FIGURE 5.

Liposome effects, LPS-binding, and anti-endotoxin activity of FFF21. A, effects of FFF21 on liposome leakage. The membrane-permeabilizing effect was recorded by measuring fluorescence release of carboxyfluorescein from 1,2-dioleoyl-sn-glycero-3-phoshoetanolamine/1,2-dioleoyl-sn-glycero-3-phosphoglycerol, monosodium salt (DOPE/DOPG) (negatively charged) liposomes. The experiments were performed in 10 mm Tris buffer. Values represents mean of triplicate samples. B, helical content of FFF21 peptide in presence of negatively charged liposomes (1,2-dioleoyl-sn-glycero-3-phoshoetanolamine/1,2-dioleoyl-sn-glycero-3-phosphoglycerol, monosodium salt). C, LPS-binding activities of peptides. 1, 2, and 5 μg of the indicated peptides were applied onto nitrocellulose membranes, followed by incubation with iodinated [¹²⁵I]LPS in PBS (containing 3% BSA). Unlabeled heparin (6 mg/ml) was added for competition of binding. LL-37 is included for comparison. D, anti-endotoxic effects in a monocyte model. Dose-dependent inhibitory effects on THP1-XBlue-CD14 stimulated by LPS are evaluated. Cells were stimulated with E. coli LPS (10 ng/ml), with and without addition of KTS43, FFF21, or LL-37 at 0.1–10 μm. LPS-stimulated cells without peptide were used as control.