title: Rational design of alpha-helical antimicrobial peptide with Val and Arg residues.
abstract: OBJECTIVE
  The amphipathic alpha-helical peptide is an important class of antimicrobial peptides. In this study, a 16-residue-long peptide (VGR16) composed of 8 Val residues in the nonpolar face and 5 Arg residues in the polar face was designed based on the helical wheel projection to produce antimicrobial peptide with improved antibacterial activity accompanied by decreased toxicity.
  
  
  METHODS
  Antimicrobial activity and toxicity against red blood cells and mammalian cells were investigated to evaluate the biological function of the peptide. In addition, bactericidal kinetics was tested.
  
  
  RESULTS
  Antimicrobial assays revealed that the peptide VGR16 showed antimicrobial activity and their MICs against gram-negative and gram-positive bacteria ranged from 16 microg/ml to 64 microg/ml. VGR16 also exhibited rapid bactericidal action. It was surprisingly found that the peptide displayed no hemolytic activity even at a concentration of 256 microg/ml. Cell culture assays indicated that the peptide VGR16 had low cytotoxicity against mammalian cells.
  
  
  CONCLUSIONS
  The results showed that the peptide could be a likely candidate for future antimicrobial applications.
authors: Laboratory of Molecular Nutrition and Immunity, Institute of Animal Nutrition, Northeast Agricultural University, Harbin 150030, China. mqqwill@163.com
authors: Qingquan
authors: Q
authors: Ma
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authors: A
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