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

Authors

  • Yong Hai Nan,

    1. Department of Bio-Materials, Graduate School, Chosun University, Gwangju, Korea
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  • Il-Seon Park,

    1. Department of Bio-Materials, Graduate School, Chosun University, Gwangju, Korea
    2. Department of Cellular and Molecular Medicine, School of Medicine, Chosun University, Gwangju, Korea
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  • Kyung-Soo Hahm,

    1. Department of Bio-Materials, Graduate School, Chosun University, Gwangju, Korea
    2. Department of Cellular and Molecular Medicine, School of Medicine, Chosun University, Gwangju, Korea
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  • Song Yub Shin

    Corresponding author
    1. Department of Bio-Materials, Graduate School, Chosun University, Gwangju, Korea
    • Department of Cellular and Molecular Medicine, School of Medicine, Chosun University, Gwangju, Korea
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Song Yub Shin, Department of Cellular and Molecular Medicine, School of Medicine, Chosun University, Gwangju 501-759, Korea. E-mail: syshin@chosun.ac.kr

Abstract

pVEC is a cell-penetrating peptide derived from the murine vascular endothelial-cadherin protein. To evaluate the potential of pVEC as antimicrobial peptide (AMP), we synthesized pVEC and its analogs with Trp and Arg/Lys substitution, and their antimicrobial and lipopolysaccharide (LPS)-neutralizing activities were investigated. pVEC 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 pVEC 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 pVEC and its analogs kill bacteria by forming a pore or ion channel in the cytoplasmic membrane. pVEC 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 pVEC 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.

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