Bactericidal pore-forming pardaxin (Pa4) permeabilized both lipid and lipopolysaccharide membranes. Five paralogues are known: Pa1, 2, 3, 4, and 5, all nearly identical to each other. The 3-d structure of Pa4 is known. It forms a helix-turn-helix conformation resembling a horseshoe (Bhunia et al., 2010).