Structure and properties of tethered bilayer lipid membranes with unsaturated anchor molecules
| Autor: | Frank Heinrich, Mathias Lösche, Gediminas Niaura, Rima Budvytyte, Mindaugas Mickevicius, Gintaras Valincius, David J. Vanderah, Prabhanshu Shekhar, Haw-Zan Goh, Siddharth Shenoy, Hilary Chapman, Vladislava Voiciuk |
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| Rok vydání: | 2013 |
| Předmět: |
chemistry.chemical_classification
Models Molecular Double bond Molecular Structure Lipid Bilayers Analytical chemistry Infrared spectroscopy FOS: Physical sciences Surfaces and Interfaces 20399 Classical Physics not elsewhere classified Condensed Matter Physics Mole fraction Lipids Article Dielectric spectroscopy Contact angle Crystallography chemistry Monolayer Electrochemistry General Materials Science Lipid bilayer Spectroscopy Alkyl Mercaptoethanol |
| Zdroj: | Langmuir : the ACS journal of surfaces and colloids. 29(27) |
| ISSN: | 1520-5827 |
| Popis: | The self-assembled monolayers (SAMs) of new lipidic anchor molecule HC18 [Z-20-(Z-octadec-9-enyloxy)-3,6,9,12,15,18,22-heptaoxatetracont-31-ene-1-thiol] and mixed HC18/β-mercaptoethanol (βME) SAMs were studied by spectroscopic ellipsometry, contact angle measurements, reflection-absorption infrared spectroscopy, and electrochemical impedance spectroscopy (EIS) and were evaluated in tethered bilayer lipid membranes (tBLMs). Our data indicate that HC18, containing a double bond in the alkyl segments, forms highly disordered SAMs up to anchor/βME molar fraction ratios of 80/20 and result in tBLMs that exhibit higher lipid diffusion coefficients relative to those of previous anchor compounds with saturated alkyl chains, as determined by fluorescence correlation spectroscopy. EIS data shows the HC18 tBLMs, completed by rapid solvent exchange or vesicle fusion, form more easily than with saturated lipidic anchors, exhibit excellent electrical insulating properties indicating low defect densities, and readily incorporate the pore-forming toxin α-hemolysin. Neutron reflectivity measurements on HC18 tBLMs confirm the formation of complete tBLMs, even at low tether compositions and high ionic lipid compositions. Our data indicate that HC18 results in tBLMs with improved physical properties for the incorporation of integral membrane proteins (IMPs) and that 80% HC18 tBLMs appear to be optimal for practical applications such as biosensors where high electrical insulation and IMP/peptide reconstitution are imperative. |
| Databáze: | OpenAIRE |
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