1
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Qiao F, Wang S, He J, Hung W, Ma X, Gong P, Li J, Sun T, De Souza C, Zhang L, Lin K. Investigating the role of membrane lipid composition differences on spray drying survival in Lactobacillus bulgaricus using non-targeted Lipidomics. Food Chem 2024; 459:140336. [PMID: 39003859 DOI: 10.1016/j.foodchem.2024.140336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 06/27/2024] [Accepted: 07/02/2024] [Indexed: 07/16/2024]
Abstract
The cell membrane, consisting of a phospholipid bilayer, is an important defense system of lactic acid bacteria (LAB) against adverse conditions. However, this membrane gets damaged during the process of spray drying of LAB into powder. In this study, two strains of Lactobacillus bulgaricus L9-7 and L4-2-12 with significantly different survival rates of about 22.49% and 0.43% after spray drying were explored at the cell membrane level. A total of 65 significantly different lipid species were screened from the cell membranes of two strains, with cardiolipin (CL) 15:1_22:6_24:0_28:0 being the crucial lipid species affecting membrane resistance. Finally, the KEGG enrichment analysis revealed that glycerophospholipid metabolism was the most predominant pathway, and eleven lipid species were annotated, including CL. Overall, this paper provides valuable insights into enhancing the heat tolerance of LAB.
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Affiliation(s)
- Fengzhi Qiao
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003, China
| | - Shaolei Wang
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003, China
| | - Jian He
- National Center of Technology Innovation for Dairy, Hohhot 010000, China
| | - Weilian Hung
- National Center of Technology Innovation for Dairy, Hohhot 010000, China
| | - Xia Ma
- National Center of Technology Innovation for Dairy, Hohhot 010000, China
| | - Pimin Gong
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003, China
| | - Jiadong Li
- Innochina Biotech Co., Ltd, Shanghai, 201400, China
| | - Ting Sun
- National Center of Technology Innovation for Dairy, Hohhot 010000, China
| | - Cristabelle De Souza
- Department of Stem Cell Research and Regenerative Medicine, School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Lanwei Zhang
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003, China.
| | - Kai Lin
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao, 266003, China.
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2
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Gavutis M, Schulze-Niemand E, Lee HH, Liedberg B, Stein M, Valiokas R. Bilayer lipid membrane formation on surface assemblies with sparsely distributed tethers. NANOSCALE 2023. [PMID: 37128711 DOI: 10.1039/d2nr07069c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A combined computational and experimental study of small unilamellar vesicle (SUV) fusion on mixed self-assembled monolayers (SAMs) terminated with different deuterated tether moieties (-(CD2)7CD3 or -(CD2)15CD3) is reported. Tethered bilayer lipid membrane (tBLM) formation of synthetic 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine was initially probed on SAMs with controlled tether (d-alkyl tail) surface densities and lateral molecular packing using quartz crystal microbalance with dissipation monitoring (QCM-D). Long time-scale coarse-grained molecular dynamics (MD) simulations were then employed to elucidate the mechanisms behind the interaction between the SUVs and the different phases formed by the -(CD2)7CD3 and -(CD2)15CD3 tethers. Furthermore, a series of real time kinetics was recorded under different osmotic conditions using QCM-D to determine the accumulated lipid mass and for probing the fusion process. It is shown that the key factors driving the SUV fusion and tBLM formation on this type of surfaces involve tether insertion into the SUVs along with vesicle deformation. It is also evident that surface densities of the tethers as small as a few mol% are sufficient to obtain stable tBLMs with a high reproducibility. The described "sparsely tethered" tBLM system can be advantageous in studying different biophysical phenomena, such as membrane protein insertion, effects of receptor clustering, and raft formation.
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Affiliation(s)
- Martynas Gavutis
- Department of Nanoengineering, Center for Physical Sciences and Technology, Savanorių 231, 02300 Vilnius, Lithuania.
| | - Eric Schulze-Niemand
- Molecular Simulations and Design Group, Max Planck Institute for Dynamics of Complex Technical System, Magdeburg, Germany
- Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, 39120 Magdeburg, Germany
| | - Hung-Hsun Lee
- Division of Molecular Physics, Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
| | - Bo Liedberg
- Division of Molecular Physics, Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
| | - Matthias Stein
- Molecular Simulations and Design Group, Max Planck Institute for Dynamics of Complex Technical System, Magdeburg, Germany
| | - Ramūnas Valiokas
- Department of Nanoengineering, Center for Physical Sciences and Technology, Savanorių 231, 02300 Vilnius, Lithuania.
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3
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Utesch T, Staffa J, Katz S, Yao G, Kozuch J, Hildebrandt P. Potential Distribution across Model Membranes. J Phys Chem B 2022; 126:7664-7675. [PMID: 36137267 DOI: 10.1021/acs.jpcb.2c05372] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Membrane models assembled on electrodes are widely used tools to study potential-dependent molecular processes at or in membranes. However, the relationship between the electrode potential and the potential across the membrane is not known. Here we studied lipid bilayers immobilized on mixed self-assembled monolayers (SAM) on Au electrodes. The mixed SAM was composed of thiol derivatives of different chain lengths such that between the islands of the short one, mercaptobenzonitrile (MBN), and the tethered lipid bilayer an aqueous compartment was formed. The nitrile function of MBN, which served as a reporter group for the vibrational Stark effect (VSE), was probed by surface-enhanced infrared absorption spectroscopy to determine the local electric field as a function of the electrode potential for pure MBN, mixed SAM, and the bilayer system. In parallel, we calculated electric fields at the VSE probe by molecular dynamics (MD) simulations for different charge densities on the metal, thereby mimicking electrode potential changes. The agreement with the experiments was very good for the calculations of the pure MBN SAM and only slightly worse for the mixed SAM. The comparison with the experiments also guided the design of the bilayer system in the MD setups, which were selected to calculate the electrode potential dependence of the transmembrane potential, a quantity that is not directly accessible by the experiments. The results agree very well with estimates in previous studies and thus demonstrate that the present combined experimental-theoretical approach is a promising tool for describing potential-dependent processes at biomimetic interfaces.
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Affiliation(s)
- Tillmann Utesch
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, D-13125 Berlin, Germany
| | - Jana Staffa
- Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Sagie Katz
- Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Guiyang Yao
- Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Jacek Kozuch
- Fachbereich Physik, Experimentelle Molekulare Biophysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.,Forschungsbau SupraFAB, Altensteinstr. 23a, D-14195 Berlin, Germany
| | - Peter Hildebrandt
- Institut für Chemie, Technische Universität Berlin, Sekr. PC14, Straße des 17. Juni 135, D-10623 Berlin, Germany
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4
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Pang B, Iqbal D, Sarfraz A, Biedermann PU, Erbe A. Differences in perchlorate adsorption to azobenzene monolayers on gold formed from thioacetate and thiol precursors. Z PHYS CHEM 2022. [DOI: 10.1515/zpch-2021-3143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Modification of metal surfaces with complex molecules opens interesting opportunities to build additional functionality into these surfaces. In this work, self assembled monolayers (SAMs) based on the same photoswitchable azobenzene motif but with different head groups have been synthesized and their SAMs on Au(111)/Si substrates have been characterized. 3-[(4-phenylazo)phenoxy]propyl thiol (PAPT) and its acetyl group protected analog, 3-[(4-phenylazo)phenoxy]propyl thioacetate (PAPA), have been synthesized. SAMs from PAPT and PAPA have been characterized by infrared (IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), ellipsometry and cyclic voltammetry (CV). The SAM-forming units of both SAMs are the same, as confirmed by IR and XPS, and the SAMs have similar surface coverage, as evidenced by analysis of the reductive desorption peaks in CVs. The tilt angle of the azobenzene moiety was ca. 75° with respect to the surface normal as determined by IR spectroscopy, i.e., the molecules are lying quite flat on the gold surface. Despite similar surface coverages, the CVs for PAPT in aqueous perchlorate solution show a typical perchlorate adsorption peak to gold, whereas the corresponding experiments with PAPA show no perchlorate adsorption at all. In conclusion, SAM formation can lead to an increase in the number of electrochemically accessible surface sites on the final, SAM covered surface. Whether the amount of such sites increases or decreases, depends on the precursor. The precursor most likely affects the adsorption mechanism and thus the atomic surface structure of the metal at the metal/SAM interface. Thus, details of the SAM formation mechanism, which is affected by the precursor used, can have quite strong effects on the electrochemical properties, and likely also electrocatalytic properties, of the resulting modified surface.
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Affiliation(s)
- Beibei Pang
- Max-Planck-Institut für Eisenforschung GmbH , Max-Planck-Str., 1, 40237 Düsseldorf , Germany
| | - Danish Iqbal
- Max-Planck-Institut für Eisenforschung GmbH , Max-Planck-Str., 1, 40237 Düsseldorf , Germany
| | - Adnan Sarfraz
- Max-Planck-Institut für Eisenforschung GmbH , Max-Planck-Str., 1, 40237 Düsseldorf , Germany
| | - P. Ulrich Biedermann
- Max-Planck-Institut für Eisenforschung GmbH , Max-Planck-Str., 1, 40237 Düsseldorf , Germany
| | - Andreas Erbe
- Department of Materials Science and Engineering , NTNU, Norwegian University of Science and Technology , 7491 Trondheim , Norway
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5
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Gabriunaite I, Valiuniene A, Ramanavicius S, Ramanavicius A. Biosensors Based on Bio-Functionalized Semiconducting Metal Oxides. Crit Rev Anal Chem 2022; 54:549-564. [PMID: 35714203 DOI: 10.1080/10408347.2022.2088226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Immobilization of biomaterials is a very important task in the development of biofuel cells and biosensors. Some semiconducting metal-oxide-based supporting materials can be used in these bioelectronics-based devices. In this article, we are reviewing some functionalization methods that are applied for the immobilization of biomaterials. The most significant attention is paid to the immobilization of biomolecules on the surface of semiconducting metal oxides. The improvement of biomaterials immobilization on metal oxides and analytical performance of biosensors by coatings based on conducting polymers, self-assembled monolayers and lipid membranes is discussed.
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Affiliation(s)
- Inga Gabriunaite
- Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Department of Physical Chemistry, Vilnius, Lithuania
| | - Ausra Valiuniene
- Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Department of Physical Chemistry, Vilnius, Lithuania
| | - Simonas Ramanavicius
- Centre for Physical Sciences and Technology, Department of Electrochemical Material Science, Vilnius, Lithuania
| | - Arunas Ramanavicius
- Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Department of Physical Chemistry, Vilnius, Lithuania
- Centre for Physical Sciences and Technology, Department of Electrochemical Material Science, Vilnius, Lithuania
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6
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Chirkov NS, Campbell RA, Michailov AV, Vlasov PS, Noskov BA. DNA Interaction with a Polyelectrolyte Monolayer at Solution-Air Interface. Polymers (Basel) 2021; 13:2820. [PMID: 34451359 PMCID: PMC8400178 DOI: 10.3390/polym13162820] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 01/17/2023] Open
Abstract
The formation of ordered 2D nanostructures of double stranded DNA molecules at various interfaces attracts more and more focus in medical and engineering research, but the underlying intermolecular interactions still require elucidation. Recently, it has been revealed that mixtures of DNA with a series of hydrophobic cationic polyelectrolytes including poly(N,N-diallyl-N-hexyl-N-methylammonium) chloride (PDAHMAC) form a network of ribbonlike or threadlike aggregates at the solution-air interface. In the present work, we adopt a novel approach to confine the same polyelectrolyte at the solution-air interface by spreading it on a subphase with elevated ionic strength. A suite of techniques-rheology, microscopy, ellipsometry, and spectroscopy-are applied to gain insight into main steps of the adsorption layer formation, which results in non-monotonic kinetic dependencies of various surface properties. A long induction period of the kinetic dependencies after DNA is exposed to the surface film results only if the initial surface pressure corresponds to a quasiplateau region of the compression isotherm of a PDAHMAC monolayer. Despite the different aggregation mechanisms, the micromorphology of the mixed PDAHMAC/DNA does not depend noticeably on the initial surface pressure. The results provide new perspective on nanostructure formation involving nucleic acids building blocks.
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Affiliation(s)
- Nikolay S. Chirkov
- Institute of Chemistry, Saint Petersburg State University, 198504 St. Petersburg, Russia; (N.S.C.); (A.V.M.); (P.S.V.)
| | - Richard A. Campbell
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK;
| | - Alexander V. Michailov
- Institute of Chemistry, Saint Petersburg State University, 198504 St. Petersburg, Russia; (N.S.C.); (A.V.M.); (P.S.V.)
| | - Petr S. Vlasov
- Institute of Chemistry, Saint Petersburg State University, 198504 St. Petersburg, Russia; (N.S.C.); (A.V.M.); (P.S.V.)
| | - Boris A. Noskov
- Institute of Chemistry, Saint Petersburg State University, 198504 St. Petersburg, Russia; (N.S.C.); (A.V.M.); (P.S.V.)
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7
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Wang X, Zhang Y, Bi H, Han X. Supported lipid bilayer membrane arrays on micro-patterned ITO electrodes. RSC Adv 2016. [DOI: 10.1039/c6ra10294h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Lipid bilayer arrays were formed on micropatterned ITO electrodes. With this bilayer array platform both the fluorescence microscopy and electrochemical detection can be realized to explore the biophysical properties of cell membrane.
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Affiliation(s)
- Xuejing Wang
- State Key Laboratory of Urban Water Resource and Environment
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150001
- China
| | - Ying Zhang
- State Key Laboratory of Urban Water Resource and Environment
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150001
- China
| | - Hongmei Bi
- State Key Laboratory of Urban Water Resource and Environment
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150001
- China
| | - Xiaojun Han
- State Key Laboratory of Urban Water Resource and Environment
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150001
- China
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8
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Nayak S, Erbe A. Mechanism of the potential-triggered surface transformation of germanium in acidic medium studied by ATR-IR spectroscopy. Phys Chem Chem Phys 2016; 18:25100-25109. [DOI: 10.1039/c6cp04514f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
During the electrochemical surface transformation of Ge(100) and Ge(111) surfaces from an –OH to an –H terminated surface, different potential dependent transient species are observed.
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Affiliation(s)
- Simantini Nayak
- Max-Planck-Institut für Eisenforschung GmbH
- Düsseldorf
- Germany
| | - Andreas Erbe
- Max-Planck-Institut für Eisenforschung GmbH
- Düsseldorf
- Germany
- Department of Materials Science and Engineering
- NTNU
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9
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10
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Blakeston AC, Alswieleh AM, Heath GR, Roth JS, Bao P, Cheng N, Armes SP, Leggett GJ, Bushby RJ, Evans SD. New poly(amino acid methacrylate) brush supports the formation of well-defined lipid membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015. [PMID: 25746444 DOI: 10.1021/la504163s.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel poly(amino acid methacrylate) brush comprising zwitterionic cysteine groups (PCysMA) was utilized as a support for lipid bilayers. The polymer brush provides a 12-nm-thick cushion between the underlying hard support and the aqueous phase. At neutral pH, the zeta potential of the PCysMA brush was ∼-10 mV. Cationic vesicles containing >25% DOTAP were found to form a homogeneous lipid bilayer, as determined by a combination of surface analytical techniques. The lipid mobility as measured by FRAP (fluorescence recovery after photobleaching) gave diffusion coefficients of ∼1.5 μm(2) s(-1), which are comparable to those observed for lipid bilayers on glass substrates.
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Affiliation(s)
- Anita C Blakeston
- †Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Abdullah M Alswieleh
- ‡Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - George R Heath
- †Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Johannes S Roth
- †Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Peng Bao
- †Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Nan Cheng
- ‡Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Steven P Armes
- ‡Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Graham J Leggett
- ‡Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Richard J Bushby
- †Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Stephen D Evans
- †Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
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11
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Blakeston A, Alswieleh AM, Heath GR, Roth JS, Bao P, Cheng N, Armes SP, Leggett GJ, Bushby RJ, Evans SD. New poly(amino acid methacrylate) brush supports the formation of well-defined lipid membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3668-77. [PMID: 25746444 PMCID: PMC4444997 DOI: 10.1021/la504163s] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 01/29/2015] [Indexed: 05/19/2023]
Abstract
A novel poly(amino acid methacrylate) brush comprising zwitterionic cysteine groups (PCysMA) was utilized as a support for lipid bilayers. The polymer brush provides a 12-nm-thick cushion between the underlying hard support and the aqueous phase. At neutral pH, the zeta potential of the PCysMA brush was ∼-10 mV. Cationic vesicles containing >25% DOTAP were found to form a homogeneous lipid bilayer, as determined by a combination of surface analytical techniques. The lipid mobility as measured by FRAP (fluorescence recovery after photobleaching) gave diffusion coefficients of ∼1.5 μm(2) s(-1), which are comparable to those observed for lipid bilayers on glass substrates.
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Affiliation(s)
- Anita
C. Blakeston
- Molecular
and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United
Kingdom
| | | | - George R. Heath
- Molecular
and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United
Kingdom
| | - Johannes S. Roth
- Molecular
and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United
Kingdom
| | - Peng Bao
- Molecular
and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United
Kingdom
| | - Nan Cheng
- Department
of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Steven P. Armes
- Department
of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Graham J. Leggett
- Department
of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Richard J. Bushby
- Molecular
and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United
Kingdom
| | - Stephen D. Evans
- Molecular
and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United
Kingdom
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12
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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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13
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In situ infrared spectroscopic investigation of intermediates in the electrochemical oxygen reduction on n-Ge(100) in alkaline perchlorate and chloride electrolyte. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.05.133] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Nayak S, Biedermann PU, Stratmann M, Erbe A. A mechanistic study of the electrochemical oxygen reduction on the model semiconductor n-Ge(100) by ATR-IR and DFT. Phys Chem Chem Phys 2013; 15:5771-81. [DOI: 10.1039/c2cp43909c] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Kozuch J, Steinem C, Hildebrandt P, Millo D. Combined Electrochemistry and Surface-Enhanced Infrared Absorption Spectroscopy of Gramicidin A Incorporated into Tethered Bilayer Lipid Membranes. Angew Chem Int Ed Engl 2012; 51:8114-7. [DOI: 10.1002/anie.201203214] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Indexed: 11/06/2022]
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16
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Kozuch J, Steinem C, Hildebrandt P, Millo D. Kombinierte elektrochemische und oberflächenverstärkte IR-absorptionsspektroskopische Untersuchung von Gramicidin A in trägerfixierten Lipiddoppelschichtmembranen. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201203214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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Lazzara TD, Carnarius C, Kocun M, Janshoff A, Steinem C. Separating attoliter-sized compartments using fluid pore-spanning lipid bilayers. ACS NANO 2011; 5:6935-6944. [PMID: 21797231 DOI: 10.1021/nn201266e] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Anodic aluminum oxide (AAO) is a porous material having aligned cylindrical compartments with 55-60 nm diameter pores, and being several micrometers deep. A protocol was developed to generate pore-spanning fluid lipid bilayers separating the attoliter-sized compartments of the nanoporous material from the bulk solution, while preserving the optical transparency of the AAO. The AAO was selectively functionalized by silane chemistry to spread giant unilamellar vesicles (GUVs) resulting in large continuous membrane patches covering the pores. Formation of fluid single lipid bilayers through GUV rupture could be readily observed by fluorescence microscopy and further supported by conservation of membrane surface area, before and after GUV rupture. Fluorescence recovery after photobleaching gave low immobile fractions (5-15%) and lipid diffusion coefficients similar to those found for bilayers on silica. The entrapment of molecules within the porous underlying cylindrical compartments, as well as the exclusion of macromolecules from the nanopores, demonstrate the barrier function of the pore-spanning membranes and could be investigated in three-dimensions using confocal laser scanning fluorescence imaging.
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Affiliation(s)
- Thomas D Lazzara
- Institute of Organic and Biomolecular Chemistry, Tammannstrasse 2, 37077 Göttingen, Germany
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18
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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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19
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Reithmeier M, Erbe A. Application of thin-film interference coatings in infrared reflection spectroscopy of organic samples in contact with thin metal films. APPLIED OPTICS 2011; 50:C301-C308. [PMID: 21460955 DOI: 10.1364/ao.50.00c301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A thin dielectric IR-transparent interlayer is introduced between an IR-transparent medium of incidence and a thin metal film. The interlayer increases the intensity of light on the metal/sample interface at certain wavenumbers. By computations, the reflectivities of the system "calcium fluoride (CaF)-germanium (Ge)-gold (Au) sample" are analyzed as a function of incidence angle and Ge layer thickness. Absorbance spectra with acetonitrile as a sample are recorded for different angles of incidence and polarizations and compared to computations. A characteristic feature of the absorbance spectra is the occurrence of interference fringes distributed between 1000 and 6000 cm(-1), i.e., over the complete mid-IR wavelength range into the near-IR. These fringes could be used in analytical spectroscopy.
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20
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Native E. coli inner membrane incorporation in solid-supported lipid bilayer membranes. Biointerphases 2010; 3:FA59. [PMID: 20408670 DOI: 10.1116/1.2896113] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Solid-supported bilayer lipid membranes (SBLMs) containing membrane protein have been generated through a simple lipid dilution technique. SBLM formation from mixtures of native Escherichia coli bacterial inner membrane (IM) vesicles diluted with egg phosphatidylcholine (egg PC) vesicles has been explored with dissipation enhanced quartz crystal microbalance (QCM-D), atomic force microscopy (AFM), attenuated total internal-reflection Fourier-transform infrared spectroscopy (ATR-FTIR), and fluorescence recovery after photobleaching (FRAP). QCM-D studies reveal that SBLM formation from vesicle mixtures ranging between 0% and 100% IM can be divided into two regimes. Samples with < or = 40% IM form SBLMs, while samples of greater IM fractions are dominated by vesicle adsorption. FRAP experiments showed that the bilayers formed from mixed vesicles with < or = 40% IM were fluid, and comprised a mixture of both egg PC and IM. ATR-FTIR measurements on SBLMs membranes formed with 30% IM confirm that protein is present. SBLM formation was also explored as a function of temperature by QCM-D and FRAP. For samples of 30% IM, QCM-D data show a decreased mass and viscoelasticity at elevated temperatures, and an increased fluidity is observed by FRAP measurements. These results suggest improved biomimetic characteristics can be obtained by forming and maintaining the system at, or close to, 37 degrees C.
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21
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Reithmeier M, Erbe A. Dielectric interlayers for increasing the transparency of metal films for mid-infrared attenuated total reflection spectroscopy. Phys Chem Chem Phys 2010; 12:14798-803. [DOI: 10.1039/c0cp01125h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Reimhult E, Baumann MK, Kaufmann S, Kumar K, Spycher PR. Advances in nanopatterned and nanostructured supported lipid membranes and their applications. Biotechnol Genet Eng Rev 2010; 27:185-216. [DOI: 10.1080/02648725.2010.10648150] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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23
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A Cholesterol-Based Tether for Creating Photopatterned Lipid Membrane Arrays on both a Silica and Gold Surface. Chemistry 2009; 15:6363-70. [DOI: 10.1002/chem.200900404] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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24
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Han X, Cheetham MR, Sheikh K, Olmsted PD, Bushby RJ, Evans SD. Manipulation and charge determination of proteins in photopatterned solid supported bilayers. Integr Biol (Camb) 2008; 1:205-11. [PMID: 20023804 DOI: 10.1039/b815601h] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This work demonstrates the use of deep UV micropatterned chlorotrimethylsilane (TMS) monolayers to support lipid membranes on SiO(2) surfaces. After immersing such a patterned surface into a solution containing small unilamellar vesicles of egg PC, supported bilayer lipid membranes were formed on the hydrophilic, photolyzed regions and lipid monolayer over the hydrophobic, non-photolyzed regions. A barrier between the lipid monolayer and bilayer regions served to stop charged lipids migrating between the two. This allows the system to be used to separate charged lipids or proteins by electrophoresis. Either oppositely charged fluorescence labeled lipids [Texas Red DHPE (negative charge) and D291 (positive charge)] or lipids with different charge numbers [Texas Red DHPE (one negative charge) and NBD PS (two negative charges)] can be separated. We have also studied the migration of streptavidin attached to a biotinylated lipid. Negatively charged streptavidin responds to the applied electric field by moving in the direction of electroosmotic flow, i.e. towards the negative electrode. However the direction of streptavidin movement can be controlled by altering the difference in zeta potential between that of the streptavidin (zeta(1)) and the lipid membrane (zeta(2)). If zeta(1) > zeta(2), streptavidin moves to the negative electrode, while if zeta(1) < zeta(2), streptavidin moves to the positive electrode. This balance was manipulated by adding positively charged lipid DOTAP to the membrane. After measuring the average drift velocity of streptavidin as a function of DOTAP concentration, the point where zeta(1) approximately zeta(2) was found. At this point zeta(1) was calculated to be -9.8 mV which is in good agreement with the value of -13 mV from force measurements and corresponds to a charge of -2e per streptavidin, thus demonstrating the applicability of this method for determining protein charge.
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Affiliation(s)
- Xiaojun Han
- School of Physics and Astronomy, University of Leeds, Leeds, UK
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25
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Schmitt EK, Nurnabi M, Bushby RJ, Steinem C. Electrically insulating pore-suspending membranes on highly ordered porous obtained from vesicle spreading. SOFT MATTER 2008; 4:250-253. [PMID: 32907236 DOI: 10.1039/b716723g] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Pore-suspending membranes on porous alumina substrates with pore diameters of 60 nm were prepared by fusion of vesicles on a (cholesterylpolyethylenoxy)thiol-functionalized surface, and their functionality demonstrated by the activity of the proton pump bacteriorhodopsin.
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Affiliation(s)
- Eva K Schmitt
- Institut für Organische und Biomolekulare Chemie, Georg-August Universität, Tammannstr. 2, 37077, Göttingen, Germany.
| | - Mohammad Nurnabi
- Centre for Self-Organising Molecular Systems, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Richard J Bushby
- Centre for Self-Organising Molecular Systems, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Claudia Steinem
- Institut für Organische und Biomolekulare Chemie, Georg-August Universität, Tammannstr. 2, 37077, Göttingen, Germany.
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