1
|
Su Z, Goodall B, Leitch JJ, Lipkowski J. Ion transport mechanism in gramicidin A channels formed in floating bilayer lipid membranes supported on gold electrodes. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.137892] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
2
|
Interaction of cholesterol with artificial bilayer lipid membrane system and development of an electrochemical sensor. ARAB J CHEM 2020. [DOI: 10.1016/j.arabjc.2017.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
3
|
|
4
|
Skalová Š, Vyskočil V, Barek J, Navrátil T. Model Biological Membranes and Possibilities of Application of Electrochemical Impedance Spectroscopy for their Characterization. ELECTROANAL 2017. [DOI: 10.1002/elan.201700649] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Štěpánka Skalová
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences; Dolejškova 3 182 23 Prague 8 Czech Republic
- Charles University; Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry; Hlavova 2030/8 128 43 Prague 2 Czech Republic
| | - Vlastimil Vyskočil
- Charles University; Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry; Hlavova 2030/8 128 43 Prague 2 Czech Republic
| | - Jiří Barek
- Charles University; Faculty of Science, Department of Analytical Chemistry, UNESCO Laboratory of Environmental Electrochemistry; Hlavova 2030/8 128 43 Prague 2 Czech Republic
| | - Tomáš Navrátil
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences; Dolejškova 3 182 23 Prague 8 Czech Republic
| |
Collapse
|
5
|
Rameshkumar S, Kumaravel M. CHANGES IN THE ELECTRICAL PROPERTIES OF AGARGEL SUPPORTED BILAYER LIPID MEMBRANE BROUGHT ABOUT BY MIDAZOLAM. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.05.180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
6
|
Gramicidin A ion channel formation in model phospholipid bilayers tethered to gold (111) electrode surfaces. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.05.059] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
7
|
Diamanti E, Gregurec D, Rodríguez-Presa MJ, Gervasi CA, Azzaroni O, Moya SE. High Resistivity Lipid Bilayers Assembled on Polyelectrolyte Multilayer Cushions: An Impedance Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:6263-6271. [PMID: 27267089 DOI: 10.1021/acs.langmuir.6b01191] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Supported membranes on top of polymer cushions are interesting models of biomembranes as cell membranes are supported on a polymer network of proteins and sugars. In this work lipid vesicles formed by a mixture of 30% 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 70% 1,2-dioleoyl-sn-glycero-3-phospho-l-serine (DOPS) are assembled on top of a polyelectrolyte multilayer (PEM) cushion of poly(allylamine hydrochloride) (PAH) and poly(styrene sodium sulfonate) (PSS). The assembly results in the formation of a bilayer on top of the PEM as proven by means of the quartz crystal microbalance with dissipation technique (QCM-D) and by cryo-transmission electron microscopy (cryo-TEM). The electrical properties of the bilayer are studied by electrochemical impedance spectroscopy (EIS). The bilayer supported on the PEMs shows a high resistance, on the order of 10(7) Ω cm(2), which is indicative of a continuous, dense bilayer. Such resistance is comparable with the resistance of black lipid membranes. This is the first time that such values are obtained for lipid bilayers supported on PEMs. The assembly of polyelectrolytes on top of a lipid bilayer decreases the resistance of the bilayer up to 2 orders of magnitude. The assembly of the polyelectrolytes on the lipids induces defects or pores in the bilayer which in turn prompts a decrease in the measured resistance.
Collapse
Affiliation(s)
- Eleftheria Diamanti
- Soft Matter Nanotechnology Group, CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastián, Guipúzcoa, Spain
| | - Danijela Gregurec
- Soft Matter Nanotechnology Group, CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastián, Guipúzcoa, Spain
| | - María José Rodríguez-Presa
- Instituto de Investigaciones, Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, CONICET , Sucursal 4-C.C.16, 1900 La Plata, Argentina
| | - Claudio A Gervasi
- Instituto de Investigaciones, Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, CONICET , Sucursal 4-C.C.16, 1900 La Plata, Argentina
- Area Electroquímica, Facultad de Ingeniería, Universidad Nacional de La Plata , calle 1 y 47, 1900 La Plata, Argentina
| | - Omar Azzaroni
- Instituto de Investigaciones, Fisicoquímicas Teóricas y Aplicadas (INIFTA), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de la Plata, CONICET , Sucursal 4-C.C.16, 1900 La Plata, Argentina
| | - Sergio E Moya
- Soft Matter Nanotechnology Group, CIC biomaGUNE, Paseo Miramón 182 C, 20009 San Sebastián, Guipúzcoa, Spain
| |
Collapse
|
8
|
Mallaiya K, Rameshkumar S, Subramanian S, Ramalingam S, Ramachandran T. Electrochemical impedance studies on the interaction of midazolam with planar lipid bilayer. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.06.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
9
|
Naumowicz M, Figaszewski ZA. Pore formation in lipid bilayer membranes made of phosphatidylcholine and cholesterol followed by means of constant current. Cell Biochem Biophys 2013; 66:109-19. [PMID: 23104105 PMCID: PMC3627032 DOI: 10.1007/s12013-012-9459-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This paper describes the application of chronopotentiometry to lipid bilayer research. The experiments were performed on bilayer lipid membranes composed of phosphatidylcholine and cholesterol and formed using the painting technique. Chronopotentiometric (U = f(t)) measurements were used to determine the membrane capacitance, resistance, and breakdown voltage as well as pore conductance and diameter.
Collapse
Affiliation(s)
- Monika Naumowicz
- Institute of Chemistry, University of Bialystok, Al. J. Pilsudskiego 11/4, 15-443, Bialystok, Poland.
| | | |
Collapse
|
10
|
Selvaraj S, Mohan A, Narayanan S, Sethuraman S, Krishnan UM. Dose-Dependent Interaction of trans-Resveratrol with Biomembranes: Effects on Antioxidant Property. J Med Chem 2013; 56:970-81. [DOI: 10.1021/jm3014579] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Stalin Selvaraj
- Centre for Nanotechnology and
Advanced Biomaterials (CeNTAB), School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India
| | - Aarti Mohan
- Centre for Nanotechnology and
Advanced Biomaterials (CeNTAB), School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India
| | - Shridhar Narayanan
- Orchid Chemicals and Pharmaceuticals Ltd., Sozhiganallur, Chennai 600
119, Tamil Nadu, India
| | - Swaminathan Sethuraman
- Centre for Nanotechnology and
Advanced Biomaterials (CeNTAB), School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India
| | - Uma Maheswari Krishnan
- Centre for Nanotechnology and
Advanced Biomaterials (CeNTAB), School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India
| |
Collapse
|
11
|
Campos R, Kataky R. Electron Transport in Supported and Tethered Lipid Bilayers Modified with Bioelectroactive Molecules. J Phys Chem B 2012; 116:3909-17. [DOI: 10.1021/jp209772u] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rui Campos
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Ritu Kataky
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| |
Collapse
|
12
|
Zhang X, Tanner P, Graff A, Palivan CG, Meier W. Mimicking the cell membrane with block copolymer membranes. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/pola.26000] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
13
|
Impedance analysis of complex formation equilibria in phosphatidylcholine bilayers containing decanoic acid or decylamine. Cell Biochem Biophys 2011; 61:145-55. [PMID: 21340532 PMCID: PMC3153661 DOI: 10.1007/s12013-011-9171-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Bilayer lipid membranes composed of phosphatidylcholine and decanoic acid or phosphatidylcholine and decylamine were investigated using electrochemical impedance spectroscopy. Interaction between membrane components causes significant deviations from the additivity rule. Area, capacitance, and stability constant values for the complexes were calculated based on the model assuming 1:1 stoichiometry, and the model was validated by comparison of these values to experimental results. We established that phosphatidylcholine and decylamine form highly stable 1:1 complexes. In the case of decanoic acid-modified phosphatidylcholine membranes, complexes with stoichiometries other than 1:1 should be taken into consideration.
Collapse
|
14
|
Naumowicz M, Petelska AD, Figaszewski ZA. Chronopotentiometric studies of phosphatidylcholine bilayers modified by ergosterol. Steroids 2011; 76:967-73. [PMID: 21641920 DOI: 10.1016/j.steroids.2011.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/19/2011] [Accepted: 05/19/2011] [Indexed: 10/18/2022]
Abstract
We have monitored the effect of ergosterol on electrical capacitance and electrical resistance of the phosphatidylcholine bilayer membranes using chronopotentiometry method. The chronopotentiometric characteristic of the bilayers depends on constant-current flow through the membranes. For low current values, no electroporation takes place and the membrane voltage rises exponentially to a constant value described by the Ohm's law. Based on these kinds of chronopotentiometric curves, a method of the membrane capacitance and the membrane resistance calculations is presented.
Collapse
Affiliation(s)
- Monika Naumowicz
- Institute of Chemistry, University of Bialystok, Al. J. Pilsudskiego 11/4, 15-443 Bialystok, Poland.
| | | | | |
Collapse
|
15
|
Chronopotentiometric technique as a method for electrical characterization of bilayer lipid membranes. J Membr Biol 2011; 240:47-53. [PMID: 21249348 DOI: 10.1007/s00232-011-9341-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 01/02/2011] [Indexed: 10/18/2022]
Abstract
The basic electrical parameters of bilayer lipid membranes are capacitance and resistance. This article describes the application of chronopotentiometry to the research of lipid bilayers. Membranes were made from egg yolk phosphatidylcholine. The chronopotentiometric characteristic of the membranes depends on the current value. For low current values, no electroporation takes place and the voltage rises exponentially to a constant value. Based on these kinds of chronopotentiometric curves, a method of the membrane capacitance and the membrane resistance calculations are presented.
Collapse
|
16
|
Effect of acetylsalicylic acid on the current–voltage characteristics of planar lipid membranes. Biophys Chem 2009; 142:27-33. [DOI: 10.1016/j.bpc.2009.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 02/27/2009] [Accepted: 03/01/2009] [Indexed: 10/21/2022]
|
17
|
Naumowicz M, Figaszewski ZA. Impedance spectroscopic investigation of the bilayer lipid membranes formed from the phosphatidylserine-ceramide mixture. J Membr Biol 2009; 227:67-75. [PMID: 19122973 DOI: 10.1007/s00232-008-9144-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Accepted: 11/22/2008] [Indexed: 10/21/2022]
Abstract
Electrochemical impedance spectroscopy was used for the study of two-component lipid membranes. Phosphatidylserine and ceramide were to be investigated because they play an important biochemical role in cell membranes. The research on biolipid interaction was focused on a quantitative description of processes that take part in a bilayer. Assumed models of interaction between amphiphilic molecules and the equilibria that take place there were described by mathematical equations for the studied system. The possibility of complex formation for a two-component system forming bilayers was assumed, which could explain the deviation from the additivity rule. The molecular area and the equilibrium constant of the complex were determined.
Collapse
Affiliation(s)
- Monika Naumowicz
- Institute of Chemistry, University of Bialystok, Al. J. Pilsudskiego 11/4, 15-443, Bialystok, Poland
| | | |
Collapse
|
18
|
Impedance spectroscopic investigation of the interactions between phosphatidylethanolamine and α-tocopherol in bilayer membranes. Electrochim Acta 2009. [DOI: 10.1016/j.electacta.2008.08.051] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
19
|
New Approaches to Lipid Bilayer Fabrication: Microfluidic Solvent Extraction and Hydrogel Encapsulation. ACTA ACUST UNITED AC 2006. [DOI: 10.4028/www.scientific.net/ast.53.22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Membrane channel proteins play crucial roles in governing the transport of material and energy across every cellular membrane. Accordingly, they are the subjects of interest for science and medicine as well as major targets of drug discovery efforts. Recent work has also shown their potential as highly rapid and sensitive single molecule sensors. However, techniques conventionally used to measure the electrical transport through these proteins can be problematic to form and are extremely fragile, limiting the range and scope of possible studies. We have developed two new technologies which alleviate these shortcomings: in situ encapsulation of lipid membranes in hydrogels and automated microfluidic formation. The hydrogel encapsulated membranes are mechanically robust and long-lived as a result of the intimate contact between the hydrogel and the membrane, enabling measurements of single channel currents for a week or longer. The automated microfluidic formation apparatus enables the creation and manipulation of lipid membranes and the incorporation and measurement of channel proteins in these membranes through an entirely computer controlled process. We are working to apply these technologies toward DNA sequencing, drug discovery, and single molecule biophysics.
Collapse
|
20
|
Neville F, Gidalevitz D, Kale G, Nelson A. Electrochemical screening of anti-microbial peptide LL-37 interaction with phospholipids. Bioelectrochemistry 2006; 70:205-13. [PMID: 16949887 DOI: 10.1016/j.bioelechem.2006.07.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 05/18/2006] [Accepted: 07/07/2006] [Indexed: 11/25/2022]
Abstract
LL-37 is an alpha-helical antimicrobial peptide of human origin. It is a 37 residue cathelicidin peptide. This paper explores the use of electrochemical methods to investigate the interaction of LL-37 with phospholipid and lipid A monolayers on a mercury drop electrode. Experiments were carried out in Dulbecco's phosphate buffered saline at pH approximately 7.6. The capacity-potential curves of the coated electrode in the presence and absence of LL-37 were measured using out-of-phase ac voltammetry. The frequency dependence of the complex impedance of the coated electrode in the presence and absence of LL-37 was estimated at -0.4 V versus Ag/AgCl 3.5 mol dm(-3) KCl. The monolayer permeability to ions was studied by following the reduction of Tl(I) to Tl(Hg) at the coated electrode. LL-37 shows no significant interaction with DOPC. However, LL-37 shows a small interaction with DOPG and lipid A within a DOPC monolayer where the monolayer permeability is marginally increased and the zero frequency capacitance (ZFC) is marginally decreased in both cases. LL-37 shows a significant interaction with a lipid A monolayer thereby decreasing the ZFC by 30%. The results concur with the known membrane active properties of LL-37 and establish this electrochemical approach as a key technique for screening peptides.
Collapse
Affiliation(s)
- Frances Neville
- Institute for Materials Research, School of Process, Environmental and Materials Engineering, University of Leeds, LS2 9JT, UK
| | | | | | | |
Collapse
|
21
|
Impedance analysis of a phosphatidylcholine–phosphatidylethanolamine system in bilayer lipid membranes. Electrochim Acta 2006. [DOI: 10.1016/j.electacta.2006.03.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
22
|
Chapter 5 Physicochemical Insights into Equilibria in Bilayer Lipid Membranes. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/s1554-4516(05)03005-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
23
|
Abstract
We have encapsulated free-standing planar lipid membranes in a polymer hydrogel via in situ photopolymerization. These encapsulated membranes were measured to last at least 5 days and provided a stable environment for single-molecule measurements of incorporated alpha-hemolysin channel proteins. The translocation of single-stranded DNA through alpha-hemolysin incorporated into these encapsulated membranes is slowed over 100 times relative to that of the gel-free state. These stabilized membranes, therefore, have application to the single-molecule analysis of DNA as well as broader application to biomolecular sensors, membrane protein biophysical studies, and drug discovery.
Collapse
Affiliation(s)
- Tae-Joon Jeon
- Department of Bioengineering, University of California-Los Angeles, Los Angeles, CA 90095, USA
| | | | | |
Collapse
|
24
|
Naumowicz M, Kotynska J, Petelska A, Figaszewski Z. Impedance analysis of phosphatidylcholine membranes modified with valinomycin. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2005; 35:239-46. [PMID: 16283290 DOI: 10.1007/s00249-005-0030-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Revised: 10/10/2005] [Accepted: 10/18/2005] [Indexed: 10/25/2022]
Abstract
The effect of the ion carrier valinomycin on the electrochemical features of the phosphatidylcholine membrane was investigated by electrochemical impedance spectroscopy. Phosphatidylcholine and valinomycin were chosen for the study because they fulfil essential functions in lively organisms. The experimental impedance values obtained in the presence of different amounts of carrier, studied with several potassium ion concentrations, were used for the research ability of valinomycin to form a 1:1 potassium ion complex on the lipid bilayer/electrolyte solution interface. Based on derived mathematical equations, the heterogeneous equilibrium constant (K (h)), association rate constant of the complex (k (R)) and dissociation rate constant of the complex (k (D)) were calculated. The result of the investigation is the proposal of a new method for the determination of the parameters used to describe the chemical reaction at the interface between a carrier molecule from the membrane and a monovalent ion from the aqueous phase.
Collapse
Affiliation(s)
- Monika Naumowicz
- Institute of Chemistry, University of Bialystok, Al. J. Pilsudskiego 11/4, 15-443 Bialystok, Poland
| | | | | | | |
Collapse
|
25
|
Naumowicz M, Figaszewski ZA. Impedance analysis of lipid domains in phosphatidylcholine bilayer membranes containing ergosterol. Biophys J 2005; 89:3174-82. [PMID: 16126831 PMCID: PMC1366813 DOI: 10.1529/biophysj.105.063446] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Accepted: 07/07/2005] [Indexed: 11/18/2022] Open
Abstract
The effect of ergosterol on the electrochemical features of the phosphatidylcholine bilayer membrane was investigated by impedance spectroscopy. The experimental impedance values obtained in the presence of different amounts of ergosterol showed evidence of domain structures within the bilayer containing < 0.06 molar fraction of ergosterol. Based on derived mathematical equations, the surface area of phospholipid/ergosterol domain was calculated; it amounts to 262 A(2). This value is consistent, taking into consideration the presented measurements as well as ordering and condensation effects of ergosterol, with a stoichiometry of such a domain equal to 3:1. The result of the investigation is the proposal of a new and simple method for the determination of the surface area and description stoichiometry of domains formed in any two-component system.
Collapse
Affiliation(s)
- Monika Naumowicz
- Institute of Chemistry, University of Bialystok, Bialystok, Poland
| | | |
Collapse
|
26
|
Naumowicz M, Figaszewski ZA. Impedance Analysis of Phosphatidylcholine/α-Tocopherol System in Bilayer Lipid Membranes. J Membr Biol 2005; 205:29-36. [PMID: 16245040 DOI: 10.1007/s00232-005-0760-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2004] [Revised: 02/24/2005] [Indexed: 11/30/2022]
Abstract
The effect of alpha-tocopherol on the electrochemical features of the phosphatidylcholine membrane was investigated by impedance spectroscopy. Phosphatidylcholine and alpha-tocopherol were chosen for the study because they are present in biological membranes and they fulfill essential functions in living organisms. The experimental impedance values obtained in the presence of different amounts of alpha-tocopherol showed evidence of domain structures within the bilayer containing less than 0.048 molar fraction of alpha-tocopherol. Based on derived mathematical equations, the surface area of phospholipid/alpha-tocopherol domain was calculated; it amounts to 832 A(2). This value is consistent, taking into consideration ordering and condensation effects of alpha-tocopherol, with the acknowledged, well documented, stoichiometry of such a domain of 10:1. The result of the investigation is the proposal of a new method for the determination of the surface area and description of the stoichiometry of domains formed in any two-component system.
Collapse
Affiliation(s)
- M Naumowicz
- Institute of Chemistry, University of Bialystok, Al. J. Pilsudskiego 11/4, 15-443 Bialystok, Poland
| | | |
Collapse
|
27
|
Naumowicz M, Petelska AD, Figaszewski ZA. Impedance analysis of phosphatidylcholine–cholesterol system in bilayer lipid membranes. Electrochim Acta 2005. [DOI: 10.1016/j.electacta.2004.09.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
28
|
Petelska AD, Naumowicz M, Figaszewski ZA. The effect of interaction between K+ ions and gramicidin D on the lecithin membrane interfacial tension. Bioelectrochemistry 2005; 65:143-8. [PMID: 15713565 DOI: 10.1016/j.bioelechem.2004.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2004] [Revised: 08/12/2004] [Accepted: 10/04/2004] [Indexed: 11/17/2022]
Abstract
The effect of the presence of gramicidin D in a lecithin membrane on its interfacial tension has been studied. The studies have been carried out at various forming solution compositions and at various potassium ion concentrations in the electrolyte solution. Potassium chloride was used as the electrolyte. The complex was formed between the gramicidin molecule and K(+) ion. The following parameters describing the complex were determined: the surface area occupied by GK(+) complex (A(GK(+))), the interfacial tension of the GK(+) membrane complex (gamma(GK+)), and the stability constant of the gramicidin-K(+) complex (K). These values are 156 A(2), 1.89 mN m(-1) and 0.033 m(3) mol(-1), respectively.
Collapse
Affiliation(s)
- Aneta D Petelska
- Institute of Chemistry, University of Bialystok, Al. J. Pilsudskiego 11/4, 15-443 Bialystok, Poland
| | | | | |
Collapse
|