The biologically important surfactin lipopeptide induces nanoripples in supported lipid bilayers.
Under specific conditions, lipid membranes form ripple phases with intriguing nanoscale undulations. Here, we show using in situ atomic force microscopy (AFM) that the biologically important surfactin lipopeptide induces nanoripples of 30 nm periodicity in dipalmitoyl phosphatidylcholine (DPPC) bilayers at 25 degrees (i.e. well below the pretransition temperature of DPPC). Whereas most undulations formed the classical straight orientation with characteristic angle changes of 120 degrees , some of them also displayed unusual circular orientations. Strikingly, ripple structures were formed at 15% surfactin but were rarely or never observed at 5 and 30% surfactin, emphasizing the important role played by the surfactin concentration. Theoretical simulations corroborated the AFM data by revealing the formation of stable surfactin/lipid assemblies with positive curvature.
Brasseur
Robert
R
Centre de Biophysique Moléculaire Numérique, Faculté Universitaire des Sciences Agronomiques de Gembloux, Passage des Déportés 2, B-5030 Gembloux, Belgium.
Braun
Nathalie
N
El Kirat
Karim
K
Deleu
Magali
M
Mingeot-Leclercq
Marie-Paule
MP
Dufrêne
Yves F
YF
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D020816:Amino Acid Motifs; D000998:Antiviral Agents / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D055666:Lipopeptides; D018625:Microscopy, Atomic Force; D008954:Models, Biological; D036103:Nanotechnology; D010456:Peptides, Cyclic / Q000737:chemistry*; D010507:Periodicity; D013499:Surface Properties
D000998:Antiviral Agents; D008051:Lipid Bilayers; D055666:Lipopeptides; D010456:Peptides, Cyclic; C009365:surfactin peptide; D015060:1,2-Dipalmitoylphosphatidylcholine