Publications (2)3.74 Total impact
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Article: Biochemical Property and In Vivo Efficacies of Novel Val/Arg-rich Antimicrobial Peptide.
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ABSTRACT: A novel α-helical antimicrobial peptide G6 rich in Val/Arg residues has been screened previously. In this study, we further evaluated the biochemical stability, interaction with whole bacteria, and in vivo therapeutic or prophylactic role of the peptide in Salmonella typhimurium-infected mice. The results showed that G6 exhibited strong resistance to pH, heat, and salts. But G6 lost the antimicrobial activity when treated with proteolytic enzymes. G6 had no toxicity on mammalian cell. An intraperitoneal model of sepsis caused by Salmonella typhimurium was established in mice. G6 was administered intraperitoneally 1 h before or after mice were infected with Salmonella typhimurium. For the mice given peptide post-bacterial infection, the mortality of the mice and the peritoneal bacterial counts were significantly lower in the groups that were administered 2.5 mg/kg BW and 5.0 mg/kg BW of G6 (P < 0.05) compared to the PBS-treated group. Similar trend was obtained when G6 was given 1 h prior to Salmonella typhimurium infection. Peptide-membrane experiments showed that G6 was effective in permeabilizing the outer and inner membrane in a dose dependent manner, indicating that the peptide targets the cell membrane. Taken together, the results revealed that the peptide G6 may provide a useful alternative to antibiotic agents to treat or prevent bacterial infections.Protein and Peptide Letters 05/2012; 19(11):1144-8. · 1.94 Impact Factor -
Article: Cell selectivity and interaction with model membranes of Val/Arg-rich peptides.
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ABSTRACT: Antimicrobial peptides are major components of the innate self-defence system and a large number of peptides have been designed to study the mechanism of action. In the present study, a small combinatorial library was designed to study whether the biological activity of Val/Arg-rich peptides is associated with targeted cell membranes. The peptides were produced by segregating hydrophilic residues on the polar side and hydrophobic residues on the opposite side. The peptides displayed strong antimicrobial activity against Gram-negative and Gram-positive bacteria, but weak haemolysis even at a concentration of 256 µM. CD spectra showed that the peptides formed α-helical-rich structure in the presence of negatively charged membranes. The tryptophan fluorescence and quenching experiments indicated that the peptides bound preferentially to negatively charged phospholipids over zwitterionic phospholipids, which corresponds well with the biological activity data. In the in vivo experiment, the peptide G6 decreased the bacterial counts in the mouse peritoneum and increased survival after 7 days. Overall, a high binding affinity with negatively charged phospholipids correlated closely with the cell selectivity of the peptides and some peptides in this study may be likely candidates for the development of antibacterial agents.Journal of Peptide Science 03/2011; 17(7):520-6. · 1.80 Impact Factor
