Interaction of the antimicrobial peptide dicynthaurin with membrane phospholipids at the air-liquid interface.
This paper reports the first study on the interaction of the antimicrobial peptide dicynthaurin with 1,2-dipalmitoyl-glycerophosphatidyl-glycerol investigated in monolayers at the air-liquid interface. The influence of the peptide on the two-dimensional phase behavior of the negatively charged lipid was elucidated by means of pressure-area isotherm measurements, fluorescence microscopy, and grazing incidence X-ray diffraction measurements. The pure peptide forms a stable monolayer at the air-liquid interface up to 30 mN/m as shown for both the monomeric and the dimeric cynthaurins. The peptide lipid interaction was monitored in isotherm measurements showing a strong adsorption of the peptide and stabilization at the interface promoted by the lipid monolayer. The X-ray diffraction measurements in agreement with fluorescence microscopy studies showed that the peptide destabilizes the condensed chain lattice, leading to a complete fluidization of the condensed lipid phase on physiological buffer. The adsorption of the peptide to the negatively charged lipid monolayer and the fluidization of the condensed chain lattice suggest a direct link to the peptides' ability to expand the bacterial membrane that would be relevant for the in vivo mode of action.
Majerowicz
Monika
M
Institute of Medical Physics and Biophysics, University of Leipzig, 04107 Leipzig, Germany.
Waring
Alan J
AJ
Wen
Shaoying
S
Bringezu
Frank
F
D000388:Air; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D005990:Glycerol / Q000031:analogs & derivatives* / Q000737:chemistry; D008856:Microscopy, Fluorescence; D010168:Palmitates / Q000737:chemistry*; D010316:Particle Size; D010455:Peptides / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D014867:Water / Q000737:chemistry
C520885:1,2-dipalmitoyl-glycerophosphatidyl-glycerol; D000900:Anti-Bacterial Agents; D010168:Palmitates; D010455:Peptides; D010743:Phospholipids; D012997:Solvents; C437228:dicynthaurin; D014867:Water; D005990:Glycerol