Antimicrobial Activity of Antimicrobial Peptide LPcin-YK3 Derived from Bovine Lactophoricin.

We previously reported on lactophoricin (LPcin), a cationic α-helical antimicrobial peptide derived from bovine milk, which has antimicrobial effects on Candida albicans as well as Gram-positive and Gram-negative bacteria. In this study, we designed the LPcin-YK3 peptide, a shorter analog of LPcin, and investigated its antimicrobial activity. This peptide, consisting of 15 amino acids with + 3 net charges, was an effective antimicrobial agent against the on the Gram-positive strain, Staphylococcus aureus (MIC: 0.62 μg/ml). In addition, the hemolytic activity assay revealed that the peptide was not toxic to mouse and human erythrocytes up to 40 μg/ml. We also used circular dichroism spectroscopy to confirm that peptide in the presence of lipid has α-helical structures and later provide an overview of the relationship between each structure and antimicrobial activity. This peptide is a member of a new class of antimicrobial agents that could potentially overcome the problem of bacterial resistance caused by overuse of conventional antibiotics. Therefore, it could be used as a therapeutic or natural additive, particularly in the cosmetics industry.