Tryptophan end-tagging of antimicrobial peptides for increased potency against Pseudomonas aeruginosa

• Published in: Biochimica et biophysica acta Vol. 1790; no. 8; pp. 800 - 808
• Main Authors: Pasupuleti, Mukesh, Chalupka, Anna, Mörgelin, Matthias, Schmidtchen, Artur, Malmsten, Martin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2009
• Subjects: Amino Acid Sequence; Animals; Anti-Bacterial Agents - metabolism; Anti-Bacterial Agents - pharmacology; Antimicrobial Cationic Peptides - chemistry; Antimicrobial Cationic Peptides - metabolism; Antimicrobial Cationic Peptides - pharmacology; Antimicrobial peptide; Clinical Medicine; Dermatologi och venereologi; Dermatology and Venereal Diseases; Hydrophobic tagging; Infectious Medicine; Infektionsmedicin; Kininogen; Klinisk medicin; Lipid Bilayers - metabolism; Lipopolysaccharides - metabolism; Medical and Health Sciences; MEDICIN; Medicin och hälsovetenskap; MEDICINE; Microbial Sensitivity Tests; Minimal inhibitory concentration assay; Models, Biological; Molecular Sequence Data; P. aeruginosa; Peptide; Permeability - drug effects; Potency enhancement; Protein Processing, Post-Translational - drug effects; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - growth & development; Sus scrofa; Tryptophan - metabolism; TSB; CF; AMP; Minimal inhibitory concentration assay; MIC; RDA; Hydrophobic tagging; Kininogen; CFU; VCA; Potency enhancement; Peptide; Antimicrobial peptide; P. aeruginosa
• ISSN: 0304-4165; 0006-3002; 1878-2434; 1872-8006; 1872-8006
• DOI: 10.1016/j.bbagen.2009.03.029

Due to increasing antibiotics resistance, antimicrobial peptides (AMPs) are receiving increased attention. Pseudomonas aeruginosa is a major pathogen in this context, involved, e.g., in keratitis and wound infections. Novel bactericidal agents against this pathogen are therefore needed. Bactericidal potency was monitored by radial diffusion, viable count, and minimal inhibitory concentration assays, while toxicity was probed by hemolysis. Mechanistic information was obtained from assays on peptide-induced vesicle disruption and lipopolysaccharide binding. End-tagging by hydrophobic amino acids yields increased potency of AMPs against P. aeruginosa, irrespective of bacterial proteinase production. Exemplifying this by two peptides from kininogen, GKHKNKGKKNGKHNGWK and KNKGKKNGKH, potency increased with tag length, correlating to more efficient bacterial wall and vesicle rupture, and to more pronounced P. aeruginosa lipopolysaccharide binding. End-tag effects remained at high electrolyte concentration and in the presence of plasma or anionic macromolecular scavengers. The tagged peptides displayed stability against P. aeruginosa elastase, and were potent ex vivo, both in a contact lens model and in a skin wound model. End-tagging, without need for post-peptide synthesis modification, may be employed to enhance AMP potency against P. aeruginosa at maintained limited toxicity.