Asymmetric bilayers mimicking membrane rafts prepared by lipid exchange: nanoscale characterization using AFM-Force spectroscopy

Sphingolipids-enriched rafts domains are proposed to occur in plasma membranes and to mediate important cellular functions. Notwithstanding, the asymmetric transbilayer distribution of phospholipids that exists in the membrane confers the two leaflets different potentials to form lateral domains as...

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Autores principales: Vázquez, Romina Florencia, Ovalle García, Erasmo, Antillón, Armando, Ortega Blakec, Iván, Bakás, Laura Susana, Muñoz Garay, Carlos, Maté, Sabina María
Formato: Articulo
Lenguaje:Inglés
Publicado: 2021
Materias:
Bioquímica
Lipid asymmetry
Sphingomyelin
Lipid domains
Supported lipid bilayers
Atomic force microscopy
Force spectroscopy
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/159784
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-159784
record_format dspace
spelling I19-R120-10915-1597842023-11-03T20:06:44Z http://sedici.unlp.edu.ar/handle/10915/159784 Asymmetric bilayers mimicking membrane rafts prepared by lipid exchange: nanoscale characterization using AFM-Force spectroscopy Vázquez, Romina Florencia Ovalle García, Erasmo Antillón, Armando Ortega Blakec, Iván Bakás, Laura Susana Muñoz Garay, Carlos Maté, Sabina María 2021 2023-11-03T18:46:48Z en Bioquímica Lipid asymmetry Sphingomyelin Lipid domains Supported lipid bilayers Atomic force microscopy Force spectroscopy Sphingolipids-enriched rafts domains are proposed to occur in plasma membranes and to mediate important cellular functions. Notwithstanding, the asymmetric transbilayer distribution of phospholipids that exists in the membrane confers the two leaflets different potentials to form lateral domains as next to no sphingolipids are present in the inner leaflet. How the physical properties of one leaflet can influence the properties of the other and its importance on signal transduction across the membrane are questions still unresolved. In this work, we combined AFM imaging and Force spectroscopy measurements to assess domain formation and to study the nanomechanical properties of asymmetric supported lipid bilayers (SLBs) mimicking membrane rafts. Asymmetric SLBs were formed by incorporating N-palmitoyl-sphingomyelin (16:0SM) into the outer leaflet of preformed 1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC)/Cholesterol SLBs through methyl-β-cyclodextrin– mediated lipid exchange. Lipid domains were detected after incorporation of 16:0SM though their phase state varied from gel to liquid ordered (Lo) phase if the procedure was performed at 24 or 37 °C, respectively. When comparing symmetric and asymmetric Lo domains, differences in size and morphology were observed, with asymmetric domains being smaller and more interconnected. Both types of Lo domains showed similar mechanical stability in terms of rupture forces and Young's moduli. Notably, force curves in asymmetric domains presented two rupture events that could be attributed to the sequential rupture of a liquid disordered (Ld) and a Lo phase. Interleaflet coupling in asymmetric Lo domains could also be inferred from those measurements. The experimental approach outlined here would significantly enhance the applicability of membrane models. Instituto de Investigaciones Bioquímicas de La Plata Centro de Investigación de Proteínas Vegetales Articulo Articulo http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) application/pdf
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Bioquímica
Lipid asymmetry
Sphingomyelin
Lipid domains
Supported lipid bilayers
Atomic force microscopy
Force spectroscopy
spellingShingle Bioquímica
Lipid asymmetry
Sphingomyelin
Lipid domains
Supported lipid bilayers
Atomic force microscopy
Force spectroscopy
Vázquez, Romina Florencia
Ovalle García, Erasmo
Antillón, Armando
Ortega Blakec, Iván
Bakás, Laura Susana
Muñoz Garay, Carlos
Maté, Sabina María
Asymmetric bilayers mimicking membrane rafts prepared by lipid exchange: nanoscale characterization using AFM-Force spectroscopy
topic_facet Bioquímica
Lipid asymmetry
Sphingomyelin
Lipid domains
Supported lipid bilayers
Atomic force microscopy
Force spectroscopy
description Sphingolipids-enriched rafts domains are proposed to occur in plasma membranes and to mediate important cellular functions. Notwithstanding, the asymmetric transbilayer distribution of phospholipids that exists in the membrane confers the two leaflets different potentials to form lateral domains as next to no sphingolipids are present in the inner leaflet. How the physical properties of one leaflet can influence the properties of the other and its importance on signal transduction across the membrane are questions still unresolved. In this work, we combined AFM imaging and Force spectroscopy measurements to assess domain formation and to study the nanomechanical properties of asymmetric supported lipid bilayers (SLBs) mimicking membrane rafts. Asymmetric SLBs were formed by incorporating N-palmitoyl-sphingomyelin (16:0SM) into the outer leaflet of preformed 1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC)/Cholesterol SLBs through methyl-β-cyclodextrin– mediated lipid exchange. Lipid domains were detected after incorporation of 16:0SM though their phase state varied from gel to liquid ordered (Lo) phase if the procedure was performed at 24 or 37 °C, respectively. When comparing symmetric and asymmetric Lo domains, differences in size and morphology were observed, with asymmetric domains being smaller and more interconnected. Both types of Lo domains showed similar mechanical stability in terms of rupture forces and Young's moduli. Notably, force curves in asymmetric domains presented two rupture events that could be attributed to the sequential rupture of a liquid disordered (Ld) and a Lo phase. Interleaflet coupling in asymmetric Lo domains could also be inferred from those measurements. The experimental approach outlined here would significantly enhance the applicability of membrane models.
format Articulo
Articulo
author Vázquez, Romina Florencia
Ovalle García, Erasmo
Antillón, Armando
Ortega Blakec, Iván
Bakás, Laura Susana
Muñoz Garay, Carlos
Maté, Sabina María
author_facet Vázquez, Romina Florencia
Ovalle García, Erasmo
Antillón, Armando
Ortega Blakec, Iván
Bakás, Laura Susana
Muñoz Garay, Carlos
Maté, Sabina María
author_sort Vázquez, Romina Florencia
title Asymmetric bilayers mimicking membrane rafts prepared by lipid exchange: nanoscale characterization using AFM-Force spectroscopy
title_short Asymmetric bilayers mimicking membrane rafts prepared by lipid exchange: nanoscale characterization using AFM-Force spectroscopy
title_full Asymmetric bilayers mimicking membrane rafts prepared by lipid exchange: nanoscale characterization using AFM-Force spectroscopy
title_fullStr Asymmetric bilayers mimicking membrane rafts prepared by lipid exchange: nanoscale characterization using AFM-Force spectroscopy
title_full_unstemmed Asymmetric bilayers mimicking membrane rafts prepared by lipid exchange: nanoscale characterization using AFM-Force spectroscopy
title_sort asymmetric bilayers mimicking membrane rafts prepared by lipid exchange: nanoscale characterization using afm-force spectroscopy
publishDate 2021
url http://sedici.unlp.edu.ar/handle/10915/159784
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