title: Interaction of aurein 1.2 and its analogue with DPPC lipid bilayer.
abstract: Antibacterial peptides have potential as novel therapeutic agents for bacterial infections. Aurein 1.2 is one of the smallest antibacterial peptides extracted from an anuran. LLAA is a more active analogue of aurein 1.2. Antibacterial peptides usually accomplish their function by interacting with bacterial membrane selectively. In this study, we tried to find the reasons for the stronger antibacterial activity of LLAA compared with aurein 1.2. For this purpose, the interaction of aurein 1.2 and LLAA with dipalmitoylphosphatidylcholine (DPPC) was investigated by molecular dynamics (MD) simulation. In addition, the structure of peptides and their antibacterial activity were investigated by circular dichroism (CD) and dilution test method, respectively. MD results showed that LLAA is more flexible compared with aurein 1.2. Furthermore, LLAA loses its structure more than aurein 1.2 in the DPPC bilayer. A higher amount of water molecules penetrate into bilayer in the presence of LLAA relative to aurein 1.2. According to the antibacterial result that indicated LLAA is remarkably more active than aurein 1.2, it can be concluded that flexibility of the peptide is a determining factor in antibacterial activity. Probably, flexibility of the peptides facilitates formation of effective pores in the lipid bilayer.
authors.affiliation: Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Sajjadiyan
authors.affiliation: Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran.
authors.forename: Nasim
authors.initials: N
authors.lastname: Cheraghi
authors.affiliation: Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran. sarah@iasbs.ac.ir.
authors.forename: Sarah
authors.identifier: http://orcid.org/0000-0002-3758-5693
authors.initials: S
authors.lastname: Mohammadinejad
authors.affiliation: Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran.
authors.forename: Leila
authors.initials: L
authors.lastname: Hassani
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000378:metabolism*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000378:metabolism*; D006860:Hydrogen Bonding; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D011485:Protein Binding; D011487:Protein Conformation; D014867:Water / Q000378:metabolism
chemical_list: D023181:Antimicrobial Cationic Peptides; D008051:Lipid Bilayers; C506635:aurein 1.2 peptide; D014867:Water; D015060:1,2-Dipalmitoylphosphatidylcholine
keywords: Antibacterial peptides; Aurein 1.2; DPPC bilayer; LLAA; Molecular dynamics simulation