Design and biological activity of beta-hairpin-like antimicrobial peptide

In the current study, we synthesized a 16-residue-long peptide VR with the aim of inspecting the feasibility to design beta-hairpin-like antimicrobial peptide. The peptide was designed by alternating arrangement of arginine and valine and linking two stranded antiparallel beta-sheet with a short loop segment (DPG) and a disulfide bridge. Antimicrobial and hemolytic activities were investigated. Melittin was chosen as a control peptide. We also tested bactericidal kinetics and salt sensitivity. Results show that VR had similar antibacterial activity compared with melittin. However, VR displayed much less hemolytic activity than melittin. These results suggest that VR had higher cell selectivity than melittin. The antibacterial activity of VR was not inhibited in the presence of 25 and 50 mmol/L NaCl. VR still possessed antibacterial activity in the presence of 100 mmol/L NaCl. Collectively, the de novo peptide VR displayed high antimicrobial activity, low hemolytic activity, and salt resistant, indicating that VR was a promising candidate for novel antimicrobial applications.