title: Structural basis for the enhanced activity of cyclic antimicrobial peptides: the case of BPC194.
abstract: We report the molecular basis for the differences in activity of cyclic and linear antimicrobial peptides. We iteratively performed atomistic molecular dynamics simulations and biophysical measurements to probe the interaction of a cyclic antimicrobial peptide and its inactive linear analogue with model membranes. We establish that, relative to the linear peptide, the cyclic one binds stronger to negatively charged membranes. We show that only the cyclic peptide folds at the membrane interface and adopts a β-sheet structure characterised by two turns. Subsequently, the cyclic peptide penetrates deeper into the bilayer while the linear peptide remains essentially at the surface. Finally, based on our comparative study, we propose a model characterising the mode of action of cyclic antimicrobial peptides. The results provide a chemical rationale for enhanced activity in certain cyclic antimicrobial peptides and can be used as a guideline for design of novel antimicrobial peptides.
authors.affiliation: Department of Biochemistry and Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands.
authors.forename: Jacek T
authors.initials: JT
authors.lastname: Mika
authors.forename: Gemma
authors.initials: G
authors.lastname: Moiset
authors.forename: Anna D
authors.initials: AD
authors.lastname: Cirac
authors.forename: Lidia
authors.initials: L
authors.lastname: Feliu
authors.forename: Eduard
authors.initials: E
authors.lastname: Bardají
authors.forename: Marta
authors.initials: M
authors.lastname: Planas
authors.forename: Durba
authors.initials: D
authors.lastname: Sengupta
authors.forename: Siewert J
authors.initials: SJ
authors.lastname: Marrink
authors.forename: Bert
authors.initials: B
authors.lastname: Poolman
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000494:pharmacology; D001703:Biophysics / Q000379:methods; D002462:Cell Membrane / Q000378:metabolism; D002942:Circular Dichroism; D003198:Computer Simulation; D004305:Dose-Response Relationship, Drug; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry*; D008567:Membranes, Artificial; D008968:Molecular Conformation; D010455:Peptides / Q000737:chemistry; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000494:pharmacology; D010539:Permeability; D011485:Protein Binding; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013997:Time Factors
chemical_list: D023181:Antimicrobial Cationic Peptides; C560863:BPC194; D008055:Lipids; D008081:Liposomes; D008567:Membranes, Artificial; D010455:Peptides; D010456:Peptides, Cyclic