Rational design of α-helical antimicrobial peptide with Leu and Lys residues

Abstract:

[Objective] We designed a new antibacterial peptide LK. The peptide was composed of Leu residues in the nonpolar face and Lys residues in the polar face based on the helical wheel projection. The activities of LK were tested. [Methods] The secondary structure of LK was studied by Circular Dichroism (CD) spectrometry. Minimal inhibitory concentrations (MICs) of LK against Gram-positive and Gram-negative bacteria were determined. The stability, hemolytic activity and cytotoxicity of LK were also determined. [Results] LK had strong antimicrobial activities against detected bacteria with MICs of 2?4 μmol/L. LK exhibited high pH stability and salt tolerance. The peptide showed very weak hemolysis against human red blood cells and cytotoxicity against vero cells at its MICs. [Conclusion] These results suggest that LK might have potential as an attractive potential alternative to pharmaceutical antibiotics.

Key words:Antimicrobial peptide, α-Helical, Hemolysis, Cytotoxicity