Vesicles with charged domains

Vesicles with charged domains

Author Vequi-Suplicy, Cíntia Cristina Google Scholar
Riske, Karin Amaral Autor UNIFESP Google Scholar
Knorr, Roland L. Google Scholar
Dimova, Rumiana Google Scholar
Institution Max Planck Inst Colloids & Interfaces
Universidade de São Paulo (USP)
Universidade Federal de São Paulo (UNIFESP)
Abstract This work summarizes results obtained on membranes composed of the ternary mixture dioleoylphosphatidylglycerol (DOPG), egg sphingomyelin (eSM) and cholesterol (Chol). the membrane phase state as a function of composition is characterized from data collected with fluorescence microscopy on giant unilamellar vesicles. the results suggest that the presence of the charged DOPG significantly decreases the composition region of coexistence of liquid ordered and liquid disordered phases as compared to that in the ternary mixture of dioleoylphosphatidycholine, sphingomyelin and cholesterol. the addition of calcium chloride to DOPG:eSM:Chol vesicles, and to a lesser extent the addition of sodium chloride, leads to the stabilization of the two-phase coexistence region, which is expressed in an increase in the miscibility temperature. On the other hand, addition of the chelating agent EDTA has the opposite effect, suggesting that impurities of divalent cations in preparations of giant vesicles contribute to the stabilization of charged domains. We also explore the behavior of these membranes in the presence of extruded unilamellar vesicles made of the positively charged lipid dioleoyltrimethylammoniumpropane (DOTAP). the latter can induce domain formation in DOPG:eSM:Chol vesicles with initial composition in the one-phase region. (C) 2010 Elsevier B.V. All rights reserved.
Keywords Giant vesicle
Confocal microscopy
Phase separation
Lipid raft
Membrane domain
Charged lipid
Egg sphingomyelin
Language English
Sponsor German Research Foundation (Deutsche Forschungsgemeinschaft)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Date 2010-07-01
Published in Biochimica Et Biophysica Acta-biomembranes. Amsterdam: Elsevier B.V., v. 1798, n. 7, p. 1338-1347, 2010.
ISSN 0005-2736 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 1338-1347
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000279365000008

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