title: The antimicrobial peptide microcin J25 stabilizes the gel phase of bacterial model membranes.
abstract: The bacterial membrane interaction of the antimicrobial peptide microcin J25 was studied with the probe-free techniques Langmuir monolayers and infrared spectroscopy. Membrane model systems composed by phosphatidylethanolamine:phosphatidylglycerol 7:3, which mimic the cytoplasmic membrane of Gram negative bacteria, were used in both monolayer and bilayer approaches. The peptide reduced the transition surface pressure of the expanded-to-condensed lipid monolayer states, as well as increased the gel-to-liquid crystalline transition temperature in bilayers, indicating a stabilization of membrane ordered state. In addition, a reduction of the surface pressure at which condensed domains appeared was observed upon mixed monolayers compression after microcin J25 adsorption. The results indicate a favorable interaction of microcin J25 with bacterial membrane model systems. Also, the effects on the ordered phases stabilization are discussed in terms of the biological effects observed in membranes of sensitive cells.
authors: Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI San Miguel de Tucumán, Argentina.
authors: M R
authors: MR
authors: Rintoul
authors: Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI San Miguel de Tucumán, Argentina.
authors: R D
authors: RD
authors: Morero
authors: Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI San Miguel de Tucumán, Argentina. Electronic address: fdupuy@fbqf.unt.edu.ar.
authors: F G
authors: FG
authors: Dupuy
mesh_terms: D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001430:Bacteriocins / Q000494:pharmacology*; D008051:Lipid Bilayers / Q000737:chemistry*; D008567:Membranes, Artificial; D044367:Phase Transition; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D010714:Phosphatidylethanolamines; D010715:Phosphatidylglycerols; D010743:Phospholipids; C020411:microcin; C483858:phosphatidylethanolamine
keywords: Bacterial membrane model systems; Microcin J25; Ordered lipid phase stabilization