Deletion of all cysteines in tachyplesin I abolishes hemolytic activity and retains antimicrobial activity and lipopolysaccharide selective binding

The role of amphipathicity using an analogue of tachyplesin 1(TP-1), CDT (KWFRVYRGIYRRR-N[H.sub.2]), in which all four cysteines were deleted were investigated. The properties help to explain that cysteine residues may not contribute to antimicrobial activity and that the loss of hemolytic activity is due to lack of hydrophobicity and amphipathicity.