Enhancement of antibacterial and lipopolysaccharide binding activities of a human lactoferrin peptide fragment by the addition of acyl chain

Cationic antibacterial peptides are potentially therapeutic in the treatment of sepsis, because of their amalgamated antibacterial and lipopolysaccharide-binding activities. We prepared acyl analogues of the peptide fragment of human lactoferrin, which originally had weak antibacterial activity. It was found that 12 carbon units constitute the optimal acyl chain length, enhancing the antibacterial activity and binding of lipopolysaccharide by up to two orders of magnitude. Lactoferrin-based lipopeptides approached the activity of polymyxin B, a lipopeptide of natural origin, but were also active against Gram-positive bacteria.