Development of an Antibacterial MAP Homologous to a Loop Region in Human Lactoferrin

We report on the antibacterial activities of an 11 residue peptide (FQWQRNMRKVR) homologous to just over half the loop region of human lactoferricin. The peptide, in the form of a multiple antingen peptide (MAP), exerted signi cant antibacterial e ects against a broad spectrum of bacteria including MRSA. Lactoferricin is an iron-binding glycoprotein belonging to the transferrin family and found in the speci c granules of neutrophils and in secretion uids such as tears, saliva and even milk. The pepsin digestion of bovine and human lactoferrin promotes the release of antibacterial peptides known as lactoferricin B and H respectively. This may be the key to its antimicrobial activity [1]. Lactoferricin is e ective against Gram-positive and negative bacteria as well as yeasts [2], its mechanism of action is however unknown. Human lactoferricin comprises two chains from residue 1-46 from the N-terminus of lactoferrin and includes an 18 residue loop formed by one of two disulphide bridges [1]. Recently, it has been shown that a much smaller peptide of only 11 residues (FQWQRNMRKVR), homologous to just over half the loop region has potent antibacterial activity and may account for all the activity of the larger peptides. Here we describe the computer analysis of the structure of such antibacterial MAP, and the experimental results of their antibacterial activities.