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Measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers

For the past decade, droplet interface bilayers (DIBs) have had an increased prevalence in biomolecular and biophysical literature. However, much of the underlying physics of these platforms is poorly characterized. To further our understanding of these structures, lipid membrane tension on DIB memb...

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Autores principales: Barlow, Nathan E., Kusumaatmaja, Halim, Salehi-Reyhani, Ali, Brooks, Nick, Barter, Laura M. C., Flemming, Anthony J., Ces, Oscar
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6283991/
https://www.ncbi.nlm.nih.gov/pubmed/30464059
http://dx.doi.org/10.1098/rsif.2018.0610
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author Barlow, Nathan E.
Kusumaatmaja, Halim
Salehi-Reyhani, Ali
Brooks, Nick
Barter, Laura M. C.
Flemming, Anthony J.
Ces, Oscar
author_facet Barlow, Nathan E.
Kusumaatmaja, Halim
Salehi-Reyhani, Ali
Brooks, Nick
Barter, Laura M. C.
Flemming, Anthony J.
Ces, Oscar
author_sort Barlow, Nathan E.
collection PubMed
description For the past decade, droplet interface bilayers (DIBs) have had an increased prevalence in biomolecular and biophysical literature. However, much of the underlying physics of these platforms is poorly characterized. To further our understanding of these structures, lipid membrane tension on DIB membranes is measured by analysing the equilibrium shape of asymmetric DIBs. To this end, the morphology of DIBs is explored for the first time using confocal laser scanning fluorescence microscopy. The experimental results confirm that, in accordance with theory, the bilayer interface of a volume-asymmetric DIB is curved towards the smaller droplet and a lipid-asymmetric DIB is curved towards the droplet with the higher monolayer surface tension. Moreover, the DIB shape can be exploited to measure complex bilayer surface energies. In this study, the bilayer surface energy of DIBs composed of lipid mixtures of phosphatidylgylcerol (PG) and phosphatidylcholine are shown to increase linearly with PG concentrations up to 25%. The assumption that DIB bilayer area can be geometrically approximated as a spherical cap base is also tested, and it is discovered that the bilayer curvature is negligible for most practical symmetric or asymmetric DIB systems with respect to bilayer area.
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spelling pubmed-62839912018-12-17 Measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers Barlow, Nathan E. Kusumaatmaja, Halim Salehi-Reyhani, Ali Brooks, Nick Barter, Laura M. C. Flemming, Anthony J. Ces, Oscar J R Soc Interface Life Sciences–Chemistry interface For the past decade, droplet interface bilayers (DIBs) have had an increased prevalence in biomolecular and biophysical literature. However, much of the underlying physics of these platforms is poorly characterized. To further our understanding of these structures, lipid membrane tension on DIB membranes is measured by analysing the equilibrium shape of asymmetric DIBs. To this end, the morphology of DIBs is explored for the first time using confocal laser scanning fluorescence microscopy. The experimental results confirm that, in accordance with theory, the bilayer interface of a volume-asymmetric DIB is curved towards the smaller droplet and a lipid-asymmetric DIB is curved towards the droplet with the higher monolayer surface tension. Moreover, the DIB shape can be exploited to measure complex bilayer surface energies. In this study, the bilayer surface energy of DIBs composed of lipid mixtures of phosphatidylgylcerol (PG) and phosphatidylcholine are shown to increase linearly with PG concentrations up to 25%. The assumption that DIB bilayer area can be geometrically approximated as a spherical cap base is also tested, and it is discovered that the bilayer curvature is negligible for most practical symmetric or asymmetric DIB systems with respect to bilayer area. The Royal Society 2018-11 2018-11-21 /pmc/articles/PMC6283991/ /pubmed/30464059 http://dx.doi.org/10.1098/rsif.2018.0610 Text en © 2018 The Authors. http://creativecommons.org/licenses/by/4.0/ Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
spellingShingle Life Sciences–Chemistry interface
Barlow, Nathan E.
Kusumaatmaja, Halim
Salehi-Reyhani, Ali
Brooks, Nick
Barter, Laura M. C.
Flemming, Anthony J.
Ces, Oscar
Measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers
title Measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers
title_full Measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers
title_fullStr Measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers
title_full_unstemmed Measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers
title_short Measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers
title_sort measuring bilayer surface energy and curvature in asymmetric droplet interface bilayers
topic Life Sciences–Chemistry interface
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6283991/
https://www.ncbi.nlm.nih.gov/pubmed/30464059
http://dx.doi.org/10.1098/rsif.2018.0610
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