title: Interaction of the cationic peptide bactenecin with mixed phospholipid monolayers at the air-water interface.
abstract: The initial mechanism by which antimicrobial peptides target microbes occurs via electrostatic interactions; however, the mechanism is not well understood. We investigate the interaction of the antimicrobial peptide bactenecin with a 50:50 w:w% 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dimyristoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DMPG) phospholipid mixture at the air-water interface with different NaCl concentrations (0.01, 0.05, 0.1, 0.5 M) in the subphase. A larger shift of DPPC:DMPG isotherms was obtained for 0.1 M salt concentration at lower and higher pressures, demonstrating the influence of the negative charge of DMPG molecules and the screening of the electrostatic interaction by the salt concentration. Raman spectroscopy of monolayers demonstrated the presence of cysteine-cysteine bridges in bactenecin loops. The peptide adsorption in DPPC:DMPG monolayers observed by AFM images suggests a self-assembled aggregation process, starting with filament-like networks. Domains similar to carpets were formed and pore structures were obtained after a critical peptide concentration, according to the carpet model.
authors.affiliation: Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora, Rosales y Transversal, 83000 Hermosillo, Sonora, Mexico.
authors.forename: Ana B
authors.initials: AB
authors.lastname: López-Oyama
authors.forename: Pablo
authors.initials: P
authors.lastname: Taboada
authors.forename: María G
authors.initials: MG
authors.lastname: Burboa
authors.forename: Ezequiel
authors.initials: E
authors.lastname: Rodríguez
authors.forename: Víctor
authors.initials: V
authors.lastname: Mosquera
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Valdez
mesh_terms: D000388:Air; D002412:Cations / Q000737:chemistry; D008567:Membranes, Artificial; D010456:Peptides, Cyclic / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D002412:Cations; D008567:Membranes, Artificial; D010456:Peptides, Cyclic; D010743:Phospholipids; D014867:Water; C056454:bactenecin