title: Morphological changes induced by the action of antimicrobial peptides on supported lipid bilayers.
abstract: We utilized epifluorescence microscopy to investigate the morphological changes in labeled lipid bilayers supported on quartz surfaces (SLBs) induced by the interaction of cationic antimicrobial peptides with the lipid membranes. The SLBs were prepared from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and mixtures thereof as well as from Escherichia coli lipid extract. We succeeded in the preparation of POPG and POPG-rich SLBs without the necessity to use fusogenic agents such as calcium by using the Langmuir-Blodgett/Langmuir-Schaefer transfer method. The adsorption of the peptides to the SLBs was initially driven by electrostatic interactions with the PG headgroups and led to the formation of lipid protrusions bulging out from the lipid layer facing the bulk, originating particularly from domain boundaries and membrane defects. The shape, size, and frequency of the lipid protrusions are mainly controlled by the peptide macroscopic properties and the membrane composition. A restructuring of the lipid protrusions into other structures can also occur over time.
authors.affiliation: Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Halle, Germany.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Arouri
authors.forename: Volker
authors.initials: V
authors.lastname: Kiessling
authors.forename: Lukas
authors.initials: L
authors.lastname: Tamm
authors.forename: Margitta
authors.initials: M
authors.lastname: Dathe
authors.forename: Alfred
authors.initials: A
authors.lastname: Blume
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D010713:Phosphatidylcholines / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry; D055672:Static Electricity
chemical_list: D023181:Antimicrobial Cationic Peptides; C547315:KLAL peptide; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010715:Phosphatidylglycerols; C057561:1-palmitoyl-2-oleoylphosphatidylethanolamine; C060037:1-palmitoyl-2-oleoylglycero-3-phosphoglycerol; D002118:Calcium; C028694:1-palmitoyl-2-oleoylphosphatidylcholine