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Effects of surfactin on membrane models displaying lipid phase separation

Deleu, Magali; Lorent, Joseph; Lins, Laurence; Brasseur, Robert; Braun, Nathalie; El Kirat, Karim; Nylander, Tommy LU ; Dufrene, Yves F. and Mingeot-Leclercq, Marie-Paule (2013) In Biochimica et Biophysica Acta - Biomembranes 1828(2). p.801-815
Abstract
Surfactin, a bacterial amphiphilic lipopeptide is attracting more and more attention in view of its bioactive properties which are in relation with its ability to interact with lipids of biological membranes. In this work, we investigated the effect of surfactin on membrane structure using model of membranes, vesicles as well as supported bilayers, presenting coexistence of fluid-disordered (DOPC) and gel (DPPC) phases. A range of complementary methods was used including AFM, ellipsometry, dynamic light scattering, fluorescence measurements of Laurdan, DPH, calcein release, and octadecylrhodamine B dequenching. Our findings demonstrated that surfactin concentration is critical for its effect on the membrane. The results suggest that the... (More)
Surfactin, a bacterial amphiphilic lipopeptide is attracting more and more attention in view of its bioactive properties which are in relation with its ability to interact with lipids of biological membranes. In this work, we investigated the effect of surfactin on membrane structure using model of membranes, vesicles as well as supported bilayers, presenting coexistence of fluid-disordered (DOPC) and gel (DPPC) phases. A range of complementary methods was used including AFM, ellipsometry, dynamic light scattering, fluorescence measurements of Laurdan, DPH, calcein release, and octadecylrhodamine B dequenching. Our findings demonstrated that surfactin concentration is critical for its effect on the membrane. The results suggest that the presence of rigid domains can play an essential role in the first step of surfactin insertion and that surfactin interacts both with the membrane polar heads and the acyl chain region. A mechanism for the surfactin lipid membrane interaction, consisting of three sequential structural and morphological changes, is proposed. At concentrations below the CMC, surfactin inserted at the boundary between gel and fluid lipid domains, inhibited phase separation and stiffened the bilayer without global morphological change of liposomes. At concentrations close to CMC, surfactin solubilized the fluid phospholipid phase and increased order in the remainder of the lipid bilayer. At higher surfactin concentrations, both the fluid and the rigid bilayer structures were dissolved into mixed micelles and other structures presenting a wide size distribution. (C) 2012 Elsevier B.V. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Surfactin, Membrane interaction, Phase coexistence, Laurdan and DPH, fluorescence, Ellipsometry, AFM
in
Biochimica et Biophysica Acta - Biomembranes
volume
1828
issue
2
pages
801 - 815
publisher
Elsevier
external identifiers
  • wos:000315004600070
  • scopus:84870666552
ISSN
0005-2736
DOI
10.1016/j.bbamem.2012.11.007
language
English
LU publication?
yes
id
3d32396b-3023-49b5-9f44-e6677f7283c1 (old id 3749458)
date added to LUP
2013-05-21 08:32:19
date last changed
2019-06-25 01:56:08
@article{3d32396b-3023-49b5-9f44-e6677f7283c1,
  abstract     = {Surfactin, a bacterial amphiphilic lipopeptide is attracting more and more attention in view of its bioactive properties which are in relation with its ability to interact with lipids of biological membranes. In this work, we investigated the effect of surfactin on membrane structure using model of membranes, vesicles as well as supported bilayers, presenting coexistence of fluid-disordered (DOPC) and gel (DPPC) phases. A range of complementary methods was used including AFM, ellipsometry, dynamic light scattering, fluorescence measurements of Laurdan, DPH, calcein release, and octadecylrhodamine B dequenching. Our findings demonstrated that surfactin concentration is critical for its effect on the membrane. The results suggest that the presence of rigid domains can play an essential role in the first step of surfactin insertion and that surfactin interacts both with the membrane polar heads and the acyl chain region. A mechanism for the surfactin lipid membrane interaction, consisting of three sequential structural and morphological changes, is proposed. At concentrations below the CMC, surfactin inserted at the boundary between gel and fluid lipid domains, inhibited phase separation and stiffened the bilayer without global morphological change of liposomes. At concentrations close to CMC, surfactin solubilized the fluid phospholipid phase and increased order in the remainder of the lipid bilayer. At higher surfactin concentrations, both the fluid and the rigid bilayer structures were dissolved into mixed micelles and other structures presenting a wide size distribution. (C) 2012 Elsevier B.V. All rights reserved.},
  author       = {Deleu, Magali and Lorent, Joseph and Lins, Laurence and Brasseur, Robert and Braun, Nathalie and El Kirat, Karim and Nylander, Tommy and Dufrene, Yves F. and Mingeot-Leclercq, Marie-Paule},
  issn         = {0005-2736},
  keyword      = {Surfactin,Membrane interaction,Phase coexistence,Laurdan and DPH,fluorescence,Ellipsometry,AFM},
  language     = {eng},
  number       = {2},
  pages        = {801--815},
  publisher    = {Elsevier},
  series       = {Biochimica et Biophysica Acta - Biomembranes},
  title        = {Effects of surfactin on membrane models displaying lipid phase separation},
  url          = {http://dx.doi.org/10.1016/j.bbamem.2012.11.007},
  volume       = {1828},
  year         = {2013},
}