Effects of net charge and the number of positively charged residues on the biological activity of amphipathic α-helical cationic antimicrobial peptides
The widespread use of classical antibiotics has resulted in the emergence of many antibiotic-resistant strains. Cationic antimicrobial peptides (AMPs) have become important candidates as potential therapeutic agents. Cationic AMPs of the α-helical class have two unique features: a net positive charge of at least +2 and an amphipathic character, with a non-polar face and a polar/charged face.
We previously designed a peptide V13K from our original α-helical antimicrobial peptide V681, which had excellent antimicrobial activity but also exhibited high toxicity . D-V13K showed greater antimicrobial activity, no toxicity and excellent stability to proteolytic digestion compared to D-V681. The valine to lysine substitution in the center of the non-polar face is the first report of a specificity determinant in α-helical antimicrobial peptides between eukaryotic and prokaryotic cells. The hydrophobic residues on the non-polar face of the helix played a more important role in...