Fast Formation of Low-Defect-Density Tethered Bilayers by Fusion of Multilamellar Vesicles

Published

January 10, 2017

Author(s)

Tadas Ragaliauskas, Mindaugas Mickevicius, Bozena Rakovska, Tadas Penkauskas, Frank Heinrich, Gintaras Valincius

Abstract

Multilamelar vesicles fuse to molecular-anchor-grafted surfaces yielding low defect density, tethered bilayer membranes. Continuous bilayers are formed within 10 min, while the electrically insulating bilayers with less than 0,1 υmu-1} defect density can be accomplished within 60 min. Surface plasmon resonance spectroscopy indicates that an amount of lipid material transferred from vesicles to a surface is inversely proportional to the density of an anchor, while the total amount of lipid that includes tethered and transferred lipid remains constant within 5% standard error. This attest for the possibility of the formation of intact bilayers independently of the density of tethering agent. Neutron reflectometry revealed the atomic level structural details tethered bilayer. The total thickness of the hydrophobic slab of the construct was found to be 3,2 nm. Accordingly to the neutron reflectometry, the molar fraction of cholesterol in non-tethered lipid content is essentially the same as the molar fraction of cholesterol in multilamelar liposomes. NR also, indicate the formation of overlayer, with effective thickness of 1,9 nm. These overlayers may be easily removed by a single rinse of the tethered construct with 30% ethanol solution. Fast assembly and low residual defect density achievable within an hour of fusion makes our tethered bilayer methodology an attractive platform for bio sensing of membrane damaging agents, such as pore forming toxins.

Citation

Biochimica Et Biophysica Acta

Volume

1859

Issue

5

Pub Type

Journals

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Keywords

tethered lipid bilayer membranes, vesicle fusion, electrochemical impedance spectroscopy, neutron reflectometry

Citation

Ragaliauskas, T. , Mickevicius, M. , Rakovska, B. , Penkauskas, T. , Heinrich, F. and Valincius, G. (2017), Fast Formation of Low-Defect-Density Tethered Bilayers by Fusion of Multilamellar Vesicles, Biochimica Et Biophysica Acta, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=918753 (Accessed October 4, 2024)