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Kim JS, Kwon SY, Lee JY, Kim SD, Kim DY, Kim H, Jang N, Wang J, Han M, Kong SH. High-throughput multi-gate microfluidic resistive pulse sensing for biological nanoparticle detection. LAB ON A CHIP 2023; 23:1945-1953. [PMID: 36897079 DOI: 10.1039/d2lc01064j] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
A microfluidic resistive pulse sensing technique offers a simple method for detecting and analysing microparticles in various fields, yet it has challenges such as the noise during detection and low throughput as the signal obtained from a small single sensing aperture and particle position is nonuniform. This study presents a microfluidic chip with multiple detection gates in the main channel to enhance the throughput while maintaining a simple operational system. A hydrodynamic sheathless particle focusing on a detection gate by modulation of the channel structure and measurement circuit with a reference gate to minimize the noise during detection is used for detecting resistive pulses. The proposed microfluidic chip can analyse the physical properties of 200 nm polystyrene particles and exosomes from MDA-MB-231 with high sensitivity with an error of <10% and high-throughput screening of more than 200 000 exosomes per seconds. The proposed microfluidic chip can analyse the physical properties with high sensitivity, so that it can be potentially used for exosome detection in biological and in vitro clinical applications.
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Affiliation(s)
- June Soo Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Soon Yeol Kwon
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Jae Yong Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Seung Deok Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Da Ye Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Hyunjun Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Noah Jang
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Jiajie Wang
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Maeum Han
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
| | - Seong Ho Kong
- School of Electronic and Electrical Engineering, Kyungpook National University, 41566, Daegu, Republic of Korea.
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2
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Li Z, Misra RP, Li Y, Yao YC, Zhao S, Zhang Y, Chen Y, Blankschtein D, Noy A. Breakdown of the Nernst-Einstein relation in carbon nanotube porins. NATURE NANOTECHNOLOGY 2023; 18:177-183. [PMID: 36585518 DOI: 10.1038/s41565-022-01276-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
For over 100 years, the Nernst-Einstein relation has linked a charged particle's electrophoretic mobility and diffusion coefficient. Here we report experimental measurements of diffusion and electromigration of K+ ions in narrow 0.8-nm-diameter single-walled carbon nanotube porins (CNTPs) and demonstrate that the Nernst-Einstein relation in these channels breaks down by more than three orders of magnitude. Molecular dynamics simulations using polarizable force fields show that K+ ion diffusion in CNTPs in the presence of a single-file water chain is three orders of magnitude slower than bulk diffusion. Intriguingly, the simulations also reveal a disintegration of the water chain upon application of electric fields, resulting in the formation of distinct K+-water clusters, which then traverse the CNTP at high velocity. Finally, we show that although individual ion-water clusters still obey the Nernst-Einstein relation, the overall relation breaks down because of two distinct mechanisms for ion diffusion and electromigration.
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Affiliation(s)
- Zhongwu Li
- Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, China
- School of Mechatronic Engineering, China University of Mining and Technology, Xuzhou, China
| | - Rahul Prasanna Misra
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yuhao Li
- Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Yun-Chiao Yao
- Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
- School of Natural Sciences, University of California Merced, Merced, CA, USA
| | - Sidi Zhao
- Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
- School of Engineering, University of California Merced, Merced, CA, USA
| | - Yuliang Zhang
- Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Yunfei Chen
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, China
| | - Daniel Blankschtein
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Aleksandr Noy
- Materials Science Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.
- School of Natural Sciences, University of California Merced, Merced, CA, USA.
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3
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Parperis C, Wallace MI. Single-molecule imaging of pore-forming toxin dynamics in droplet interface bilayers. Methods Enzymol 2021; 649:431-459. [PMID: 33712195 DOI: 10.1016/bs.mie.2021.01.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Single-channel recording from pore-forming toxins (PFTs) provides a clear and direct molecular readout of toxin action. However to complete any mechanistic understanding of PFT behavior, this functional kinetic readout must be linked to the underlying changes in toxin structure, binding, conformation, or stoichiometry. Here we review how single-molecule imaging methods might be used to further our understanding of PFTs, and provide detailed practical guidance on the use of droplet interface bilayers as a method capable of examining both single-molecule fluorescence and single-channel electrical signals from PFTs.
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Affiliation(s)
- Christopher Parperis
- Department of Chemistry, Britannia House, King's College London, London, United Kingdom
| | - Mark I Wallace
- Department of Chemistry, Britannia House, King's College London, London, United Kingdom.
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4
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Sun Y, Zang X, Sun Y, Wang L, Gao Z. Lipid membranes supported by planar porous substrates. Chem Phys Lipids 2020; 228:104893. [PMID: 32097619 DOI: 10.1016/j.chemphyslip.2020.104893] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/10/2020] [Indexed: 12/18/2022]
Abstract
Biological membranes play key roles in cell life, but their intrinsic complexity motivated the study and development of artificial lipid membranes with the primary aim to reconstitute and understand the natural functions in vitro. Porous-supported lipid membrane (pSLM) has emerged as a flexible platform for studying the surface chemistry of the cell due to their high stability and fluidity, and their ability to study the transmembrane process of the molecules. In this review, the pSLM, for the first time, to our knowledge, was divided into three types according to the way of the porous materials support the lipid membrane, containing the lipid membrane on the pores of the porous materials, the lipid membrane on both sides of the porous materials, the lipid membrane in the pores of the porous materials. All of these pSLMs were systematically elaborated from several aspects, including the substrates, formation, and characterization. Meanwhile, the advantages and disadvantages of each model membranes were summarized. Finally, suggestions for selecting appropriate pSLM and future directions in this area are discussed.
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Affiliation(s)
- Yanping Sun
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, 050018, China; State Key Laboratory Breeding Base - Hebei Province Key Laboratory of Molecular Chemistry for Drugs, Hebei University of Science and Technology, Shijiazhuang, 050018, China; Hebei Research Center of Pharmaceutical and Chemical Engineering, Hebei University of Science and Technology, Shijiazhuang, 050018, China
| | - Xianghuan Zang
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, 050018, China
| | - Yongjun Sun
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, 050018, China; Hebei Research Center of Pharmaceutical and Chemical Engineering, Hebei University of Science and Technology, Shijiazhuang, 050018, China
| | - Long Wang
- State Key Laboratory Breeding Base - Hebei Province Key Laboratory of Molecular Chemistry for Drugs, Hebei University of Science and Technology, Shijiazhuang, 050018, China; Department of Family and Consumer Sciences, California State University, Long Beach, CA, 90840, USA.
| | - Zibin Gao
- Department of Pharmacy, Hebei University of Science and Technology, Shijiazhuang, 050018, China; State Key Laboratory Breeding Base - Hebei Province Key Laboratory of Molecular Chemistry for Drugs, Hebei University of Science and Technology, Shijiazhuang, 050018, China; Hebei Research Center of Pharmaceutical and Chemical Engineering, Hebei University of Science and Technology, Shijiazhuang, 050018, China.
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5
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The Role of Lipid Interactions in Simulations of the α-Hemolysin Ion-Channel-Forming Toxin. Biophys J 2018; 115:1720-1730. [PMID: 30287110 DOI: 10.1016/j.bpj.2018.09.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 09/04/2018] [Accepted: 09/07/2018] [Indexed: 01/25/2023] Open
Abstract
Molecular dynamics simulations were performed to describe the function of the ion-channel-forming toxin α-hemolysin (αHL) in lipid membranes that were composed of either 1,2-diphytanoyl-sn-glycero-3-phospho-choline or 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-choline. The simulations highlight the importance of lipid type in maintaining αHL structure and function, enabling direct comparison to experiments for biosensing applications. We determined that although the two lipids studied are similar in structure, 1,2-diphytanoyl-sn-glycero-3-phospho-choline membranes better match the hydrophobic thickness of αHL compared to 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-choline membranes. This hydrophobic match is essential to maintaining proper alignment of β-sheet loops at the trans entrance of αHL, which, when disrupted, creates an additional constriction to ion flow that decreases the channel current below experimental values and creates greater variability in channel conductance. Agreement with experiments was further improved with sufficient lipid membrane equilibration and allowed the discrimination of subtle αHL conduction states with lipid type. Finally, we explore the effects of truncating the extramembrane cap of αHL and its role in maintaining proper alignment of αHL in the membrane and channel conductance. Our results demonstrate the essential role of lipid type and lipid-protein interactions in simulations of αHL and will considerably improve the interpretation of experimental data.
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6
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Schulze Greiving VC, de Boer HL, Bomer JG, van den Berg A, Le Gac S. Integrated microfluidic biosensing platform for simultaneous confocal microscopy and electrophysiological measurements on bilayer lipid membranes and ion channels. Electrophoresis 2017; 39:496-503. [PMID: 29193178 DOI: 10.1002/elps.201700346] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/04/2017] [Accepted: 11/05/2017] [Indexed: 01/19/2023]
Abstract
Combining high-resolution imaging and electrophysiological recordings is key for various types of experimentation on lipid bilayers and ion channels. Here, we propose an integrated biosensing platform consisting of a microfluidic cartridge and a dedicated chip-holder to conduct such dual measurements on suspended lipid bilayers, in a user-friendly manner. To illustrate the potential of the integrated platform, we characterize lipid bilayers in terms of thickness and fluidity while simultaneously monitoring single ion channel currents. For that purpose, POPC lipid bilayers are supplemented with a fluorescently-tagged phospholipid (NBD-PE, 1% mol) for Fluorescence Recovery After Photobleaching (FRAP) measurements and a model ion channel (gramicidin, 1 nM). These combined measurements reveal that NBD-PE has no effect on the lipid bilayer thickness while gramicidin induces thinning of the membrane. Furthermore, the presence of gramicidin does not alter the lipid bilayer fluidity. Surprisingly, in lipid bilayers supplemented with both probes, a reduction in gramicidin open probability and lifetime is observed compared to lipid bilayers with gramicidin only, suggesting an influence of NBD-PE on the gramicidin ion function. Altogether, our proposed microfluidic biosensing platform in combination with the herein presented multi-parametric measurement scheme paves the way to explore the interdependent relationship between lipid bilayer properties and ion channel function.
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Affiliation(s)
- Verena C Schulze Greiving
- BIOS, Lab on a chip Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Hans L de Boer
- BIOS, Lab on a chip Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Johan G Bomer
- BIOS, Lab on a chip Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Albert van den Berg
- BIOS, Lab on a chip Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Séverine Le Gac
- BIOS, Lab on a chip Group, MESA+ Institute for Nanotechnology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
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7
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Song Y, Zhang J, Li D. Microfluidic and Nanofluidic Resistive Pulse Sensing: A Review. MICROMACHINES 2017; 8:E204. [PMID: 30400393 PMCID: PMC6190343 DOI: 10.3390/mi8070204] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 06/11/2017] [Accepted: 06/21/2017] [Indexed: 12/31/2022]
Abstract
The resistive pulse sensing (RPS) method based on the Coulter principle is a powerful method for particle counting and sizing in electrolyte solutions. With the advancement of micro- and nano-fabrication technologies, microfluidic and nanofluidic resistive pulse sensing technologies and devices have been developed. Due to the unique advantages of microfluidics and nanofluidics, RPS sensors are enabled with more functions with greatly improved sensitivity and throughput and thus have wide applications in fields of biomedical research, clinical diagnosis, and so on. Firstly, this paper reviews some basic theories of particle sizing and counting. Emphasis is then given to the latest development of microfuidic and nanofluidic RPS technologies within the last 6 years, ranging from some new phenomena, methods of improving the sensitivity and throughput, and their applications, to some popular nanopore or nanochannel fabrication techniques. The future research directions and challenges on microfluidic and nanofluidic RPS are also outlined.
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Affiliation(s)
- Yongxin Song
- Department of Marine Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Junyan Zhang
- Department of Marine Engineering, Dalian Maritime University, Dalian 116026, China.
| | - Dongqing Li
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
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8
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Imaging potassium-flux through individual electropores in droplet interface bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015. [PMID: 26210300 DOI: 10.1016/j.bbamem.2015.07.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Using total internal reflection fluorescence microscopy of droplet interface bilayers containing the potassium-sensitive fluorophore APG-4, we imaged the ionic flux through individual electropores. We are able to monitor up to 30 individual pores in parallel and show voltage dependent responses in fluorescence that corresponds to the measured ionic current. These experiments help quantify the scope and current limitations of optical single channel recordings of potassium flux. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale.
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9
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Janshoff A, Steinem C. Mechanics of lipid bilayers: What do we learn from pore-spanning membranes? BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2977-83. [PMID: 26025679 DOI: 10.1016/j.bbamcr.2015.05.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 05/21/2015] [Accepted: 05/22/2015] [Indexed: 11/18/2022]
Abstract
The mechanical properties of biological membranes have become increasingly important not only from a biophysical viewpoint but also as they play a substantial role in the information transfer in cells and tissues. This minireview summarizes some of our recent understanding of the mechanical properties of artificial model membranes with particular emphasis on membranes suspending an array of pores, so called pore-spanning membranes. A theoretical description of the mechanical properties of these membranes might pave the way to biophysically describe and understand the complex behavior of native biological membranes. This article is part of a Special Issue entitled: Mechanobiology.
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Affiliation(s)
- Andreas Janshoff
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstr. 2, 37077 Göttingen, Germany; Institute of Physical Chemistry, University of Göttingen, Tammannstr. 6, 37077 Göttingen, Germany
| | - Claudia Steinem
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstr. 2, 37077 Göttingen, Germany; Institute of Physical Chemistry, University of Göttingen, Tammannstr. 6, 37077 Göttingen, Germany.
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10
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Tsugane M, Uejima E, Suzuki H. Microchamber device for detection of transporter activity of adherent cells. Front Bioeng Biotechnol 2015; 3:32. [PMID: 25853126 PMCID: PMC4364289 DOI: 10.3389/fbioe.2015.00032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 03/02/2015] [Indexed: 12/20/2022] Open
Abstract
We present a method to detect the transporter activity of intact adherent cells using a microchamber device. When adherent cells are seeded onto the poly-di-methyl siloxane substrate having microchambers with openings smaller than the size of a cell, the cells form a confluent layer that covers the microchambers, creating minute, confined spaces. As substances exported across the cell membrane accumulate, transporter activity can be detected by observing the fluorescence intensity increase in the microchamber. We tested the microchamber device with HeLa cells over-expressing MDR1, an ATP-binding cassette transporter, and succeeded in detecting the transport of fluorescence-conjugated paclitaxel, the anti-cancer drug, at the single-cell level.
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Affiliation(s)
- Mamiko Tsugane
- Department of Precision Mechanics, Faculty of Science and Engineering, Chuo University , Tokyo , Japan ; Department of Clinical Pharmacy Research and Education, Graduate School of Pharmaceutical Sciences, Osaka University , Osaka , Japan
| | - Etsuko Uejima
- Department of Clinical Pharmacy Research and Education, Graduate School of Pharmaceutical Sciences, Osaka University , Osaka , Japan
| | - Hiroaki Suzuki
- Department of Precision Mechanics, Faculty of Science and Engineering, Chuo University , Tokyo , Japan
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11
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Teng W, Ban C, Hahn JH. Formation of lipid bilayer membrane in a poly(dimethylsiloxane) microchip integrated with a stacked polycarbonate membrane support and an on-site nanoinjector. BIOMICROFLUIDICS 2015; 9:024120. [PMID: 26015832 PMCID: PMC4409621 DOI: 10.1063/1.4919066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 04/14/2015] [Indexed: 06/04/2023]
Abstract
This paper describes a new and facile approach for the formation of pore-spanning bilayer lipid membranes (BLMs) within a poly(dimethylsiloxane) (PDMS) microfluidic device. Commercially, readily available polycarbonate (PC) membranes are employed for the support of BLMs. PC sheets with 5 μm, 2 μm, and 0.4 μm pore diameters, respectively, are thermally bonded into a multilayer-stack, reducing the pore density of 0.4 μm-pore PC by a factor of 200. The BLMs on this support are considerably stable (a mean lifetime: 17 h). This multilayer-stack PC (MSPC) membrane is integrated into the PDMS chip by an epoxy bonding method developed to secure durable bonding under the use of organic solvents. The microchip has a special channel for guiding a micropipette in the proximity of the MSPC support. With this on-site injection technique, tens to hundreds of nanoliters of solutions can be directly dispensed to the support. Incorporating gramicidin ion channels into BLMs on the MSPC support has confirmed the formation of single BLMs, which is based on the observation from current signals of 20 pS conductance that is typical to single channel opening. Based on the bilayer capacitance (1.4 pF), about 15% of through pores across the MSPC membrane are estimated to be covered with BLMs.
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Affiliation(s)
- Wei Teng
- Department of Chemistry, BioNanotechnology Center, Pohang University of Science and Technology , 77 Cheongam-Ro, Nam-Gu, 790-784 Pohang, South Korea
| | - Changill Ban
- Department of Chemistry, BioNanotechnology Center, Pohang University of Science and Technology , 77 Cheongam-Ro, Nam-Gu, 790-784 Pohang, South Korea
| | - Jong Hoon Hahn
- Department of Chemistry, BioNanotechnology Center, Pohang University of Science and Technology , 77 Cheongam-Ro, Nam-Gu, 790-784 Pohang, South Korea
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12
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Weatherill EE, Wallace MI. Combining Single-Molecule Imaging and Single-Channel Electrophysiology. J Mol Biol 2015; 427:146-57. [DOI: 10.1016/j.jmb.2014.07.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/07/2014] [Accepted: 07/07/2014] [Indexed: 12/29/2022]
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13
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Tonnesen A, Christensen SM, Tkach V, Stamou D. Geometrical membrane curvature as an allosteric regulator of membrane protein structure and function. Biophys J 2014; 106:201-9. [PMID: 24411252 DOI: 10.1016/j.bpj.2013.11.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 11/07/2013] [Accepted: 11/12/2013] [Indexed: 10/25/2022] Open
Abstract
Transmembrane proteins are embedded in cellular membranes of varied lipid composition and geometrical curvature. Here, we studied for the first time the allosteric effect of geometrical membrane curvature on transmembrane protein structure and function. We used single-channel optical analysis of the prototypic transmembrane β-barrel α-hemolysin (α-HL) reconstituted on immobilized single small unilamellar liposomes of different diameter and therefore curvature. Our data demonstrate that physiologically abundant geometrical membrane curvatures can enforce a dramatic allosteric regulation (1000-fold inhibition) of α-HL permeability. High membrane curvatures (1/diameter ~1/40 nm(-1)) compressed the effective pore diameter of α-HL from 14.2 ± 0.8 Å to 11.4 ± 0.6 Å. This reduction in effective pore area (~40%) when combined with the area compressibility of α-HL revealed an effective membrane tension of ~50 mN/m and a curvature-imposed protein deformation energy of ~7 kBT. Such substantial energies have been shown to conformationally activate, or unfold, β-barrel and α-helical transmembrane proteins, suggesting that membrane curvature could likely regulate allosterically the structure and function of transmembrane proteins in general.
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Affiliation(s)
- Asger Tonnesen
- Bionanotechnology and Nanomedicine Laboratory, Department of Chemistry, University of Copenhagen, Copenhagen, Denmark; Nano-Science Center, University of Copenhagen, Copenhagen, Denmark; Lundbeck Foundation Center for Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
| | - Sune M Christensen
- Bionanotechnology and Nanomedicine Laboratory, Department of Chemistry, University of Copenhagen, Copenhagen, Denmark; Nano-Science Center, University of Copenhagen, Copenhagen, Denmark; Lundbeck Foundation Center for Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
| | - Vadym Tkach
- Bionanotechnology and Nanomedicine Laboratory, Department of Chemistry, University of Copenhagen, Copenhagen, Denmark; Nano-Science Center, University of Copenhagen, Copenhagen, Denmark; Lundbeck Foundation Center for Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark
| | - Dimitrios Stamou
- Bionanotechnology and Nanomedicine Laboratory, Department of Chemistry, University of Copenhagen, Copenhagen, Denmark; Nano-Science Center, University of Copenhagen, Copenhagen, Denmark; Lundbeck Foundation Center for Biomembranes in Nanomedicine, University of Copenhagen, Copenhagen, Denmark.
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14
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Arriaga LR, Datta SS, Kim SH, Amstad E, Kodger TE, Monroy F, Weitz DA. Ultrathin shell double emulsion templated giant unilamellar lipid vesicles with controlled microdomain formation. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:950-6. [PMID: 24150883 DOI: 10.1002/smll.201301904] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 08/14/2013] [Indexed: 05/04/2023]
Abstract
A microfluidic approach is reported for the high-throughput, continuous production of giant unilamellar vesicles (GUVs) using water-in-oil-in-water double emulsion drops as templates. Importantly, these emulsion drops have ultrathin shells; this minimizes the amount of residual solvent that remains trapped within the GUV membrane, overcoming a major limitation of typical microfluidic approaches for GUV fabrication. This approach enables the formation of microdomains, characterized by different lipid compositions and structures within the GUV membranes. This work therefore demonstrates a straightforward and versatile approach to GUV fabrication with precise control over the GUV size, lipid composition and the formation of microdomains within the GUV membrane.
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Affiliation(s)
- Laura R Arriaga
- School of Engineering and Applied Sciences and Department of Physics, Harvard University, Cambridge, MA, 02138, USA
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15
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Xu J, Vanderlick TK, Beales PA. Lytic and non-lytic permeabilization of cardiolipin-containing lipid bilayers induced by cytochrome C. PLoS One 2013; 8:e69492. [PMID: 23894494 PMCID: PMC3718682 DOI: 10.1371/journal.pone.0069492] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 06/10/2013] [Indexed: 12/11/2022] Open
Abstract
The release of cytochrome c (cyt c) from mitochondria is an important early step during cellular apoptosis, however the precise mechanism by which the outer mitochondrial membrane becomes permeable to these proteins is as yet unclear. Inspired by our previous observation of cyt c crossing the membrane barrier of giant unilamellar vesicle model systems, we investigate the interaction of cyt c with cardiolipin (CL)-containing membranes using the innovative droplet bilayer system that permits electrochemical measurements with simultaneous microscopy observation. We find that cyt c can permeabilize CL-containing membranes by induction of lipid pores in a dose-dependent manner, with membrane lysis eventually observed at relatively high (µM) cyt c concentrations due to widespread pore formation in the membrane destabilizing its bilayer structure. Surprisingly, as cyt c concentration is further increased, we find a regime with exceptionally high permeability where a stable membrane barrier is still maintained between droplet compartments. This unusual non-lytic state has a long lifetime (>20 h) and can be reversibly formed by mechanically separating the droplets before reforming the contact area between them. The transitions between behavioural regimes are electrostatically driven, demonstrated by their suppression with increasing ionic concentrations and their dependence on CL composition. While membrane permeability could also be induced by cationic PAMAM dendrimers, the non-lytic, highly permeable membrane state could not be reproduced using these synthetic polymers, indicating that details in the structure of cyt c beyond simply possessing a cationic net charge are important for the emergence of this unconventional membrane state. These unexpected findings may hold significance for the mechanism by which cyt c escapes into the cytosol of cells during apoptosis.
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Affiliation(s)
- Jian Xu
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut, United States of America
| | - T. Kyle Vanderlick
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut, United States of America
| | - Paul A. Beales
- Centre for Molecular Nanoscience, School of Chemistry, University of Leeds, Leeds, United Kingdom
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Stimberg VC, Bomer JG, van Uitert I, van den Berg A, Le Gac S. High yield, reproducible and quasi-automated bilayer formation in a microfluidic format. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:1076-1085. [PMID: 23139010 DOI: 10.1002/smll.201201821] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 08/27/2012] [Indexed: 05/28/2023]
Abstract
A microfluidic platform is reported for various experimentation schemes on cell membrane models and membrane proteins using a combination of electrical and optical measurements, including confocal microscopy. Bilayer lipid membranes (BLMs) are prepared in the device upon spontaneous and instantaneous thinning of the lipid solution in a 100-μm dry-etched aperture in a 12.5-μm thick Teflon foil. Using this quasi-automated approach, a remarkable 100% membrane formation yield is reached (including reflushing in 4% of the cases), and BLMs are stable for up to 36 h. Furthermore, the potential of this platform is demonstrated for (i) the in-depth characterization of BLMs comprising both synthetic and natural lipids (1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) and L-α-phosphatidylcholine (L-α-PC)/cholesterol, respectively) in terms of seal resistance, capacitance, surface area, specific capacitance, and membrane hydrophobic thickness; (ii) confocal microscopy imaging of phase separation in sphingomyelin/L-α-PC/cholesterol ternary membranes; (iii) electrical measurements of individual nanopores (α-hemolysin, gramicidin); and (iv) indirect assessment of the alteration of membrane properties upon exposure to chemical stimuli using the natural nanopore gramicidin as a sensor.
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Affiliation(s)
- Verena C Stimberg
- BIOS-Lab on a Chip Group, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands
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17
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Frese D, Steltenkamp S, Schmitz S, Steinem C. In situ generation of electrochemical gradients across pore-spanning membranes. RSC Adv 2013. [DOI: 10.1039/c3ra42723d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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18
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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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19
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Schmidt F, Levin J, Kamp F, Kretzschmar H, Giese A, Bötzel K. Single-channel electrophysiology reveals a distinct and uniform pore complex formed by α-synuclein oligomers in lipid membranes. PLoS One 2012; 7:e42545. [PMID: 22880029 PMCID: PMC3411845 DOI: 10.1371/journal.pone.0042545] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 07/10/2012] [Indexed: 02/06/2023] Open
Abstract
Synucleinopathies such as Parkinson's disease, multiple system atrophy and dementia with Lewy bodies are characterized by deposition of aggregated α-synuclein. Recent findings indicate that pathological oligomers rather than fibrillar aggregates may represent the main toxic protein species. It has been shown that α-synuclein oligomers can increase the conductance of lipid bilayers and, in cell-culture, lead to calcium dyshomeostasis and cell death. In this study, employing a setup for single-channel electrophysiology, we found that addition of iron-induced α-synuclein oligomers resulted in quantized and stepwise increases in bilayer conductance indicating insertion of distinct transmembrane pores. These pores switched between open and closed states depending on clamped voltage revealing a single-pore conductance comparable to that of bacterial porins. Pore conductance was dependent on transmembrane potential and the available cation. The pores stably inserted into the bilayer and could not be removed by buffer exchange. Pore formation could be inhibited by co-incubation with the aggregation inhibitor baicalein. Our findings indicate that iron-induced α-synuclein oligomers can form a uniform and distinct pore species with characteristic electrophysiological properties. Pore formation could be a critical event in the pathogenesis of synucleinopathies and provide a novel structural target for disease-modifying therapy.
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Affiliation(s)
- Felix Schmidt
- Neurologische Klinik, Klinikum der Universität München, Ludwig-Maximilians-Universität München, München, Germany
- Zentrum für Neuropathologie und Prionforschung, Ludwig-Maximilians-Universität München, München, Germany
| | - Johannes Levin
- Neurologische Klinik, Klinikum der Universität München, Ludwig-Maximilians-Universität München, München, Germany
| | - Frits Kamp
- Neurologische Klinik, Klinikum der Universität München, Ludwig-Maximilians-Universität München, München, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen und Adolf-Butenandt-Institut, Ludwig-Maximilians-Universität München, München, Germany
| | - Hans Kretzschmar
- Zentrum für Neuropathologie und Prionforschung, Ludwig-Maximilians-Universität München, München, Germany
| | - Armin Giese
- Zentrum für Neuropathologie und Prionforschung, Ludwig-Maximilians-Universität München, München, Germany
- * E-mail:
| | - Kai Bötzel
- Neurologische Klinik, Klinikum der Universität München, Ludwig-Maximilians-Universität München, München, Germany
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20
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Castell OK, Berridge J, Wallace MI. Quantification of Membrane Protein Inhibition by Optical Ion Flux in a Droplet Interface Bilayer Array. Angew Chem Int Ed Engl 2012; 51:3134-8. [DOI: 10.1002/anie.201107343] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 01/24/2012] [Indexed: 01/01/2023]
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21
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Castell OK, Berridge J, Wallace MI. Quantification of Membrane Protein Inhibition by Optical Ion Flux in a Droplet Interface Bilayer Array. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201107343] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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22
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Harsman A, Bartsch P, Hemmis B, Krüger V, Wagner R. Exploring protein import pores of cellular organelles at the single molecule level using the planar lipid bilayer technique. Eur J Cell Biol 2012; 90:721-30. [PMID: 21684628 DOI: 10.1016/j.ejcb.2011.04.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Proteins of living cells carry out their specialized functions within various subcellular membranes or aqueous spaces. Approximately half of all the proteins of a typical cell are transported into or across membranes. Targeting and transport to their correct subcellular destinations are essential steps in protein biosynthesis. In eukaryotic cells secretory proteins are transported into the endoplasmic reticulum before they are transported in vesicles to the plasma membrane. Virtually all proteins of the endosymbiotic organelles, chloroplasts and mitochondria, are synthesized on cytosolic ribosomes and posttranslationally imported. Genetic and biochemical techniques led to rather detailed knowledge on the subunit composition of the various protein transport complexes which carry out the membrane transport of the preproteins. Conclusive concepts on targeting and cytosolic transport of polypeptides emerged, while still few details on the molecular nature and mechanisms of the channel moieties of protein translocation complexes have been achieved. In this paper we will describe the history of how the individual subunits forming the channel pores of the chloroplast, mitochondrial and endoplasmic reticulum protein import machineries were identified and characterized by single channel electrophysiological techniques in planar bilayers. We will also highlight recent developments in the exploration of the molecular properties of protein translocating channels and the regulation of the diverse protein translocation systems using the planar bilayer technique.
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Affiliation(s)
- Anke Harsman
- University of Osnabrück, Faculty of Biology and Chemistry, Department of Biophysics, Barbarastr. 13, 49076 Osnabrück, Germany
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Sumitomo K, McAllister A, Tamba Y, Kashimura Y, Tanaka A, Shinozaki Y, Torimitsu K. Ca2+ ion transport through channels formed by α-hemolysin analyzed using a microwell array on a Si substrate. Biosens Bioelectron 2011; 31:445-50. [PMID: 22152991 DOI: 10.1016/j.bios.2011.11.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 11/06/2011] [Indexed: 10/15/2022]
Abstract
For the functional analysis of ion channel activity, an artificial lipid bilayer suspended over microwells was formed that ruptured giant unilamellar vesicles on a Si substrate. Ca(2+) ion indicators (fluo-4) were confined in the microwells by sealing the microwells with a lipid bilayer. An overhang formed at the microwells prevented the lipid membrane from falling into them and allowed the stable confinement of the fluorescent probes. The transport of Ca(2+) ions through the channels formed by α-hemolysin inserted in a lipid membrane was analyzed by employing the fluorescence intensity change of fluo-4 in the microwells. The microwell volume was very small (1-100 fl), so a highly sensitive monitor could be realized. The detection limit is several tens of ions/s/μm(2), and this is much smaller than the ion current in a standard electrophysiological measurement. Smaller microwells will make it possible to mimic a local ion concentration change in the cells, although the signal to noise ratio must be further improved for the functional analysis of a single channel. We demonstrated that a microwell array with confined fluorescent probes sealed by a lipid bilayer could constitute a basic component of a highly sensitive biosensor array that works with functional membrane proteins. This array will allow us to realize high throughput and parallel testing devices.
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Affiliation(s)
- Koji Sumitomo
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198, Japan.
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24
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Ota S, Suzuki H, Takeuchi S. Microfluidic lipid membrane formation on microchamber arrays. LAB ON A CHIP 2011; 11:2485-2487. [PMID: 21701764 DOI: 10.1039/c1lc20334g] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present a simple method to form free-standing lipid membranes on arrayed microchambers (>100). The formed membranes are perpendicular to an imaging plane with control of solute concentration on each side of the membranes. This platform let us quantitatively detect membrane transport of non-charged fluorescent molecules, induced by membrane proteins.
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Affiliation(s)
- Sadao Ota
- Institute of Industrial Sciences, The University of Tokyo, 4-6-1 Komaba, Tokyo 153-8505, Japan
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25
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Roerdink Lander M, Ibragimova S, Rein C, Vogel J, Stibius K, Geschke O, Perry M, Hélix-Nielsen C. Biomimetic membrane arrays on cast hydrogel supports. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:7002-7007. [PMID: 21526805 DOI: 10.1021/la1050699] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Lipid bilayers are intrinsically fragile and require mechanical support in technical applications based on biomimetic membranes. Tethering the lipid bilayer membranes to solid substrates, either directly through covalent or ionic substrate-lipid links or indirectly on substrate-supported cushions, provides mechanical support but at the cost of small molecule transport through the membrane-support sandwich. To stabilize biomimetic membranes while allowing transport through a membrane-support sandwich, we have investigated the feasibility of using an ethylene tetrafluoroethylene (ETFE)/hydrogel sandwich as the support. The sandwich is realized as a perforated surface-treated ETFE film onto which a hydrogel composite support structure is cast. We report a simple method to prepare arrays of lipid bilayer membranes with low intrinsic electrical conductance on the highly permeable, self-supporting ETFE/hydrogel sandwiches. We demonstrate how the ETFE/hydrogel sandwich support promotes rapid self-thinning of lipid bilayers suitable for hosting membrane-spanning proteins.
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26
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Kawano R, Osaki T, Sasaki H, Takeuchi S. A polymer-based nanopore-integrated microfluidic device for generating stable bilayer lipid membranes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2010; 6:2100-2104. [PMID: 20839243 DOI: 10.1002/smll.201000997] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Affiliation(s)
- Ryuji Kawano
- Bio Microsystems Project, Kanagawa Academy of Science and Technology, Kawasaki City 213-0012, Japan
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27
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Balabdaoui F, Bissantz K, Bissantz N, Holzmann H. Demonstrating Single and Multiple Currents Through the E. coli-SecYEG-Pore: Testing for the Number of Modes of Noisy Observations. J Am Stat Assoc 2010. [DOI: 10.1198/jasa.2009.ap08070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Fadoua Balabdaoui
- Fadoua Balabdaoui is Assistant Professor, CEREMADE, Université Paris-Dauphine, 75775 Paris cedex 16, France . Kathrin Bissantz is Teaching Assistant, CenTech–Center for Nanotechnology, Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany . Nicolai Bissantz is Senior Lecturer, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany . Hajo Holzmann is Professor, Fachbereich Mathematik und Informatik, Phillips-Universität Marburg, Hans-Meerweinstraße, 35032 Marburg, Germany
| | - Kathrin Bissantz
- Fadoua Balabdaoui is Assistant Professor, CEREMADE, Université Paris-Dauphine, 75775 Paris cedex 16, France . Kathrin Bissantz is Teaching Assistant, CenTech–Center for Nanotechnology, Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany . Nicolai Bissantz is Senior Lecturer, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany . Hajo Holzmann is Professor, Fachbereich Mathematik und Informatik, Phillips-Universität Marburg, Hans-Meerweinstraße, 35032 Marburg, Germany
| | - Nicolai Bissantz
- Fadoua Balabdaoui is Assistant Professor, CEREMADE, Université Paris-Dauphine, 75775 Paris cedex 16, France . Kathrin Bissantz is Teaching Assistant, CenTech–Center for Nanotechnology, Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany . Nicolai Bissantz is Senior Lecturer, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany . Hajo Holzmann is Professor, Fachbereich Mathematik und Informatik, Phillips-Universität Marburg, Hans-Meerweinstraße, 35032 Marburg, Germany
| | - Hajo Holzmann
- Fadoua Balabdaoui is Assistant Professor, CEREMADE, Université Paris-Dauphine, 75775 Paris cedex 16, France . Kathrin Bissantz is Teaching Assistant, CenTech–Center for Nanotechnology, Universität Münster, Heisenbergstr. 11, 48149 Münster, Germany . Nicolai Bissantz is Senior Lecturer, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany . Hajo Holzmann is Professor, Fachbereich Mathematik und Informatik, Phillips-Universität Marburg, Hans-Meerweinstraße, 35032 Marburg, Germany
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28
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Abstract
Due to the presence of plastids, eukaryotic photosynthetic cells represent the most highly compartmentalized eukaryotic cells. This high degree of compartmentation requires the transport of solutes across intracellular membrane systems by specific membrane transporters. In this review, we summarize the recent progress on functionally characterized intracellular plant membrane transporters and we link transporter functions to Arabidopsis gene identifiers and to the transporter classification system. In addition, we outline challenges in further elucidating the plant membrane permeome and we provide an outline of novel approaches for the functional characterization of membrane transporters.
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Affiliation(s)
- Nicole Linka
- Institute of Plant Biochemistry, Heinrich-Heine Universität Düsseldorf, Geb. 26.03.01, Universitätsstrasse 1, Düsseldorf, Germany
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29
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Studer A, Han X, Winkler FK, Tiefenauer LX. Formation of individual protein channels in lipid bilayers suspended in nanopores. Colloids Surf B Biointerfaces 2009; 73:325-31. [DOI: 10.1016/j.colsurfb.2009.06.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 05/29/2009] [Accepted: 06/02/2009] [Indexed: 11/16/2022]
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30
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Hansen JS, Perry M, Vogel J, Groth JS, Vissing T, Larsen MS, Geschke O, Emneús J, Bohr H, Nielsen CH. Large scale biomimetic membrane arrays. Anal Bioanal Chem 2009; 395:719-27. [DOI: 10.1007/s00216-009-3010-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 07/22/2009] [Accepted: 07/23/2009] [Indexed: 10/20/2022]
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31
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Nussio MR, Oncins G, Ridelis I, Szili E, Shapter JG, Sanz F, Voelcker NH. Nanomechanical Characterization of Phospholipid Bilayer Islands on Flat and Porous Substrates: A Force Spectroscopy Study. J Phys Chem B 2009; 113:10339-47. [DOI: 10.1021/jp811035g] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Matthew R. Nussio
- School of Chemistry, Physics and Earth Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5001, Australia, Scientific-Technical Services, Nanometric Techniques Unit, University of Barcelona, Soler i Sabaris 1, 08028 Barcelona, Spain, Nanoprobes and Nanoswitches, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 13,08028 Barcelona, Spain, Department of Physical Chemistry, Chemistry Faculty, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, and CIBER
| | - Gerard Oncins
- School of Chemistry, Physics and Earth Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5001, Australia, Scientific-Technical Services, Nanometric Techniques Unit, University of Barcelona, Soler i Sabaris 1, 08028 Barcelona, Spain, Nanoprobes and Nanoswitches, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 13,08028 Barcelona, Spain, Department of Physical Chemistry, Chemistry Faculty, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, and CIBER
| | - Ingrid Ridelis
- School of Chemistry, Physics and Earth Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5001, Australia, Scientific-Technical Services, Nanometric Techniques Unit, University of Barcelona, Soler i Sabaris 1, 08028 Barcelona, Spain, Nanoprobes and Nanoswitches, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 13,08028 Barcelona, Spain, Department of Physical Chemistry, Chemistry Faculty, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, and CIBER
| | - Endre Szili
- School of Chemistry, Physics and Earth Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5001, Australia, Scientific-Technical Services, Nanometric Techniques Unit, University of Barcelona, Soler i Sabaris 1, 08028 Barcelona, Spain, Nanoprobes and Nanoswitches, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 13,08028 Barcelona, Spain, Department of Physical Chemistry, Chemistry Faculty, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, and CIBER
| | - Joseph G. Shapter
- School of Chemistry, Physics and Earth Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5001, Australia, Scientific-Technical Services, Nanometric Techniques Unit, University of Barcelona, Soler i Sabaris 1, 08028 Barcelona, Spain, Nanoprobes and Nanoswitches, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 13,08028 Barcelona, Spain, Department of Physical Chemistry, Chemistry Faculty, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, and CIBER
| | - Fausto Sanz
- School of Chemistry, Physics and Earth Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5001, Australia, Scientific-Technical Services, Nanometric Techniques Unit, University of Barcelona, Soler i Sabaris 1, 08028 Barcelona, Spain, Nanoprobes and Nanoswitches, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 13,08028 Barcelona, Spain, Department of Physical Chemistry, Chemistry Faculty, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, and CIBER
| | - Nicolas H. Voelcker
- School of Chemistry, Physics and Earth Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5001, Australia, Scientific-Technical Services, Nanometric Techniques Unit, University of Barcelona, Soler i Sabaris 1, 08028 Barcelona, Spain, Nanoprobes and Nanoswitches, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 13,08028 Barcelona, Spain, Department of Physical Chemistry, Chemistry Faculty, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain, and CIBER
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Mey I, Stephan M, Schmitt EK, Müller MM, Ben Amar M, Steinem C, Janshoff A. Local Membrane Mechanics of Pore-Spanning Bilayers. J Am Chem Soc 2009; 131:7031-9. [DOI: 10.1021/ja809165h] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ingo Mey
- Institute of Physical Chemistry, University of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Laboratoire de Physique Statistique de l’Ecole Normale Supérieure (UMR 8550), associé aux Universités Paris 6 et Paris 7 et au CNRS; 24, rue Lhomond, 75005 Paris, France
| | - Milena Stephan
- Institute of Physical Chemistry, University of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Laboratoire de Physique Statistique de l’Ecole Normale Supérieure (UMR 8550), associé aux Universités Paris 6 et Paris 7 et au CNRS; 24, rue Lhomond, 75005 Paris, France
| | - Eva K. Schmitt
- Institute of Physical Chemistry, University of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Laboratoire de Physique Statistique de l’Ecole Normale Supérieure (UMR 8550), associé aux Universités Paris 6 et Paris 7 et au CNRS; 24, rue Lhomond, 75005 Paris, France
| | - Martin Michael Müller
- Institute of Physical Chemistry, University of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Laboratoire de Physique Statistique de l’Ecole Normale Supérieure (UMR 8550), associé aux Universités Paris 6 et Paris 7 et au CNRS; 24, rue Lhomond, 75005 Paris, France
| | - Martine Ben Amar
- Institute of Physical Chemistry, University of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Laboratoire de Physique Statistique de l’Ecole Normale Supérieure (UMR 8550), associé aux Universités Paris 6 et Paris 7 et au CNRS; 24, rue Lhomond, 75005 Paris, France
| | - Claudia Steinem
- Institute of Physical Chemistry, University of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Laboratoire de Physique Statistique de l’Ecole Normale Supérieure (UMR 8550), associé aux Universités Paris 6 et Paris 7 et au CNRS; 24, rue Lhomond, 75005 Paris, France
| | - Andreas Janshoff
- Institute of Physical Chemistry, University of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany, Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany, and Laboratoire de Physique Statistique de l’Ecole Normale Supérieure (UMR 8550), associé aux Universités Paris 6 et Paris 7 et au CNRS; 24, rue Lhomond, 75005 Paris, France
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Böcker M, Muschter S, Schmitt EK, Steinem C, Schäffer TE. Imaging and patterning of pore-suspending membranes with scanning ion conductance microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:3022-3028. [PMID: 19437710 DOI: 10.1021/la8034227] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Nano-BLMs (black lipid membranes) suspending the pores of highly ordered porous silicon substrates have been proven useful for functional investigations of ion channel proteins by electrical readouts. With the aim to monitor the resistive behavior of nano-BLMs spatially resolved in a contact-free manner, we report here on the visualization of nano-BLMs by means of scanning ion conductance microscopy (SICM). Silicon surfaces with highly ordered pore arrays were coated with a gold layer and functionalized with octadecanethiol before a droplet of 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) (2% w/v) dissolved in n-decane was applied. The topography of DPhPC membranes suspending the pores was stably imaged for hours without mechanical contact using SICM. This suggests that SICM provides a significant advantage over atomic force microscopy, where mechanical interactions occur that easily damage the suspended membranes. Dynamic processes such as spreading and rupturing of membranes were spatially and temporally resolved. Furthermore, SICM was used to individually manipulate membranes suspending single pores, thereby writing lithographic patterns into the lipid. The process of local membrane manipulation was correlated to a characteristic signature in the simultaneously recorded ion current. The results show that SICM is well-suited both for contact-free imaging of soft suspended membranes and for local membrane manipulation.
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Affiliation(s)
- Matthias Böcker
- Institute of Applied Physics, University of Erlangen-Nuremberg, Staudtstr. 7, Bldg. A3, 91058 Erlangen, Germany
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Poulos JL, Jeon TJ, Damoiseaux R, Gillespie EJ, Bradley KA, Schmidt JJ. Ion channel and toxin measurement using a high throughput lipid membrane platform. Biosens Bioelectron 2008; 24:1806-10. [PMID: 18849158 DOI: 10.1016/j.bios.2008.08.041] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 07/30/2008] [Accepted: 08/14/2008] [Indexed: 11/19/2022]
Abstract
Measurements of ion channels are important for scientific, sensing and pharmaceutical applications. Reconstitution of ion channels into lipid vesicles and planar lipid bilayers for measurement at the single molecule level is a laborious and slow process incompatible with the high throughput methods and equipment used for sensing and drug discovery. A recently published method of lipid bilayer formation mechanically combines lipid monolayers self-assembled at the interfaces of aqueous and apolar phases. We have expanded on this method by vertically orienting these phases and using gravity as the driving force to combine the monolayers. As this method only requires fluid dispensation, it is trivially integrated with high throughput automated liquid-handling robotics. In a proof-of-concept demonstration, we created over 2200 lipid bilayers in 3h. We show single molecule measurements of technologically and physiologically relevant ion channels incorporated into lipid bilayers formed with this method.
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Affiliation(s)
- Jason L Poulos
- Department of Bioengineering, University of California, Los Angeles, USA
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Suzuki H, Takeuchi S. Microtechnologies for membrane protein studies. Anal Bioanal Chem 2008; 391:2695-702. [PMID: 18335213 PMCID: PMC2516541 DOI: 10.1007/s00216-008-1916-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 01/22/2008] [Accepted: 01/23/2008] [Indexed: 11/29/2022]
Abstract
Despite the rapid and enormous progress in biotechnologies, the biochemical analysis of membrane proteins is still a difficult task. The presence of the large hydrophobic region buried in the lipid bilayer membrane (transmembrane domain) makes it difficult to analyze membrane proteins in standard assays developed for water-soluble proteins. To handle membrane proteins, the lipid bilayer membrane may be used as a platform to sustain their functionalities. Relatively slow progress in developing micro total analysis systems (microTAS) for membrane protein analysis directly reflects the difficulty of handling lipid membranes, which is a common problem in bulk measurement technologies. Nonetheless, researchers are continuing to develop efficient and sensitive analytical microsystems for the study of membrane proteins. Here, we review the latest developments, which enable detection of events caused by membrane proteins, such as ion channel current, membrane transport, and receptor/ligand interaction, by utilizing microfabricated structures. High-throughput and highly sensitive detection systems for membrane proteins are now becoming a realistic goal. Although most of these systems are still in the early stages of development, we believe this field will become one of the most important applications of microTAS for pharmaceutical and clinical screenings as well as for basic biochemical research.
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Affiliation(s)
- Hiroaki Suzuki
- Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo, 153-8505 Japan
- Graduate School of Information Science and Technology, Osaka University, Yamadaoka 2-1, Suita, Osaka, 565-0871 Japan
| | - Shoji Takeuchi
- Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo, 153-8505 Japan
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She F, Gao W, Peng Z, Hodgson P, Kong L. Micro- and nano-characterization of membrane materials. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.jcice.2008.01.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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38
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Nano for bio: Nanopore arrays for stable and functional lipid bilayer membranes (Mini Review). Biointerphases 2008; 3:FA74. [DOI: 10.1116/1.2912932] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Chapter 3 Pore-Suspending Membranes on Highly Ordered Porous Alumina and Porous Silicon Substrates: Preparation, Characterization, and Application. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/s1554-4516(08)00003-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Weiskopf D, Schmitt EK, Klühr MH, Dertinger SK, Steinem C. Micro-BLMs on highly ordered porous silicon substrates: rupture process and lateral mobility. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:9134-9. [PMID: 17655338 DOI: 10.1021/la701080u] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
In a recent paper, we hypothesized that the continuous increase in membrane conductance observed for nano-BLMs is the result of an independent rupturing of single membranes or membrane patches covering the pores of the porous material. To prove this hypothesis, we prepared micro-BLMs on porous silicon substrates with a pore size of 7 mum. The upper surface of the silicon substrate was coated with a gold layer, followed by the chemisorption of 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) and subsequent addition of a droplet of 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) dissolved in n-decane. The lipid membranes were fluorescently labeled and investigated by means of fluorescence microscopy and impedance spectroscopy. Impedance spectroscopy revealed the formation of pore-suspending bilayers with high membrane resistance. Increases in membrane capacitance and membrane conductance were observed. This increase in membrane conductance could be unambiguously related to the individual rupturing of membranes suspending the pores of the porous material as visualized by means of fluorescence microscopy. Moreover, by fluorescence recovery after photobleaching experiments, we investigated the lateral mobility of the lipids within the micro-BLMs leading to a mean effective diffusion coefficient of Deff = (14 +/- 1) microm2/s.
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Affiliation(s)
- Daniela Weiskopf
- Institut für Organische und Biomolekulare Chemie, Georg-August Universität, Göttingen, Germany
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41
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Abstract
Free-standing lipid bilayer membranes can be formed on small apertures (60 nm diameter) on highly ordered porous alumina substrates. The formation process of the membranes on a 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol submonolayer was followed by impedance spectroscopy. After lipid bilayers had thinned, the reconstitution and ionic conducting properties of the outer membrane protein OmpF of E. coli were monitored using single-channel recordings. The characteristic conductance states of the three monomers, fast kinetics, and subconductance states were observed. Blockade of the ion flow as a result of interaction of the antibiotic ampicillin with the protein was verified, indicating the full functionality of the protein channel in nanometer-scale bilayer membranes.
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Affiliation(s)
- Eva K Schmitt
- Institut für Analytische Chemie, Chemo- und Biosensorik, Universität Regensburg, 93040 Regensburg, Germany
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42
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Janshoff A, Steinem C. Transport across artificial membranes–an analytical perspective. Anal Bioanal Chem 2006; 385:433-51. [PMID: 16598461 DOI: 10.1007/s00216-006-0305-9] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2005] [Revised: 12/18/2005] [Accepted: 01/07/2006] [Indexed: 11/25/2022]
Abstract
Biosensors that make use of transport processes across lipid membranes are very rare even though a stimulus, the binding of a single analyte molecule, can enhance the sensor response manifold if the analyte leads to the transport of more than one ion or molecule across the membrane. Prerequisite for a proper function of such membrane based biosensors is the formation of lipid bilayers attached to a support that allow for the insertion of membrane peptides and proteins in a functional manner. In this review, the current state of the art technologies to obtain lipid membranes on various supports are described. Solid supported membranes on transparent and electrically conducting surfaces, lipid bilayers on micromachined apertures and on porous materials are discussed. The focus lies on the applicability of such membranes for the investigation of transport phenomena across lipid bilayers facilitated by membrane embedded peptides, channel proteins and transporters. Carriers and channel forming peptides, which are easy to handle and rather robust, are used frequently to build up membrane based biosensors. However, channel forming proteins and transporters are more difficult to insert functionally and thus, there are yet only few examples that demonstrate the applicability of such systems as biosensor devices.
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Affiliation(s)
- Andreas Janshoff
- Institut für Physikalische Chemie, Johannes-Gutenberg Universität, Jakob-Welder Weg 11, 55128 Mainz, Germany
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43
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Danelon C, Perez JB, Santschi C, Brugger J, Vogel H. Cell membranes suspended across nanoaperture arrays. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:22-5. [PMID: 16378393 DOI: 10.1021/la052387v] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We present a method for spreading large (>100 microm(2)) cell membrane fragments across nanoapertures in planar supports. Electron-beam and focused-ion-beam lithography were used to fabricate arrays of 50-600 nm diameter holes in free-standing silicon nitride (SiN) solid films 100-500 nm thick. By pressing adhering live cells onto the nanostructured SiN surface and then removing them, planar cell membrane sheets (CMSs) were transferred in a well-defined orientation onto the SiN support. We demonstrate the accessibility to both extracellular and intracellular surfaces of CMSs by targeting membrane constituents side-specifically with fluorescent markers. Our approach is of interest for studying ligand-receptor interactions using optical, electrical, and scanning probe techniques at the single-molecule level.
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Affiliation(s)
- Christophe Danelon
- Laboratory of Physical Chemistry of Polymers and Membranes, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
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