Lipopolysaccharide neutralization by a novel peptide derived from phosvitin

Area of Science:

• Biochemistry
• Immunology
• Pharmacology

Background:

• Sepsis, triggered by lipopolysaccharide (LPS), has high mortality due to lack of effective treatments.
• Current therapies do not adequately protect against LPS-mediated tissue damage and organ failure.
• Phosvitin-derived peptide Pt5 exhibits antibacterial properties.

Purpose of the Study:

• To develop and evaluate novel peptide mutants for enhanced endotoxin neutralization.
• To investigate the therapeutic potential of Pt5e in LPS-induced sepsis models.

Main Methods:

• Site-directed mutagenesis was used to generate Pt5 mutants.
• Bactericidal activity, LPS/lipoteichoic acid binding, and cytokine inhibition assays were performed.
• In vivo studies assessed Pt5e's efficacy in protecting against LPS-induced liver damage and endotoxemia.

Main Results:

• Pt5e demonstrated superior bactericidal activity against E. coli and S. aureus.
• Pt5e effectively bound to LPS and lipoteichoic acid.
• Pt5e significantly inhibited LPS-induced TNF-α and IL-1β release and reduced serum cytokine levels.
• Pt5e protected the liver from LPS damage and improved survival rates in endotoxemic mice.
• Pt5e showed no cytotoxicity or hemolytic activity.

Conclusions:

• Pt5e is a potent endotoxin-neutralizing agent.
• Pt5e exhibits significant therapeutic potential for treating LPS-induced sepsis.
• Pt5e represents a promising candidate for clinical development.