A review: The active peptide of lactoferrin

Abstract

A potent antimicrobial peptide, ‘lactoferricin’, was found to be generated upon gastric pepsin cleavage of lactoferrin. The active peptide consists mainly of a loop of 18 amino acid residues, derived from the N‐terminal region of the lactoferrin molecule. Like various other antimicrobial peptides that display membrane‐disruptive properties, it contains a high proportion of basic amino acid residues. A physiologically diverse range of micro‐organisms was tested and found to be susceptible to inhibition by this natural peptide including Gram‐negative and Gram‐positive bacteria, yeasts and filamentous fungi. Its antimicrobial effect against sensitive micro‐organisms was lethal. Electron microscopy studies revealed that it induces a profound change in cell ultrastructural features and causes substantial cell damage in bacteria and fungi. These findings suggest the possibility that active peptides of lactoferrin may have a role in the host defense against microbial disease. If produced in substantial quantities in vivo such peptides could have important physiological significance, especially in nursing infants.