Antimicrobial activity, bactericidal mechanism and LPS-neutralizing activity of the cell-penetrating peptide pVEC and its analogs

✍ Scribed by Yong Hai Nan; Il-Seon Park; Kyung-Soo Hahm; Song Yub Shin

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 891 KB
• Volume: 17
• Category: Article
• ISSN: 1075-2617
• DOI: 10.1002/psc.1408

✦ Synopsis

__p__VEC is a cell‐penetrating peptide derived from the murine vascular endothelial‐cadherin protein. To evaluate the potential of __p__VEC as antimicrobial peptide (AMP), we synthesized __p__VEC and its analogs with Trp and Arg/Lys substitution, and their antimicrobial and lipopolysaccharide (LPS)‐neutralizing activities were investigated. __p__VEC and its analogs displayed a potent antimicrobial activity (minimal inhibitory concentration: 4–16 μM) against Gram‐positive and Gram‐negative bacteria but no or less hemolytic activity (less than 10% hemolysis) even at a concentration of 200 μM. These peptides induced a near‐complete membrane depolarization (more than 80%) at 4 μM against Staphylococcus aureus and a significant dye leakage (35–70%) from bacterial membrane‐mimicking liposome at a concentration as low as 1 μM. The fluorescence profiles of __p__VEC and its analogs in dye leakage from liposome and membrane depolarization were similar to those of a frog‐derived AMP, magainin 2. These results suggest that __p__VEC and its analogs kill bacteria by forming a pore or ion channel in the cytoplasmic membrane. __p__VEC and its analogs significantly inhibited nitric oxide production or tumor necrosis factor‐α release in LPS‐stimulated mouse macrophage RAW264.7 cells at 10 to 50 μM, in which RAW264.7 were not damaged. Taken together, our results suggest that __p__VEC and its analogs with potent antimicrobial and LPS‐neutralizing activities can serve as AMPs for the treatment of microbial infection and sepsis. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.