In vitro and in vivo activity of antimicrobial peptides synthesized based on the insect defensin

Peptides. 2004 Jan;25(1):19-27. doi: 10.1016/j.peptides.2003.12.009.


Synthetic antimicrobial 9-mer peptides were designed from the amino acid sequence of an active site of insect defensin to increase the number of positively charged amino acid residues. These peptides, RLRLRIGRR-NH2, RLLLRIGRR-NH2 and RLYLRIGRR-NH2, showed strong antimicrobial activity against bacteria and fungus. These peptides showed no growth inhibition activity against murine fibroblasts or macrophages and no hemolytic activity against rabbit erythrocytes in vitro. Furthermore, the administration of these peptides protected mice from a lethal methicillin-resistant Staphylococcus aureus (MRSA) challenge. In addition, these peptides suppressed tumor necrosis factor alpha (TNF-alpha) gene expression and production induced by lipopolysaccharide (LPS) or lipoteichoic acid (LTA) in murine macrophages.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / chemical synthesis*
  • Anti-Bacterial Agents / pharmacology
  • Cell Line
  • Cytotoxins / pharmacology
  • Defensins / chemistry*
  • Gene Expression
  • Hemolysin Proteins / pharmacology
  • Insect Proteins / chemistry*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Peptides / chemical synthesis
  • Rabbits
  • Tumor Necrosis Factor-alpha / metabolism


  • Anti-Bacterial Agents
  • Cytotoxins
  • Defensins
  • Hemolysin Proteins
  • Insect Proteins
  • Peptides
  • Tumor Necrosis Factor-alpha