidly coupled to the QCM. Grazing incidence XRD (GIXD) shows that the bilayer head group remains nearly undisturbed for Mb solution with pure (neutral) and (neutral+cationic) mixtures, whereas for the colloids there is an increase in head group thickness with neutral and decrease in the case of mixture. Unsaturation in the alkyl tails in the neutral lipid resulting in flexible disordered bilayers and more entrained water in the cationic system results in these changes. The sensitivity of QCM-D, makes it useful to study real-time monitoring of bilayer structural robustness cytotoxicity, drug delivery and lipid self-assembly.
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Affiliation(s)
| | | | - A Dhathathreyan
- Advanced Materials Lab., CSIR-CLRI, Adyar, Chennai 600020, India.
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10
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Andersson J, Fuller MA, Wood K, Holt SA, Köper I. A tethered bilayer lipid membrane that mimics microbial membranes. Phys Chem Chem Phys 2018; 20:12958-12969. [DOI: 10.1039/c8cp01346b] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This work presents a self-assembled lipid bilayer architecture mimicking the outer membrane of Gram negative bacteria.
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Affiliation(s)
- Jakob Andersson
- Flinders Centre for Nanoscale Science and Technology and College of Science and Engineering
- Flinders University
- Adelaide
- Australia
| | - Melanie A. Fuller
- Flinders Centre for Nanoscale Science and Technology and College of Science and Engineering
- Flinders University
- Adelaide
- Australia
| | - Kathleen Wood
- Australian Centre for Neutron Scattering
- Australian Nuclear Science and Technology Organisation
- Kirrawee DC
- Australia
| | - Stephen A. Holt
- Australian Centre for Neutron Scattering
- Australian Nuclear Science and Technology Organisation
- Kirrawee DC
- Australia
| | - Ingo Köper
- Flinders Centre for Nanoscale Science and Technology and College of Science and Engineering
- Flinders University
- Adelaide
- Australia
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11
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Skalová Š, Vyskočil V, Barek J, Navrátil T. Model Biological Membranes and Possibilities of Application of Electrochemical Impedance Spectroscopy for their Characterization. ELECTROANAL 2017. [DOI: 10.1002/elan.201700649] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Štěpánka Skalová
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences; Dolejškova 3 182 23 Prague 8 Czech Republic
- Charles University; Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry; Hlavova 2030/8 128 43 Prague 2 Czech Republic
| | - Vlastimil Vyskočil
- Charles University; Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry; Hlavova 2030/8 128 43 Prague 2 Czech Republic
| | - Jiří Barek
- Charles University; Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry; Hlavova 2030/8 128 43 Prague 2 Czech Republic
| | - Tomáš Navrátil
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences; Dolejškova 3 182 23 Prague 8 Czech Republic
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12
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Zhou S, Schlipf DM, Guilfoil EC, Rankin SE, Knutson BL. Lipid Pore-Filled Silica Thin-Film Membranes for Biomimetic Recovery of Dilute Carbohydrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:14156-14166. [PMID: 29131638 DOI: 10.1021/acs.langmuir.7b03844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Selectively permeable biological membranes containing lipophilic barriers inspire the design of biomimetic carrier-mediated membranes for aqueous solute separation. The recovery of glucose, which can reversibly bind to boronic acid (BA) carriers, is examined in lipid pore-filled silica thin-film composite membranes with accessible mesopores. The successful incorporation of lipids (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) and BA carriers (4-((N-Boc-amino)methyl)phenylboronic acid, BAMP-BA) in the pores of mesoporous silica (∼10 nm pore diameter) through evaporation deposition is verified by confocal microscopy and differential scanning calorimetry. In the absence of BA carriers, lipids confined inside the pores of silica thin films (∼200 nm thick) provide a factor of 14 increase in diffusive transport resistance to glucose, relative to traditional supported lipid bilayers formed by vesicle fusion on the porous surface. The addition of lipid-immobilized BAMP-BA (59 mol % in DPPC) facilitates the transport of glucose through the membrane; glucose flux increases from 45 × 10-8 to 225 × 10-8 mol/m2/s in the presence of BAMP-BA. Furthermore, the transport can be improved by environmental factors including pH gradient (to control the binding and release of glucose) and temperature (to adjust lipid bilayer fluidity). The successful development of biomimetic nanocomposite membranes demonstrated here is an important step toward the efficient dilute aqueous solute upgrading or separations, such as the processing of carbohydrates from lignocellulose hydrolysates, using engineered carrier/catalyst/support systems.
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Affiliation(s)
- Shanshan Zhou
- Department of Chemical and Materials Engineering, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Daniel M Schlipf
- Department of Chemical and Materials Engineering, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Emma C Guilfoil
- Department of Chemical and Materials Engineering, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Stephen E Rankin
- Department of Chemical and Materials Engineering, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Barbara L Knutson
- Department of Chemical and Materials Engineering, University of Kentucky , Lexington, Kentucky 40506, United States
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13
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Diamanti E, Gutiérrez-Pineda E, Politakos N, Andreozzi P, Rodriguez-Presa MJ, Knoll W, Azzaroni O, Gervasi CA, Moya SE. Gramicidin ion channels in a lipid bilayer supported on polyelectrolyte multilayer films: an electrochemical impedance study. SOFT MATTER 2017; 13:8922-8929. [PMID: 29143830 DOI: 10.1039/c7sm01539a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Supported membranes on polymer cushions are of fundamental interest as models for cell membranes. The use of polyelectrolyte multilayers (PEMs) assembled by the layer by layer (LbL) technique as supports for a bilayer allows for easy integration of the lipid bilayer on surfaces and devices and for nanoscale tunable spacing of the lipid bilayer. Controlling ionic permeability in lipid bilayers supported on PEMs triggers potential applications in sensing and as models for transport phenomena in cell membranes. Lipid bilayers displaying gramicidin channels are fabricated on top of polyallylamine hydrochloride (PAH) and polystyrene sulfonate (PSS) multilayer films, by the assembly of vesicles of phosphatidylcholine and phosphatidylserine, 50 : 50 M/M, carrying gramicidin (GA). Quartz crystal microbalance with dissipation shows that the vesicles with GA fuse into a bilayer. Atomic force microscopy reveals that the presence of GA alters the bilayer topography resulting in depressions in the bilayer of around 70 nm in diameter. Electrochemical impedance spectroscopy (EIS) studies show that supported bilayers carrying GA have smaller resistances than the bilayers without GA. Lipid layers carrying GA display a higher conductance for K+ than for Na+ and are blocked in the presence of Ca2+.
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Affiliation(s)
- Eleftheria Diamanti
- Soft Matter Nanotechnology Group, CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastián, Guipúzcoa, Spain.
| | - Eduart Gutiérrez-Pineda
- Instituto de Investigaciones, Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, CONICET, Sucursal 4-C.C.16, 1900 La Plata, Argentina. and Area Electroquímica, Facultad de Ingeniería, Universidad Nacional de La Plata, calle 1 y 47, 1900 La Plata, Argentina
| | - Nikolaos Politakos
- Soft Matter Nanotechnology Group, CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastián, Guipúzcoa, Spain.
| | - Patrizia Andreozzi
- Soft Matter Nanotechnology Group, CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastián, Guipúzcoa, Spain.
| | - María José Rodriguez-Presa
- Instituto de Investigaciones, Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, CONICET, Sucursal 4-C.C.16, 1900 La Plata, Argentina.
| | - Wolfgang Knoll
- AIT Austrian Institute of Technology, Vienna, and CEST Competence Center for Electrochemical Surface Technology, Wiener Neustadt, Austria
| | - Omar Azzaroni
- Instituto de Investigaciones, Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, CONICET, Sucursal 4-C.C.16, 1900 La Plata, Argentina.
| | - Claudio A Gervasi
- Instituto de Investigaciones, Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, CONICET, Sucursal 4-C.C.16, 1900 La Plata, Argentina. and Area Electroquímica, Facultad de Ingeniería, Universidad Nacional de La Plata, calle 1 y 47, 1900 La Plata, Argentina
| | - Sergio E Moya
- Soft Matter Nanotechnology Group, CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastián, Guipúzcoa, Spain.
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Chiappisi L. Polyoxyethylene alkyl ether carboxylic acids: An overview of a neglected class of surfactants with multiresponsive properties. Adv Colloid Interface Sci 2017; 250:79-94. [PMID: 29056232 DOI: 10.1016/j.cis.2017.10.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/07/2017] [Accepted: 10/10/2017] [Indexed: 12/14/2022]
Abstract
In this work, an overview on aqueous solutions of polyoxyethylene alkyl ether carboxylic acids is given. Unique properties arise from the combination of the nonionic, temperature-responsive polyoxyethylene block with the weakly ionic, pH-responsive carboxylic acid termination in a single surfactant headgroup. Accordingly, this class of surfactant finds broad application across very different sectors. Despite their large use on an industrial and a technical scale, the literature lacks a systematic and detailed characterization of their physico-chemical properties which is provided herein. In addition, a comprehensive overview is given of their self-assembly and interfacial behavior, of their use as colloidal building blocks and for large-scale applications.
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Affiliation(s)
- Leonardo Chiappisi
- Technische Universität Berlin, Stranski Laboratorium für Physikalische Chemie und Theoretische Chemie, Institut für Chemie, Straße des 17. Juni 124, Sekr. TC7, D-10623 Berlin, Germany; Institut Max von Laue - Paul Langevin, Large Scale Structures Group, 71 avenue des Martyrs, Grenoble Cedex 9 38042, France.
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15
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Chadli M, Rebaud S, Maniti O, Tillier B, Cortès S, Girard-Egrot A. New Tethered Phospholipid Bilayers Integrating Functional G-Protein-Coupled Receptor Membrane Proteins. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:10385-10401. [PMID: 28877444 DOI: 10.1021/acs.langmuir.7b01636] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Membrane proteins exhibiting extra- and intracellular domains require an adequate near-native lipid platform for their functional reconstitution. With this aim, we developed a new technology enabling the formation of a peptide-tethered bilayer lipid membrane (pep-tBLM), a lipid bilayer grafted onto peptide spacers, by way of a metal-chelate interaction. To this end, we designed an original peptide spacer derived from the natural α-laminin thiopeptide (P19) possessing a cysteine residue in the N-terminal extremity for grafting onto gold and a C-terminal extremity modified by four histidine residues (P19-4H). In the presence of nickel, the use of this anchor allowed us to bind liposomes of variable compositions containing a 2% molar ratio of a chelating lipid, 1,2-dioleoyl-sn-glycero-3-[(N-(5-amino-1-carboxypentyl)iminodiacetic acid)succinyl] so-called DOGS-NTA, and to form the planar bilayer by triggering liposome fusion by an α-helical (AH) peptide derived from the N-terminus of the hepatitis C virus NS5A protein. The formation of pep-tBLMs was characterized by surface plasmon resonance imaging (SPRi), and their continuity, fluidity, and homogeneity were demonstrated by fluorescence recovery after photobleaching (FRAP), with a diffusion coefficient of 2.5 × 10-7 cm2/s, and atomic force microscopy (AFM). By using variable lipid compositions including phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylinositol 4,5-bisphosphate (PIP2), sphingomyelin (SM), phosphatidic acid (PA), and cholesterol (Chol) in various ratios, we show that the membrane can be formed independently from the lipid composition. We made the most of this advantage to reincorporate a transmembrane protein in an adapted complex lipid composition to ensure its functional reinsertion. For this purpose, a cell-free expression system was used to produce proteoliposomes expressing the functional C-X-C motif chemokine receptor 4 (CXCR4), a seven-transmembrane protein belonging to the large superfamily of G-protein-coupled receptors (GPCRs). We succeeded in reinserting CXCR4 in pep-tBLMs formed on P19-4H by the fusion of tethered proteoliposomes. AFM and FRAP characterization allowed us to show that pep-tBLMs inserting CXCR4 remained fluid, homogeneous, and continuous. The value of the diffusion coefficient determined in the presence of reinserted CXCR4 was 2 × 10-7 cm2/s. Ligand binding assays using a synthetic CXCR4 antagonist, T22 ([Tyr5,12, Lys7]-polyphemusin II), revealed that CXCR4 can be reinserted in pep-tBLMs with functional folding and orientation. This new approach represents a method of choice for investigating membrane protein reincorporation and a promising way of creating a new generation of membrane biochips adapted for screening agonists or antagonists of transmembrane proteins.
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Affiliation(s)
- Meriem Chadli
- Univ Lyon, Université Lyon 1 , Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, ICBMS, UMR CNRS 5246, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne, France
- Synthelis, Biopolis, 5, Avenue du Grand Sablon, 38700 La Tronche, France
| | - Samuel Rebaud
- Univ Lyon, Université Lyon 1 , Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, ICBMS, UMR CNRS 5246, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne, France
| | - Ofelia Maniti
- Univ Lyon, Université Lyon 1 , Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, ICBMS, UMR CNRS 5246, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne, France
| | - Bruno Tillier
- Synthelis, Biopolis, 5, Avenue du Grand Sablon, 38700 La Tronche, France
| | - Sandra Cortès
- Synthelis, Biopolis, 5, Avenue du Grand Sablon, 38700 La Tronche, France
| | - Agnès Girard-Egrot
- Univ Lyon, Université Lyon 1 , Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, ICBMS, UMR CNRS 5246, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne, France
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16
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Lipid bilayer membrane technologies: A review on single-molecule studies of DNA sequencing by using membrane nanopores. Mikrochim Acta 2017. [DOI: 10.1007/s00604-017-2321-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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17
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Andersson J, Knobloch JJ, Perkins MV, Holt SA, Köper I. Synthesis and Characterization of Novel Anchorlipids for Tethered Bilayer Lipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:4444-4451. [PMID: 28387116 DOI: 10.1021/acs.langmuir.7b00778] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Tethered bilayer lipid membranes are versatile solid-supported model membrane systems. Core to these systems is an anchorlipid that covalently links a lipid bilayer to a support. The molecular structure of these lipids can have a significant impact on the properties of the resulting bilayer. Here, the synthesis of anchorlipids containing ester groups in the tethering part is described. The lipids are used to form bilayer membranes, and the resulting structures are compared with membranes formed using conventional anchorlipids or sparsely tethered membranes. All membranes showed good electrical sealing properties; the disulphide-terminated anchorlipids could be used in a sparsely tethered system without significantly reducing the sealing properties of the lipid bilayers. The sparsely tethered systems also allowed for higher ion transport across the membrane, which is in good correlation with higher hydration of the spacer region as seen by neutron scattering.
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Affiliation(s)
- Jakob Andersson
- Flinders Centre for Nanoscalce Science and Technology and School of Chemical and Physical Sciences, Flinders University , Adelaide 5042, Australia
| | - Jacqueline J Knobloch
- Flinders Centre for Nanoscalce Science and Technology and School of Chemical and Physical Sciences, Flinders University , Adelaide 5042, Australia
| | - Michael V Perkins
- Flinders Centre for Nanoscalce Science and Technology and School of Chemical and Physical Sciences, Flinders University , Adelaide 5042, Australia
| | - Stephen A Holt
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation , Locked Bag 2001, Kirrawee DC, New South Wales 2234, Australia
| | - Ingo Köper
- Flinders Centre for Nanoscalce Science and Technology and School of Chemical and Physical Sciences, Flinders University , Adelaide 5042, Australia
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18
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Chung S, Noh HB, Shim YB. Thrombin Detection with Tetrabromophenolphthalein Ethyl Ester Adsorbed on Aptamer-attached Conductive Polymer. JOURNAL OF THE KOREAN ELECTROCHEMICAL SOCIETY 2016. [DOI: 10.5229/jkes.2016.19.4.134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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19
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Bronder AM, Bieker A, Elter S, Etzkorn M, Häussinger D, Oesterhelt F. Oriented Membrane Protein Reconstitution into Tethered Lipid Membranes for AFM Force Spectroscopy. Biophys J 2016; 111:1925-1934. [PMID: 27806274 PMCID: PMC5103026 DOI: 10.1016/j.bpj.2016.08.051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 08/21/2016] [Accepted: 08/22/2016] [Indexed: 12/11/2022] Open
Abstract
Membrane proteins act as a central interface between the extracellular environment and the intracellular response and as such represent one of the most important classes of drug targets. The characterization of the molecular properties of integral membrane proteins, such as topology and interdomain interaction, is key to a fundamental understanding of their function. Atomic force microscopy (AFM) and force spectroscopy have the intrinsic capabilities of investigating these properties in a near-native setting. However, atomic force spectroscopy of membrane proteins is traditionally carried out in a crystalline setup. Alternatively, model membrane systems, such as tethered bilayer membranes, have been developed for surface-dependent techniques. While these setups can provide a more native environment, data analysis may be complicated by the normally found statistical orientation of the reconstituted protein in the model membrane. We have developed a model membrane system that enables the study of membrane proteins in a defined orientation by single-molecule force spectroscopy. Our approach is demonstrated using cell-free expressed bacteriorhodopsin coupled to a quartz glass surface in a defined orientation through a protein anchor and reconstituted inside an artificial membrane system. This approach offers an effective way to study membrane proteins in a planar lipid bilayer. It can be easily transferred to all membrane proteins that possess a suitable tag and can be reconstituted into a lipid bilayer. In this respect, we anticipate that this technique may contribute important information on structure, topology, and intra- and intermolecular interactions of other seven-transmembrane helical receptors.
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Affiliation(s)
- Anna M Bronder
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Düsseldorf, Germany.
| | - Adeline Bieker
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Shantha Elter
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Manuel Etzkorn
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich-Heine-Universität, Düsseldorf, Germany
| | - Filipp Oesterhelt
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Düsseldorf, Germany; Department for Microbial Bioactive Compounds, Interfaculty Institute for Microbiology and Infection Medicine, University of Tuebingen, Tuebingen, Germany
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20
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Frey C, Eifert A, Schütz H, Barth H, Mizaikoff B, Kranz C. Macroscopic and microscopic electrochemical investigation of Clostridium botulinum C2IIa embedded in supported lipid membranes. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.05.055] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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21
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Andersson J, Köper I. Tethered and Polymer Supported Bilayer Lipid Membranes: Structure and Function. MEMBRANES 2016; 6:E30. [PMID: 27249006 PMCID: PMC4931525 DOI: 10.3390/membranes6020030] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 05/24/2016] [Accepted: 05/25/2016] [Indexed: 11/30/2022]
Abstract
Solid supported bilayer lipid membranes are model systems to mimic natural cell membranes in order to understand structural and functional properties of such systems. The use of a model system allows for the use of a wide variety of analytical tools including atomic force microscopy, impedance spectroscopy, neutron reflectometry, and surface plasmon resonance spectroscopy. Among the large number of different types of model membranes polymer-supported and tethered lipid bilayers have been shown to be versatile and useful systems. Both systems consist of a lipid bilayer, which is de-coupled from an underlying support by a spacer cushion. Both systems will be reviewed, with an emphasis on the effect that the spacer moiety has on the bilayer properties.
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Affiliation(s)
- Jakob Andersson
- Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Adelaide SA 5001, Australia.
| | - Ingo Köper
- Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Adelaide SA 5001, Australia.
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22
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Zieleniecki JL, Nagarajan Y, Waters S, Rongala J, Thompson V, Hrmova M, Köper I. Cell-Free Synthesis of a Functional Membrane Transporter into a Tethered Bilayer Lipid Membrane. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:2445-2449. [PMID: 26910192 DOI: 10.1021/acs.langmuir.5b04059] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Eukaryotic cell-free synthesis was used to incorporate the large and complex multispan plant membrane transporter Bot1 in a functional form into a tethered bilayer lipid membrane. The electrical properties of the protein-functionalized tethered bilayer were measured using electrochemical impedance spectroscopy and revealed a pH-dependent transport of borate ions through the protein. The efficacy of the protein synthesis has been evaluated using immunoblot analysis.
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Affiliation(s)
- Julius L Zieleniecki
- Flinders Centre for Nanoscale Science and Technology School of Chemical and Physical Sciences, Flinders University , Bedford Park, South Australia 5042, Australia
| | - Yagnesh Nagarajan
- Australian Centre for Plant Functional Genomics School of Agriculture, Food, and Wine, University of Adelaide , Glen Osmond, South Australia 5064, Australia
| | - Shane Waters
- Australian Centre for Plant Functional Genomics School of Agriculture, Food, and Wine, University of Adelaide , Glen Osmond, South Australia 5064, Australia
| | - Jay Rongala
- Australian Centre for Plant Functional Genomics School of Agriculture, Food, and Wine, University of Adelaide , Glen Osmond, South Australia 5064, Australia
| | - Vanessa Thompson
- Flinders Centre for Nanoscale Science and Technology School of Chemical and Physical Sciences, Flinders University , Bedford Park, South Australia 5042, Australia
| | - Maria Hrmova
- Australian Centre for Plant Functional Genomics School of Agriculture, Food, and Wine, University of Adelaide , Glen Osmond, South Australia 5064, Australia
| | - Ingo Köper
- Flinders Centre for Nanoscale Science and Technology School of Chemical and Physical Sciences, Flinders University , Bedford Park, South Australia 5042, Australia
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23
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Diamanti E, Andreozzi P, Anguiano R, Yate L, Gregurec D, Politakos N, Ziolo RF, Donath E, Moya SE. The effect of top-layer chemistry on the formation of supported lipid bilayers on polyelectrolyte multilayers: primary versus quaternary amines. Phys Chem Chem Phys 2016; 18:32396-32405. [DOI: 10.1039/c6cp06258j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The influence of the surface chemistry of PEMs on the formation of lipid bilayers is studied here for PEMs with different cationic amines as a top layer, and polystyrene sulfonate (PSS) as a polyanion.
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Affiliation(s)
- E. Diamanti
- Soft Matter Nanotechnology Group
- CIC biomaGUNE
- 20009 San Sebastián
- Spain
| | - P. Andreozzi
- Soft Matter Nanotechnology Group
- CIC biomaGUNE
- 20009 San Sebastián
- Spain
| | - R. Anguiano
- Departamento de Materiales Avanzados
- Centro de Investigación en Química Aplicada
- 25250 Saltillo
- Mexico
| | - L. Yate
- Soft Matter Nanotechnology Group
- CIC biomaGUNE
- 20009 San Sebastián
- Spain
| | - D. Gregurec
- Soft Matter Nanotechnology Group
- CIC biomaGUNE
- 20009 San Sebastián
- Spain
| | - N. Politakos
- Soft Matter Nanotechnology Group
- CIC biomaGUNE
- 20009 San Sebastián
- Spain
| | - R. F. Ziolo
- Departamento de Materiales Avanzados
- Centro de Investigación en Química Aplicada
- 25250 Saltillo
- Mexico
| | - E. Donath
- Institute of Biophysics and Medical Physics
- Faculty of Medicine
- University of Leipzig
- 04107 Leipzig
- Germany
| | - S. E. Moya
- Soft Matter Nanotechnology Group
- CIC biomaGUNE
- 20009 San Sebastián
- Spain
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24
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Almeida I, Marquês J, Liu W, Niu Y, de Almeida R, Jin G, Viana A. Phospholipid/cholesterol/decanethiol mixtures for direct assembly of immunosensing interfaces. Colloids Surf B Biointerfaces 2015; 136:997-1003. [DOI: 10.1016/j.colsurfb.2015.10.048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/13/2015] [Accepted: 10/29/2015] [Indexed: 12/20/2022]
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25
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Knobloch J, Suhendro DK, Zieleniecki JL, Shapter JG, Köper I. Membrane-drug interactions studied using model membrane systems. Saudi J Biol Sci 2015; 22:714-8. [PMID: 26586998 PMCID: PMC4625119 DOI: 10.1016/j.sjbs.2015.03.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 03/17/2015] [Accepted: 03/19/2015] [Indexed: 11/04/2022] Open
Abstract
The direct interaction of drugs with the cell membrane is often neglected when drug effects are studied. Systematic investigations are hindered by the complexity of the natural membrane and model membrane systems can offer a useful alternative. Here some examples are reviewed of how model membrane architectures including vesicles, Langmuir monolayers and solid supported membranes can be used to investigate the effects of drug molecules on the membrane structure, and how these interactions can translate into effects on embedded membrane proteins.
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Affiliation(s)
| | | | | | | | - Ingo Köper
- Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Adelaide, Australia
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26
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Goreham RV, Thompson VC, Samura Y, Gibson CT, Shapter JG, Köper I. Interaction of silver nanoparticles with tethered bilayer lipid membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:5868-5874. [PMID: 25950498 DOI: 10.1021/acs.langmuir.5b00586] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Silver nanoparticles are well-known for their antibacterial properties. However, the detailed mechanism describing the interaction between the nanoparticles and a cell membrane is not fully understood, which can impede the use of the particles in biomedical applications. Here, a tethered bilayer lipid membrane has been used as a model system to mimic a natural membrane and to study the effect of exposure to small silver nanoparticles with diameters of about 2 nm. The solid supported membrane architecture allowed for the application of surface analytical techniques such as electrochemical impedance spectroscopy and atomic force microscopy. Exposure of the membrane to solutions of the silver nanoparticles led to a small but completely reversible perturbation of the lipid bilayer.
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Affiliation(s)
- Renee V Goreham
- Flinders Centre for NanoScale Science and Technology and School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA, Australia 5042
| | - Vanessa C Thompson
- Flinders Centre for NanoScale Science and Technology and School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA, Australia 5042
| | - Yuya Samura
- Flinders Centre for NanoScale Science and Technology and School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA, Australia 5042
| | - Christopher T Gibson
- Flinders Centre for NanoScale Science and Technology and School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA, Australia 5042
| | - Joseph G Shapter
- Flinders Centre for NanoScale Science and Technology and School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA, Australia 5042
| | - Ingo Köper
- Flinders Centre for NanoScale Science and Technology and School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA, Australia 5042
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27
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Heinrich F, Lösche M. Zooming in on disordered systems: neutron reflection studies of proteins associated with fluid membranes. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1838:2341-9. [PMID: 24674984 PMCID: PMC4082750 DOI: 10.1016/j.bbamem.2014.03.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 03/13/2014] [Accepted: 03/17/2014] [Indexed: 11/23/2022]
Abstract
Neutron reflectometry (NR) is an emerging experimental technique for the structural characterization of proteins interacting with fluid bilayer membranes under conditions that mimic closely the cellular environment. Thus, cellular processes can be emulated in artificial systems and their molecular basis studied by adding cellular components one at a time in a well-controlled environment while the resulting structures, or structural changes in response to external cues, are monitored with neutron reflection. In recent years, sample environments, data collection strategies and data analysis were continuously refined. The combination of these improvements increases the information which can be obtained from NR to an extent that enables structural characterization of protein-membrane complexes at a length scale that exceeds the resolution of the measurement by far. Ultimately, the combination of NR with molecular dynamics (MD) simulations can be used to cross-validate the results of the two techniques and provide atomic-scale structural models. This review discusses these developments in detail and demonstrates how they provide new windows into relevant biomedical problems. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova.
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Affiliation(s)
- Frank Heinrich
- Physics Department, Carnegie Mellon University, Pittsburgh, PA, U.S.A.; NIST Center for Neutron Research, Gaithersburg, MD, U.S.A
| | - Mathias Lösche
- Physics Department, Carnegie Mellon University, Pittsburgh, PA, U.S.A.; NIST Center for Neutron Research, Gaithersburg, MD, U.S.A..
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28
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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]
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29
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Shadiac N, Nagarajan Y, Waters S, Hrmova M. Close allies in membrane protein research: Cell-free synthesis and nanotechnology. Mol Membr Biol 2013; 30:229-45. [DOI: 10.3109/09687688.2012.762125] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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30
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Biomimetic membrane platform: fabrication, characterization and applications. Colloids Surf B Biointerfaces 2012; 103:510-6. [PMID: 23261574 DOI: 10.1016/j.colsurfb.2012.10.066] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 10/20/2012] [Accepted: 10/24/2012] [Indexed: 11/24/2022]
Abstract
A facile method for assembly of biomimetic membranes serving as a platform for expression and insertion of membrane proteins is described. The membrane architecture was constructed in three steps: (i) assembly/printing of α-laminin peptide (P19) spacer on gold to separate solid support from the membrane architecture; (ii) covalent coupling of different lipid anchors to the P19 layer to serve as stabilizers of the inner leaflet during bilayer formation; (iii) lipid vesicle spreading to form a complete bilayer. Two different lipid membrane systems were examined and two different P19 architectures prepared by either self-assembly or μ-contact printing were tested and characterized using contact angle (CA) goniometry, surface plasmon resonance (SPR) spectroscopy and imaging surface plasmon resonance (iSPR). It is shown that surface coverage of cushion layer is significantly improved by μ-contact printing thereby facilitating bilayer formation as compared to self-assembly. To validate applicability of proposed methodology, incorporation of Cytochrome bo(3) ubiquinol oxidase (Cyt-bo(3)) into biomimetic membrane was performed by in vitro expression technique which was further monitored by surface plasmon enhanced fluorescence spectroscopy (SPFS). The results showed that solid supported planar membranes, tethered by α-laminin peptide cushion layer, provide an attractive environment for membrane protein insertion and characterization.
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31
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Abstract
Lipid bilayers are natural barriers of biological cells and cellular compartments. Membrane proteins integrated in biological membranes enable vital cell functions such as signal transduction and the transport of ions or small molecules. In order to determine the activity of a protein of interest at defined conditions, the membrane protein has to be integrated into artificial lipid bilayers immobilized on a surface. For the fabrication of such biosensors expertise is required in material science, surface and analytical chemistry, molecular biology and biotechnology. Specifically, techniques are needed for structuring surfaces in the micro- and nanometer scale, chemical modification and analysis, lipid bilayer formation, protein expression, purification and solubilization, and most importantly, protein integration into engineered lipid bilayers. Electrochemical and optical methods are suitable to detect membrane activity-related signals. The importance of structural knowledge to understand membrane protein function is obvious. Presently only a few structures of membrane proteins are solved at atomic resolution. Functional assays together with known structures of individual membrane proteins will contribute to a better understanding of vital biological processes occurring at biological membranes. Such assays will be utilized in the discovery of drugs, since membrane proteins are major drug targets.
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32
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Nanopore sensors: From hybrid to abiotic systems. Biosens Bioelectron 2012; 38:1-10. [DOI: 10.1016/j.bios.2012.05.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 05/02/2012] [Accepted: 05/12/2012] [Indexed: 11/22/2022]
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33
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Afanasenkau D, Offenhäusser A. Positively charged supported lipid bilayers as a biomimetic platform for neuronal cell culture. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:13387-13394. [PMID: 22920161 DOI: 10.1021/la302500r] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The supported lipid bilayer (SLB) is a well-known system for studying the cell membrane and membrane proteins. It is also promising as a platform for studying cell processes: the cell adhesion, the cell membrane receptors, and the intercellular signaling processes. SLBs made of natural lipids appeared to be protein and cell repellent. Thus, to use the SLB as a substrate for cells, one should functionalize them to provide adhesion. In the present paper, we describe a simple approach to promote adhesion of neuronal cells to the SLB without using proteins or peptides, by introducing positively charged lipids 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) into the SLB made of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). We show that neurons adhere to these bilayers and grow for at least 10 days. The SLBs themselves were found to degrade with time in cell culture conditions, but maintained fluidity (as revealed by fluorescence recovery after photobleaching), demonstrating the possibility of using SLBs for studying neuronal cells in culture.
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Affiliation(s)
- Dzmitry Afanasenkau
- Peter Grünberg Institute/Institute of Complex Systems Bioelectronics (PGI-8/ICS-8), Research Center Juelich, D-52425 Juelich, Germany
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34
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Vogel N, Zieleniecki J, Köper I. As flat as it gets: ultrasmooth surfaces from template-stripping procedures. NANOSCALE 2012; 4:3820-32. [PMID: 22628064 DOI: 10.1039/c2nr30434a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In an experimentally simple replica process, the natural flatness of mica or polished silicon wafers can be transferred to metal films, resulting in metal surfaces with topographic features in Angstrom dimensions over large areas. Two decades after its invention, the template-stripping process continues to appeal to scientists from diverse research backgrounds primarily due to its simplicity, cost-effectiveness and ability to yield high quality substrates and structures. This article introduces the basic construction process for template-stripped substrates, and reports on a variety of extensions of the process, including the generation of materials contrasts and the design of tailored topographies. It also highlights the use of such substrates in a variety of research fields in nanoscience and technology ranging from surface force measurement and high definition imaging to the self-assembly of model membranes and plasmonics.
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Affiliation(s)
- Nicolas Vogel
- School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138, USA.
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35
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Campos R, Kataky R. Electron Transport in Supported and Tethered Lipid Bilayers Modified with Bioelectroactive Molecules. J Phys Chem B 2012; 116:3909-17. [DOI: 10.1021/jp209772u] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rui Campos
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Ritu Kataky
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, United Kingdom
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36
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Zagnoni M. Miniaturised technologies for the development of artificial lipid bilayer systems. LAB ON A CHIP 2012; 12:1026-1039. [PMID: 22301684 DOI: 10.1039/c2lc20991h] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Artificially reproducing cellular environments is a key aim of synthetic biology, which has the potential to greatly enhance our understanding of cellular mechanisms. Microfluidic and lab-on-a-chip (LOC) techniques, which enable the controlled handling of sub-microlitre volumes of fluids in an automated and high-throughput manner, can play a major role in achieving this by offering alternative and powerful methodologies in an on-chip format. Such techniques have been successfully employed over the last twenty years to provide innovative solutions for chemical analysis and cell-, molecular- and synthetic- biology. In the context of the latter, the formation of artificial cell membranes (or artificial lipid bilayers) that incorporate membrane proteins within miniaturised LOC architectures offers huge potential for the development of highly sensitive molecular sensors and drug screening applications. The aim of this review is to give a comprehensive and critical overview of the field of microsystems for creating and exploiting artificial lipid bilayers. Advantages and limitations of three of the most popular approaches, namely suspended, supported and droplet-based lipid bilayers, are discussed. Examples are reported that show how artificial cell membrane microsystems, by combining together biological procedures and engineering techniques, can provide novel methodologies for basic biological and biophysical research and for the development of biotechnology tools.
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Affiliation(s)
- Michele Zagnoni
- Centre for Microsystems and Photonics, University of Strathclyde, Glasgow, UK.
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37
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Abstract
AbstractThe synthesis of a new halogenide containing hexyltriethylene glycol chain functionalized with biotin is reported. The general possibility of this linker to use as the building block for biotinylated compounds syntheses is demonstrated. Two biotinylated esters with different properties for useful surface modification and as fluorescence probes for proteins marking were synthesized. The properties of mentioned compounds were investigated by using surface plazmon resonance ellypsometry and fluorescence spectroscopy.
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38
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Kycia AH, Wang J, Merrill AR, Lipkowski J. Atomic force microscopy studies of a floating-bilayer lipid membrane on a Au(111) surface modified with a hydrophilic monolayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:10867-77. [PMID: 21766864 DOI: 10.1021/la2016269] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The surface of a gold electrode was functionalized with a hydrophilic monolayer of 1-thio-β-D-glucose formed by spontaneous self-assembly. The Langmuir-Blodgett/Langmuir-Schaefer (LB/LS) method was then used to assemble a bilayer onto the modified Au(111) surface. The bilayer lipid membrane (BLM) was separated from the Au(111) electrode surface by incorporating the monosialoganglioside GM1 into the inner leaflet of a bilayer composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and cholesterol. To make the inner leaflet, monolayers of GM1/DMPC/cholesterol with mole ratios of 1:6:3, 2:5:3, and 3:4:3 were used. The outer leaflet was composed of a 7:3 mole ratio of DMPC/cholesterol. Because of the amphiphilic properties of GM1, the hydrophobic acyl chains were incorporated into the BLM, whereas the large hydrophilic carbohydrate headgroups were physically adsorbed to the Au(111) electrode surface, creating a "floating" BLM (fBLM). This model contained a water-rich reservoir between the BLM and the gold surface. In addition, because of the bilayer being physically adsorbed onto the support, the fluidity of the BLM was maintained. The compression isotherms were measured at the air/water interface to determine the phase behavior and optimal transfer conditions. The images acquired using atomic force microscopy (AFM) and the force-distance measurements showed that the structure of the fBLM evolved with increasing GM1 content from 10 to 30 mol %, undergoing a transition from a corrugated to a homogeneous phase. This change was associated with a significant increase in bilayer thickness (from ∼5.3 to 7.3 nm). The highest-quality fBLM was produced with 30 mol % GM1.
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Affiliation(s)
- Annia H Kycia
- Department of Chemistry, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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39
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Jung M, Vogel N, Köper I. Nanoscale patterning of solid-supported membranes by integrated diffusion barriers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:7008-7015. [PMID: 21520932 DOI: 10.1021/la200027e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Ultraflat nanostructured substrates have been used as a template to create patterned solid-supported bilayer membranes with polymerizable tethered lipids acting as diffusion barriers. Patterns in the size range of 100 nm were successfully produced and characterized. The diffusion barriers were embedded directly into the phospholipid bilayer and could be used to control the fluidity of the membrane as well as to construct isolated membrane corrals. By using nanosphere lithography to structure the templates it was possible to systematically adjust the lipid diffusion coefficients in a range comparable to those observed in cellular membranes. Single colloids applied as mask in the patterning process yielded substrates for creation of isolated fluid membrane patches corralled by diffusion barriers. Numerous potential applications for this new model system can be envisioned, ranging from the study of cellular interactions or of molecular diffusion in confined geometries to biosensor arrays.
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Affiliation(s)
- Mathieu Jung
- Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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Junghans A, Champagne C, Cayot P, Loupiac C, Köper I. Probing protein-membrane interactions using solid supported membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:2709-2716. [PMID: 21319762 DOI: 10.1021/la103200k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Tethered bilayer lipid membranes have been used as a model system to mimic the interactions between the whey protein β-lactoglobulin and a lipid interface. The approach allowed for a detailed study of the lipid-protein interactions, the results being of possible importance in food and cosmetic applications. For such applications, lipid-protein interactions and the interfacial behavior are vital factors in controlling and manipulating process conditions such as emulsion stabilization and gelification. Lipid composition as well as the structural properties of the protein governed their interactions, which were probed by a combination of surface plasmon spectroscopy, neutron reflectivity, and electrochemical impedance spectroscopy. Comparison of results obtained using native and a partially unfolded protein indicated that the protein preferentially forms loosely packed layers at the lipid interface.
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Affiliation(s)
- Ann Junghans
- Max Planck Institute for Polymer Research, Mainz, Germany
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41
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Abstract
Tethered bilayer lipid membranes can be used as model platforms to host membrane proteins or membrane-active peptides, which can act as transducers in sensing applications. Here we present the synthesis and characterization of a valinomycin derivative, a depsipeptide that has been functionalized to serve as a redox probe in a lipid bilayer. In addition, we discuss the influence of the molecular structure of the lipid bilayer on its ability to host proteins. By using electrical impedance techniques as well as neutron scattering experiments, a clear correlation between the packing density of the lipids forming the membrane and its ability to host membrane proteins could be shown.
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42
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Nielsen CH. Major intrinsic proteins in biomimetic membranes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 679:127-42. [PMID: 20666229 DOI: 10.1007/978-1-4419-6315-4_10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Biological membranes define the structural and functional boundaries in living cells and their organelles. The integrity of the cell depends on its ability to separate inside from outside and yet at the same time allow massive transport of matter in and out the cell. Nature has elegantly met this challenge by developing membranes in the form of lipid bilayers in which specialized transport proteins are incorporated. This raises the question: is it possible to mimic biological membranes and create a membrane based sensor and/or separation device? In the development of a biomimetic sensor/separation technology, a unique class of membrane transport proteins is especially interesting-the major intrinsic proteins (MIPs). Generally, MIPs conduct water molecules and selected solutes in and out of the cell while preventing the passage of other solutes, a property critical for the conservation of the cells internal pH and salt concentration. Also known as water channels or aquaporins they are highly efficient membrane pore proteins some of which are capable of transporting water at very high rates up to 10(9) molecules per second. Some MIPs transport other small, uncharged solutes, such as glycerol and other permeants such as carbon dioxide, nitric oxide, ammonia, hydrogen peroxide and the metalloids antimonite, arsenite, silicic and boric acid depending on the effective restriction mechanism of the protein. The flux properties of MIPs thus lead to the question ifMIPs can be used in separation devices or as sensor devices based on, e.g., the selective permeation of metalloids. In principle a MIP based membrane sensor/separation device requires the supporting biomimetic matrix to be virtually impermeable to anything but water or the solute in question. In practice, however, a biomimetic support matrix will generally have finite permeabilities to both electrolytes and non-electrolytes. The feasibility of a biomimetic MIP device thus depends on the relative transport contribution from both protein and biomimetic support matrix. Also the biomimetic matrix must be encapsulated in order to protect it and make it sufficiently stable in a final application. Here, I specifically discuss the feasibility of developing osmotic biomimetic MIP membranes, but the technical issues are of general concern in the design ofbiomimetic membranes capable of supporting selective transmembrane fluxes.
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Affiliation(s)
- Claus Hélix Nielsen
- Quantrum Protein Center, Department of Physics, Technical University of Denmark, DK-2800 Lyngby.
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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
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Majd S, Yusko EC, Billeh YN, Macrae MX, Yang J, Mayer M. Applications of biological pores in nanomedicine, sensing, and nanoelectronics. Curr Opin Biotechnol 2010; 21:439-76. [PMID: 20561776 PMCID: PMC3121537 DOI: 10.1016/j.copbio.2010.05.002] [Citation(s) in RCA: 237] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 05/03/2010] [Accepted: 05/06/2010] [Indexed: 12/29/2022]
Abstract
Biological protein pores and pore-forming peptides can generate a pathway for the flux of ions and other charged or polar molecules across cellular membranes. In nature, these nanopores have diverse and essential functions that range from maintaining cell homeostasis and participating in cell signaling to activating or killing cells. The combination of the nanoscale dimensions and sophisticated - often regulated - functionality of these biological pores make them particularly attractive for the growing field of nanobiotechnology. Applications range from single-molecule sensing to drug delivery and targeted killing of malignant cells. Potential future applications may include the use of nanopores for single strand DNA sequencing and for generating bio-inspired, and possibly, biocompatible visual detection systems and batteries. This article reviews the current state of applications of pore-forming peptides and proteins in nanomedicine, sensing, and nanoelectronics.
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Affiliation(s)
- Sheereen Majd
- Department of Biomedical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109-2110, USA
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Junghans A, Köper I. Structural analysis of tethered bilayer lipid membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:11035-11040. [PMID: 20504013 DOI: 10.1021/la100342k] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Solid supported membrane systems have been established as biomimetic architectures, which allow for the systematic investigation of various membrane-related processes. Especially tethered bilayer lipid membranes have been a successful concept. They consist of a lipid bilayer that is covalently anchored to a solid substrate through a spacer group. The submembrane part, which is defined by the spacer group, is important especially for the biological activity of incorporated membrane proteins. Anchor lipids with different spacer and anchor groups have been synthesized, and the resulting membrane structures have been investigated by neutron reflectivity. The different molecular architectures had a significant effect on both the amount of water incorporated in the spacer region and the electrical properties of the bilayer. A detailed understanding of the structure-function relationship allows for an optimized design of the molecular architecture with respect to possible applications, for example an optimized protein incorporation.
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Affiliation(s)
- Ann Junghans
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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46
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Abstract
Tethered bilayer lipid membranes have been shown to be an excellent model system for biological membranes. Coupling of a membrane to a solid supports creates a stable system that is accessible for various surface analytical tools. Good electrical sealing properties also enable the use of the membranes in practical sensing applications. The authors have shown that tethered membranes have extended lifetimes up to several months. Air-stability of the bilayer can be achieved by coating the membrane with a hydrogel. The structure of a monolayer and its stability under applied dc potentials have been investigated by neutron scattering.
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47
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Formation of tethered bilayer lipid membranes probed by various surface sensitive techniques. Biointerphases 2010; 4:19-26. [PMID: 20408719 DOI: 10.1116/1.3122019] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Tethered bilayer lipid membranes are promising biomimetic architectures. Their formation has been investigated using four different surface sensitive techniques, including optical, acoustic, and electrical methods. The lipid bilayers are built in a two-step procedure; the proximal layer is formed by self-assembly and is then completed to a bilayer by fusion with small vesicles. The different technical approaches revealed specific aspects of the layer formation processes, namely, first a fast adsorption process followed by a longer rearrangement period. Similar phenomena have been observed for the vesicle fusion process. The results allow for a more controlled assembly protocol for the preparation of highly insulating lipid membranes.
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Canale C, Jacono M, Diaspro A, Dante S. Force spectroscopy as a tool to investigate the properties of supported lipid membranes. Microsc Res Tech 2010; 73:965-72. [DOI: 10.1002/jemt.20834] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lin J, Szymanski J, Searson PC, Hristova K. Effect of a polymer cushion on the electrical properties and stability of surface-supported lipid bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:3544-8. [PMID: 20175577 DOI: 10.1021/la903232b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
A robust biomimetic cell membrane platform is critical for mechanistic studies of membrane protein channels. While polymer cushions are believed to facilitate the incorporation of membrane proteins in such a platform, a systematic characterization and optimization of such cushions is rarely performed. Here, we examine the influence of a polymer cushion on the electrical properties of supported 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) bilayers produced via a Langmuir-Blodgett deposition/vesicle fusion assembly process on single-crystal silicon. We show that the resistance of DPhPC bilayers is maximized at the calculated crossover concentration of the polymer (5.9 mol % PEG-lipids). Additionally, these bilayers are sufficiently stable to allow impedance analyses to be performed for nearly 3 weeks. These studies reveal the optimal PEG concentration that yields electrically robust bilayers and demonstrate the utility of the platform for future studies of membrane protein channels and membrane active peptides.
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Affiliation(s)
- Janice Lin
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
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50
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Vogel N, Jung M, Bocchio NL, Retsch M, Kreiter M, Köper I. Reusable localized surface plasmon sensors based on ultrastable nanostructures. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2010; 6:104-9. [PMID: 19899088 DOI: 10.1002/smll.200900497] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Nanoparticle arrays created by nanosphere lithography are widely used in sensing applications since their localized surface plasmon resonances are extremely sensitive to changes in the local dielectric environment. A major drawback for any biologically oriented sensing application of conventionally produced particle arrays is the lack of stability of the nanoparticles in aqueous media and buffer solutions. Here, a robust and reusable nanoscale sensing platform based on localized surface plasmon resonances of gold nanoparticles embedded in a silicon dioxide matrix is presented. The architecture exhibits extremely high stability in aqueous environments and can be regenerated several times by simple mechanical cleaning of the surface. The platforms surface is ultraflat by design, thus making it an ideal substrate for any bio-oriented sensing application.
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Affiliation(s)
- Nicolas Vogel
- Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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