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Han Y, Chen L, Yang D. Antibacterial activity and mechanism of a type-I ubiquitin from the clam Ruditapes philippinarum. J Invertebr Pathol 2021; 183:107602. [PMID: 33964303 DOI: 10.1016/j.jip.2021.107602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 04/10/2021] [Accepted: 04/12/2021] [Indexed: 11/15/2022]
Abstract
In the present study, a ubiquitin (designated as RpUbi) was identified and characterized from clam Ruditapes philippinarum. Phylogenetic analysis strongly suggested that RpUbi was a member of the ubiquitin family. In non-stimulated clams, RpUbi transcripts were constitutively expressed in all examined tissues, especially in the gills and hemocytes. After Vibrio anguillarum challenge, expression of RpUbi mRNA in hemocytes was significantly up-regulated. Recombinant RpUbi (rRpUbi) showed high antibacterial activity against Gram-positive and Gram-negative bacteria. Notably, membrane integrity and electrochemical assay indicated that rRpUbi could invade the inner layer. Moreover, DNA migration could be inhibited by rRpUbi in a concentration-dependent manner. In general, our results suggested that RpUbi played an important role in host defense against invading bacteria, perhaps through a DNA-binding process.
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Affiliation(s)
- Yijing Han
- Research and Development Center for Efficient Utilization of Coastal Bioresources, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Lizhu Chen
- Shandong Marine Resource and Environment Research Institute, Yantai 264006, PR China
| | - Dinglong Yang
- Muping Coastal Environment Research Station, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, PR China; Research and Development Center for Efficient Utilization of Coastal Bioresources, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, PR China.
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2
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Lv C, Han Y, Yang D, Zhao J, Wang C, Mu C. Antibacterial activities and mechanisms of action of a defensin from manila clam Ruditapes philippinarum. FISH & SHELLFISH IMMUNOLOGY 2020; 103:266-276. [PMID: 32439511 DOI: 10.1016/j.fsi.2020.05.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/28/2020] [Accepted: 05/09/2020] [Indexed: 06/11/2023]
Abstract
Defensins represent an evolutionary ancient family of antimicrobial peptides, which played an undeniably important role in host defense. In the present study, a defensin isoform was identified and characterized from manila clam Ruditapes philippinarum (designed as Rpdef1α). Multiple alignments and phylogenetic analysis suggested that Rpdef1α belonged to the defensin family. Quantitative RT-PCR and immunohistochemical analysis revealed that Rpdef1α transcripts and the encoding peptide were dominantly expressed in the tissues of gills and mantle. After Vibrio anguillarum challenge, the Rpdef1α transcripts were significantly up-regulated in gills of clams. In addition, rRpdef1α not only showed broad-spectrum antimicrobial activities towards Vibrio species, but also inhibited the formation of bacterial biofilms. Knockdown of Rpdef1α transcripts caused significant increase in the cumulative mortality of manila clams post V. anguillarum challenge. Membrane integrity, scanning electron microscopy analysis and electrochemical assay indicated that rRpdef1α was capable of causing bacterial membrane permeabilization and then resulted in cell death. Moreover, phagocytosis and chemotactic ability of hemocytes could be significantly enhanced after incubation with rRpdef1α. Overall, these results suggested that Rpdef1α could act as both antibacterial agent and opsonin to defend against the invading microorganisms in manila clam R. philippinarum.
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Affiliation(s)
- Chengjie Lv
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, 315832, PR China; Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo, 315832, PR China
| | - Yijing Han
- Research and Development Center for Efficient Utilization of Coastal Bioresources, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Dinglong Yang
- Research and Development Center for Efficient Utilization of Coastal Bioresources, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, PR China; Center for Ocean Mega-science, Chinese Academy of Sciences, Qingdao, Shandong, 266071, PR China.
| | - Jianmin Zhao
- Research and Development Center for Efficient Utilization of Coastal Bioresources, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, PR China; Center for Ocean Mega-science, Chinese Academy of Sciences, Qingdao, Shandong, 266071, PR China
| | - Chunlin Wang
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, 315832, PR China; Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo, 315832, PR China
| | - Changkao Mu
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, School of Marine Sciences, Ningbo University, Ningbo, 315832, PR China; Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculture, Ningbo, 315832, PR China.
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3
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Sacconi A, Tadini-Buoninsegni F, Tiribilli B, Margheri G. A Comparative Study of Phosphatidylcholine versus Phosphatidylserine-Based Solid Supported Membranes for the Preparation of Liposome-Rich Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:12183-12190. [PMID: 30217106 DOI: 10.1021/acs.langmuir.8b02397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Solid supported membranes (SSMs) are usually formed by an hybrid octadecanethiol/phosphatidylcholine (PC) bilayer supported by a gold electrode. Recently, it was shown that phosphatidylserine (PS) in place of PC can promote a more effective accumulation of lipid vesicles on the SSM surface when Ca2+ and Mg2+ ions are present in the external environment. Here we performed a detailed comparative study of the vesicle adsorption process onto PC- and PS-SSMs by employing surface plasmon resonance (SPR), electrochemical impedance spectroscopy (EIS), and atomic force microscopy (AFM). SPR analysis has demonstrated a higher affinity of the PS-SSM surface for the phospholipid vesicles. Both SPR and EIS measurements suggest that adsorption of lipid vesicles on the PC-SSM tends to a saturating value, whereas a continuous and progressive vesicle adsorption occurs on the PS-SSM surface following subsequent liposome additions. AFM analysis pointed out a systematic flattening of the adsorbed vesicles on the PS-SSM surface. We interpreted our results as due to the strong coordinating action of the high amount of divalent cations accumulated at the negatively charged PS-SSM surface, whereas a lower amount of cations is present on the dipolar PC-SSM surface, which can therefore adsorb only a limited number of vesicles.
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Affiliation(s)
- Alessio Sacconi
- Department of Chemistry "Ugo Schiff" , University of Florence , Via della Lastruccia 3-13 , 50019 Sesto Fiorentino , Italy
| | - Francesco Tadini-Buoninsegni
- Department of Chemistry "Ugo Schiff" , University of Florence , Via della Lastruccia 3-13 , 50019 Sesto Fiorentino , Italy
| | - Bruno Tiribilli
- Institute for Complex Systems , National Research Council , Via Madonna del Piano 10 , 50019 Sesto Fiorentino , Italy
| | - Giancarlo Margheri
- Institute for Complex Systems , National Research Council , Via Madonna del Piano 10 , 50019 Sesto Fiorentino , Italy
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4
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A comparative study on kinetics and substrate specificities of Phospholipase A 1 with Thermomyces lanuginosus lipase. J Colloid Interface Sci 2017; 488:149-154. [DOI: 10.1016/j.jcis.2016.10.058] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/20/2016] [Accepted: 10/20/2016] [Indexed: 11/22/2022]
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5
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Cui X, Jiang D, Diao P, Li J, Jia Z, Tong R, Wang X. Assessing the Apparent Effective Thickness of the Supported Hybrid Bilayer Membranes Consisting of Octadecanethiol and Phospholipid by ac Impedance Spectroscopy. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.199900077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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6
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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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7
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Amphotericin B ion channel mimetic sensor: A new type of potassium-selective sensor based on electrode-supported hybrid bilayer membranes. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2012.03.096] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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8
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Interaction between curcumin and mimetic biomembrane. SCIENCE CHINA-LIFE SCIENCES 2012; 55:527-32. [PMID: 22744183 DOI: 10.1007/s11427-012-4317-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 03/09/2012] [Indexed: 10/28/2022]
Abstract
Curcumin, a major bioactive compound in turmeric, has a broad spectrum of antioxidant, anticarcinogenic, antimutagenic and anti-inflammatory properties. At the molecular level, curcumin modulates many structurally unrelated membrane proteins through several signaling pathways. Curcumin has been suggested to change the properties of cell membranes and affect the membrane-bound proteins indirectly; however, the detailed mechanism has yet to be investigated. In this paper, self-assembled bilayer lipid membranes are artificially constructed on the surface of a gold electrode to mimic biomembranes, and interaction between the supported membranes and curcumin is studied electrochemically. Results show that curcumin interacts with the membranes strongly, in a concentration-dependent manner. At low concentrations, curcumin tends to insert into the outer monolayer only, while at high concentrations, it may also begin to penetrate the inner monolayer. The results obtained in this work may enhance our understanding of the effect of curcumin, and possibly flavonoids, on cell membranes and membrane proteins.
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Antibiotic association with phospholipid nano-assemblies: A comparison between Langmuir–Blodgett films and supported lipid bilayers. Colloids Surf A Physicochem Eng Asp 2008. [DOI: 10.1016/j.colsurfa.2008.02.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Vallejo A, Gervasi C. EIS studies of valinomycin-mediated K+ transport through supported lipid bilayers. J Electroanal Chem (Lausanne) 2007. [DOI: 10.1016/j.jelechem.2007.01.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Smith MB, Tong J, Genzer J, Fischer D, Kilpatrick PK. Effects of synthetic amphiphilic alpha-helical peptides on the electrochemical and structural properties of supported hybrid bilayers on gold. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:1919-27. [PMID: 16460128 DOI: 10.1021/la051104w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Amphiphilic alpha-helices were formed from designed synthetic peptides comprising alanine, phenylalanine, and lysine residues. The insertion of the alpha-helical peptides into hybrid bilayers assembled on gold was studied by a variety of methods to assess the resulting structural characteristics, such as electrical resistance and molecular orientation. Self-assembled monolayers (SAMs) of dodecanethiol (DDT); octadecanethiol (ODT); and 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) were formed on gold substrates with and without incorporated peptide. Supported hybrid bilayers and multilayers of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) were formed on SAMs by the "paint-freeze" method of bilayer formation. Modeling of electrochemical impedance spectroscopy data using equivalent electrochemical circuits revealed that the addition of peptide decreased dramatically the resistive element of the bilayer films while maintaining the value of the capacitive element, indicating successful incorporation of peptide into a well-formed bilayer. Near-edge X-ray absorption fine structure spectroscopy data provided evidence that the molecules in the SAMs and hybrid multilayers were ordered even in the presence of peptide. The peptide insertion into the SAM was confirmed by observing the pi* resonance peak correlating with phenylalanine and a peak in the nitrogen K-edge regime attributable to the peptide bond.
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Affiliation(s)
- Matthew B Smith
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Box 7905, Raleigh, North Carolina 27695-7905, USA
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12
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Jayaraman K, Okamoto K, Son SJ, Luckett C, Gopalani AH, Lee SB, English DS. Observing Capillarity in Hydrophobic Silica Nanotubes. J Am Chem Soc 2005; 127:17385-92. [PMID: 16332088 DOI: 10.1021/ja055535c] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The development of template-synthesized silica nanotubes has created a unique opportunity for studying confined fluids by providing nanometer-scale containers in which the inner diameter (i.d.) and surface chemistry can be systematically and independently varied. An interesting question to be answered is the following: do solvents wet nanometer-scale tubes in the same way they wet ordinary capillaries? To answer this question, we have conducted studies to explore the wettability of the hydrophobic interiors of individual nanotubes. In these studies, single nanotubes with i.d.'s of either 30 or 170 nm were investigated over a range of water/methanol mixtures. These studies provide a direct route for comparing wetting phenomena in nanotubes with conventional macroscopic theories of capillarity. Our observations reveal four important aspects of capillary wetting in the 30-170 nm regime, a size range where the application of the Young-Laplace theory has not been experimentally investigated for hydrophobic pores. They are (i) a sharp transition between wetting and nonwetting conditions induced by addition of a cosolvent, (ii) invariance of this transition between nanotubes of 30 and 170 nm pore diameter, (iii) failure of the Young-Laplace equation to accurately predict the cosolvent's (methanol) mol fraction where the transition occurs, and (iv) reversibility of the observed wetting. The first two aspects conform to conventional capillarity (Young-Laplace), but the latter two do not. These measurements were complemented with ensemble experiments. The difference between theory and experiment is likely due to reliance on macroscopic values of contact angles or to liquid-phase instability within the hydrophobic pore.
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Affiliation(s)
- Karthik Jayaraman
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
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13
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Wang E, Han X. Electrochemical Study of the Bilayer Lipid Membrane. ADVANCES IN PLANAR LIPID BILAYERS AND LIPOSOMES 2005. [DOI: 10.1016/s1554-4516(05)02009-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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14
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Electrochemical Methods and Their Application. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1554-4516(05)02001-6] [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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15
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Munro JC, Frank CW. In situ formation and characterization of poly(ethylene glycol)-supported lipid bilayers on gold surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:10567-10575. [PMID: 15544386 DOI: 10.1021/la048378o] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Inclusion of a polymer cushion between a lipid bilayer membrane and a solid surface has been suggested as a means to provide a soft, deformable layer that will allow for transmembrane protein insertion and mobility. In this study, mobile, tethered lipid bilayers were formed on a poly(ethylene glycol) (PEG) support via a two-step adsorption process. The PEG films were prepared by coadsorbing a heterofunctional, telechelic PEG lipopolymer (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-poly(ethylene glycol)-2000-N-[3-(2-(pyridyldithio)propionate]) (DSPE-PEG-PDP) and a nonlipid functionalized PEG-PDP from an ethanol/water mixture, as described in a previous paper (Munro, J. C.; Frank, C. W. Langmuir 2004, 20, 3339-3349). Then a two-step lipid adsorption strategy was used. First, lipids were adsorbed onto the PEG support from a hexane solution. Second, vesicles were adsorbed and fused on the surface to create a bilayer in an aqueous environment. Fluorescence recovery after photobleaching experiments show that this process results in mobile bilayers with diffusion coefficients on the order of 2 microm2/s. The mobility of the bilayers is decreased slightly by increasing the density of tethered lipids. The formation of bilayers, and not multilayer structures, is also confirmed by surface plasmon resonance, which was used to determine in situ film thickness, and by fluorimetry, which was used to determine quantitatively the fluorescence intensity for each 18 by 18 mm sample. Unfortunately, fluorescence microscopy also shows that there are large defects on the samples, which limits the utility of this system.
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Affiliation(s)
- Jeffrey C Munro
- Department of Chemical Engineering, Stanford University, Stanford, California 94305-5025, USA
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16
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Steady-state oxidation of cholesterol catalyzed by cholesterol oxidase in lipid bilayer membranes on platinum electrodes. Anal Chim Acta 2004. [DOI: 10.1016/j.aca.2004.03.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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17
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Han X, Wang L, Qi B, Yang X, Wang E. A Strategy for Constructing a Hybrid Bilayer Membrane Based on a Carbon Substrate. Anal Chem 2003; 75:6566-70. [PMID: 16465708 DOI: 10.1021/ac034592q] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We construct a hybrid bilayer membrane (HBM) on a new substrate-carbon electrode. It is an extension of HBM based on other substrates. Primary alkylamine was chemically modified onto the surface of a carbon electrode by electrochemical scans; thus, a monolayer was formed on the electrode. Because the alkane chains section is toward the outside, a hydrophobic surface was constructed. Then a lipid monolayer was spread on the hydrophobic surface of the carbon electrode. The formed HBM was characterized by electrochemical and ATR-FT-IR methods. From ATR-FT-IR results, the lipid order parameter (S) of 0.73 was obtained. This kind of hybrid membrane has the advantages of a lipid/alkanethiol HBM. A potential application of this HBM as a biosensor (detecting K+) was given.
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Affiliation(s)
- Xiaojun Han
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
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18
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Supported lipid bilayers lifted from the substrate by layer-by-layer polyion cushions on self-assembled monolayers. Colloids Surf B Biointerfaces 2003. [DOI: 10.1016/s0927-7765(02)00175-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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19
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Wang L, Song Y, Han X, Zhang B, Wang E. Growth of cationic lipid toward bilayer lipid membrane by solution spreading: scanning probe microscopy study. Chem Phys Lipids 2003; 123:177-85. [PMID: 12691850 DOI: 10.1016/s0009-3084(02)00195-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The growth of cationic lipid dioctadecyldimethylammonium bromide (DODAB) toward bilayer lipid membrane (BLM) by solution spreading on cleaved mica surface was studied by atomic force microscopy (AFM). Bilayer of DODAB was formed by exposing mica to a solution of DODAB in chloroform and subsequently immersing into potassium chloride solution for film developing. AFM studies showed that at the initial stage of the growth, the adsorbed molecules exhibited the small fractal-like aggregates. These aggregates grew up and expanded laterally into larger patches with time and experienced from monolayer to bilayer, finally a close-packed bilayer film (5.4+/-0.2 nm) was approached. AFM results of the film growth process indicated a growth mechanism of nucleation, growth and coalescence of dense submonolayer, it revealed the direct information about the film morphology and confirmed that solution spreading was an effective technique to prepare a cationic bilayer in a short time.
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Affiliation(s)
- Li Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
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20
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Vallejo AE, Gervasi CA. Impedance analysis of ion transport through gramicidin channels in supported lipid bilayers. Bioelectrochemistry 2002; 57:1-7. [PMID: 12049750 DOI: 10.1016/s1567-5394(01)00127-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Selectivity between monovalent cations and its sequence of conductivity in lipid bilayers doped with the antibiotic Gramicidin D (GD) were examined using EIS. Experiments were performed using lipid bilayers obtained from a lipid mixture of phosphatidylcholine and dimethyldioctadecylammonium chloride (DODAC). Lipid bilayers were supported on gold surfaces modified with a mercapto-carboxylic acid. The bilayers were formed by chemisorption of this last species to form the first monolayer on gold and subsequent fusion of unilamellar vesicles to form an external bilayer attached by electrostatic interactions. A mathematical expression for the impedance of the membrane processes was derived. Some predictions of the presented model were checked after fitting the experimental results in various electrolyte compositions.
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Affiliation(s)
- A E Vallejo
- Laboratorio de Ingeniería de Corrosión y Tecnología Electroquímica (LICTE), Facultad de Ingeniería, Universidad Nacional de La Plata, 1 y 47, 1900 La Plata, Argentina
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21
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Steinle ED, Mitchell DT, Wirtz M, Lee SB, Young VY, Martin CR. Ion channel mimetic micropore and nanotube membrane sensors. Anal Chem 2002; 74:2416-22. [PMID: 12038769 DOI: 10.1021/ac020024j] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper describes synthetic micropore and nanotube membranes that mimic the function of a ligand-gated ion channel; that is, these membranes can be switched from an "off" state (no or low ion current through the membrane) to an "on" state (higher ion current) in response to the presence of a chemical stimulus. Ion channel mimics based on both microporous alumina and Au nanotube membranes were investigated. The off state was obtained by making the membranes hydrophobic by chemisorbing either a C18 silane (alumina membrane) or a C18 thiol (Au nanotube membrane). Water and electrolyte are forbidden from entering these very hydrophobic pores/nanotubes. The transition to the on state was induced by the partitioning of a hydrophobic ionic species (e.g., a drug or a surfactant) into the membrane. The membrane switches to the on state because at a sufficiently high concentration of this ionic analyte species, the pores/nanotubes flood with water and electrolyte. A pH-responsive membrane was also prepared by attaching a hydrophobic alkyl carboxylic acid silane to the alumina membrane.
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Affiliation(s)
- Erich D Steinle
- Department of Chemistry, University of Florida, Gainesville 32611-7200, USA
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23
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Photoinduced electron transfer across a gold supported octadecanethiol/phosphatidylcholine hybrid bilayer membrane mediated by C60 in different redox species solution. J Photochem Photobiol A Chem 2000. [DOI: 10.1016/s1010-6030(99)00238-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Nakaminami T, Ito S, Kuwabata S, Yoneyama H. A biomimetic phospholipid/alkanethiolate bilayer immobilizing uricase and an electron mediator on an Au electrode for amperometric determination of uric acid. Anal Chem 1999; 71:4278-83. [PMID: 10517148 DOI: 10.1021/ac981371p] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A biomimetic bilayer membrane immobilizing uricase (urate oxidase; EC 1.7.3.3) (UOx) and a redox agent of 1-methoxy-5-methylphenazinium (MMP) was fabricated on an Au electrode substrate with use of the Au substrate coated with a self-assembled monolayer of n-octanethiolate (OT/Au) and L-alpha-phosphatidylcholine beta-oleoyl-gamma-palmitoyl (PCOP). The preparation was carried out by successively immersing an Au electrode substrate in an ethanol solution of OT, an MMP aqueous solution, and a suspension of proteoliposome formed by PCOP containing UOx and MMP. The prepared electrode exhibited such fast steady amperometric responses to uric acid as to allow its determination within 20 s after injecting uric acid, indicating that UOx-catalyzed electrochemical oxidation of uric acid was accomplished with assistance of electron mediation by MMP between UOx and the Au substrate. An increase in the response currents with increasing concentration of uric acid was obtained in a concentration range of uric acid found in healthy human blood. Any interference in the current response that is caused by direct anodic oxidation of uric acid or ascorbic acid was not observed at the prepared sensor electrode because the densely packed bilayer effectively blocked the diffusion of these substrates toward the Au surface, making it possible to determine amperometrically uric acid at the electrode with high precision.
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Affiliation(s)
- T Nakaminami
- Department of Applied Chemistry, Faculty of Engineering, Osaka University, Japan
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25
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Diao P, Jiang D, Cui X, Gu D, Tong R, Zhong B. Unmodified supported thiol/lipid bilayers: studies of structural disorder and conducting mechanism by cyclic voltammetry and AC impedance. BIOELECTROCHEMISTRY AND BIOENERGETICS (LAUSANNE, SWITZERLAND) 1999; 48:469-75. [PMID: 10379570 DOI: 10.1016/s0302-4598(99)00038-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Supported thiol/lipid bilayer assembly, one of the most spectacular bilayer systems in recent years, has provided a good model to study biomembranes because of its high mechanical stability. In this work, the structural and conducting property of unmodified Au supported octadecanethiol/phosphatidylcholine bilayers were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The forming process of bilayer was monitored by capacitance plane plot. The normalized membrane capacitance of supported bilayer is 0.52 microF cm(-2). Kinetically controlled voltammograms determined by Butler-Volmer equation were obtained for both thiol monolayer and thiol/lipid bilayer in linear sweep voltammetry. Results of EIS experiment indicate that collapsed sites and pinhole defects exist in thiol monolayer and lipid monolayer, respectively. The difference between the values of experimental and theoretical standard electron transfer rate constant indicates that the conducting mechanism of Au supported thiol monolayer is electron tunneling at collapsed sites. The conducting mechanism of Au supported thiol/lipid bilayer is attributed as the following: the electroactive species could diffuse through pinholes in the lipid monolayer and reach collapsed sites in thiol monolayer, where electron transfer occurs via a tunneling process. The fractional coverage of the lipid monolayer measure by EIS experiments is about 0.98 or higher.
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Affiliation(s)
- P Diao
- Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan
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JING W, WANG E. Paint-Freeze Method to Form Self-Assembled Alkanethiol/Phospholipid Bilayers on Gold. ANAL SCI 1998. [DOI: 10.2116/analsci.14.117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Weiguo JING
- Laboratory of Electroanalytical Chemistry and National Analytical and Research Center of Electrochemistry and Spectroscopy, Changchun Instituteof Applied Chemistry, Chinese Academy of Sciences
| | - Erkang WANG
- Laboratory of Electroanalytical Chemistry and National Analytical and Research Center of Electrochemistry and Spectroscopy, Changchun Instituteof Applied Chemistry, Chinese Academy of Sciences
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Dong S, Li J. Self-assembled monolayers of thiols on gold electrodes for bioelectrochemistry and biosensors. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0302-4598(96)05172-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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