L5K5W peptide

A prototype de novo design of amphipathic helix involves only Lys and Leu residues (i.e. LK-peptides). Systematic studies revealed that 14-15 such residues are required to form a helical peptide that is active against bacteria (Blondelle SE & Houghten RA 1992 Biochemistry 31:12688-94). Shorter peptides are inactive, while longer peptides tend to be hemolytic. This 11mer peptide is only active after inserting an Trp, a well-known membrane anchor (see Chapter 4, Wang, G. ed. 2010 Antimicrobial peptides: discovery, design and novel therapeutic strategies, CABI). Remarkably, Shai and colleagues demonstrated (Animal model:mouse) the systemic effect of an KL-peptide, K6L9, seq LKLLKKLLKKLLKLL-NH2, consisting of a mixture of L, D-amino acids, that cures neutropenic mice infected with gentamicin-sensitive Pseudomonas aeruginosa and gentamicin-resistant Acinetobacter baumannii Gram-negative pathogenic bacteria (Braustein A et al 2004 Antimicrob Agents Chemother 48:3127-9). 9/2010; 9/2011 GW. L5K5W has Antimicrobial activity. L5K5W was found in de novo design.