Physical properties and surface activity of surfactant-like membranes containing the cationic and hydrophobic peptide KL4.

A. SAENZ; O. CAÑADAS; LUIS A. BAGATOLLI; M.E. JOHNSON; C. CASALS

FEBS JOURNAL

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2006 vol. 273 p. 2515 - 2515

1742-464X

urfactant-like membranes containing the 21-residue peptide KLLLLKLLLLKLLLLKLLLLK (KL4), have been clinically tested as a therapeutic agent for respiratory distress syndrome in premature infants. The aims of this study were to investigate the interactions between the KL4 peptide and lipid bilayers, and the role of both the lipid composition and KL4 structure on the surface adsorption activity of KL4-containing membranes. We used bilayers of three-component systems [1,2-dipalmitoyl-phosphatidylcholine/1-palmitoyl-2-oleoyl-phosphatidylglycerol/palmitic acid (DPPC/POPG/PA) and DPPC/1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC)/PA] and binary lipid mixtures of DPPC/POPG and DPPC/PA to examine the specific interaction of KL4 with POPG and PA. We found that, at low peptide concentrations, KL4 adopted a predominantly alpha-helical secondary structure in POPG- or POPC-containing membranes, and a beta-sheet structure in DPPC/PA vesicles. As the concentration of the peptide increased, KL4 inte