title: Highly selective end-tagged antimicrobial peptides derived from PRELP.
abstract: BACKGROUND
  Antimicrobial peptides (AMPs) are receiving increasing attention due to resistance development against conventional antibiotics. Pseudomonas aeruginosa and Staphylococcus aureus are two major pathogens involved in an array of infections such as ocular infections, cystic fibrosis, wound and post-surgery infections, and sepsis. The goal of the study was to design novel AMPs against these pathogens.
  
  
  RESULTS
  Antibacterial activity was determined by radial diffusion, viable count, and minimal inhibitory concentration assays, while toxicity was evaluated by hemolysis and effects on human epithelial cells. Liposome and fluorescence studies provided mechanistic information. Protease sensitivity was evaluated after subjection to human leukocyte elastase, staphylococcal aureolysin and V8 proteinase, as well as P. aeruginosa elastase. Highly active peptides were evaluated in ex vivo skin infection models. C-terminal end-tagging by W and F amino acid residues increased antimicrobial potency of the peptide sequences GRRPRPRPRP and RRPRPRPRP, derived from proline arginine-rich and leucine-rich repeat protein (PRELP). The optimized peptides were antimicrobial against a range of gram-positive S. aureus and gram-negative P. aeruginosa clinical isolates, also in the presence of human plasma and blood. Simultaneously, they showed low toxicity against mammalian cells. Particularly W-tagged peptides displayed stability against P. aeruginosa elastase, and S. aureus V8 proteinase and aureolysin, and the peptide RRPRPRPRPWWWW-NH(2) was effective against various "superbugs" including vancomycin-resistant enterococci, multi-drug resistant P. aeruginosa, and methicillin-resistant S. aureus, as well as demonstrated efficiency in an ex vivo skin wound model of S. aureus and P. aeruginosa infection.
  
  
  CONCLUSIONS
  Hydrophobic C-terminal end-tagging of the cationic sequence RRPRPRPRP generates highly selective AMPs with potent activity against multiresistant bacteria and efficiency in ex vivo wound infection models. A precise "tuning" of toxicity and proteolytic stability may be achieved by changing tag-length and adding W- or F-amino acid tags.
authors.affiliation: Department of Pharmacy, Uppsala University, Uppsala, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Malmsten
authors.forename: Gopinath
authors.initials: G
authors.lastname: Kasetty
authors.forename: Mukesh
authors.initials: M
authors.lastname: Pasupuleti
authors.forename: Jan
authors.initials: J
authors.lastname: Alenfall
authors.forename: Artur
authors.initials: A
authors.lastname: Schmidtchen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000494:pharmacology*; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000382:microbiology; D016326:Extracellular Matrix Proteins / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D006801:Humans; D051379:Mice; D011552:Pseudomonas Infections / Q000188:drug therapy; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000472:pathogenicity; D012867:Skin / Q000293:injuries; D013203:Staphylococcal Infections / Q000188:drug therapy; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000472:pathogenicity; D014945:Wound Healing / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; C096382:PRELP protein, human