Table 2.

MICs, relative binding of peptides to LPS isolated from membrane of P. aeruginosa H103, and ability to permeabilize the outer membrane of P. aeruginosa H103

Peptide antibioticMIC (μg/ml)LPS binding (IC50 [μg/ml] for dansyl polymyxin B displacement)Maximal dansyl polymyxin B displacement (%)Outer membrane permeabilization to NPN (PC50 [μg/ml])
Polymyxin B0.1259.6800.65
Polymyxin E10.2512.0720.76
Gramicidin S8.050705
Colymycin M4.0>300a 0>300
  • a No significant displacement of dansyl polymyxin B was observed at all concentrations tested.