Influence of Acetylation on the Mechanism of Action of Antimicrobial Peptide L163

Acetylation is a common modification of antimicrobial peptides. But the effects of acetylation on the mechanism of action of antimicrobial peptides remain unclear. Antimicrobial peptide L163 with high antimicrobial activity and broad spectrum was from an antimicrobial peptide database designed in our lab. L163 acetylated derivate, L163-Ac, was got by amino terminal modification with acetic anhydride. The effects of acetylation on the mechanism of action of L163 was investigated by fluorescence spectrophotometer, fluorescence microscope, ultraviolet spectroscopy, agarose gel electrophoresis in the present research. The results showed that acetylation could increase the antimicrobial activity of L163 by improving its ability of destroying the integrity of cell membrane bilayer and binding with DNA. Meanwhile, L163 and L163-Ac display their antimicrobial activity by disrupting the integrity of the cell membrane bilayer, with a certain level of cell membrane depolarization, ROS accumulation and DNA binding.