Multiple Strategy Optimization of Specifically Targeted Antimicrobial Peptide Based on Structure-Activity...

Area of Science:

• Biochemistry
• Microbiology
• Peptide Science

Background:

• Traditional broad-spectrum antibiotics face bacterial resistance.
• Specifically targeted antimicrobial peptides (STAMPs) offer a novel approach with a membrane lytic mechanism.
• Current STAMPs have limitations in activity, specificity, and understanding structure-activity relationships.

Purpose of the Study:

• To enhance the activity and specificity of STAMPs.
• To investigate the impact of sequence modifications and phage display on STAMPs' biological functions.
• To develop a STAMP effective against Escherichia coli (E. coli).

Main Methods:

• A parental peptide sequence was modified through truncation, extension, charge alteration, and amphipathicity adjustment.
• A novel template modification involved attaching a phage-displayed peptide targeting E. coli to the STAMP sequence.
• Biological activities, including antibacterial efficacy, specificity, cytotoxicity, and stability, were evaluated.

Main Results:

• Peptide 13, with a phage-displayed peptide at the C-terminus, demonstrated superior narrow-spectrum antibacterial activity against E. coli compared to the parental peptide.
• The activity and specificity of peptide 13 were increased by 5.0 and 2.4 times, respectively.
• Peptide 13 exhibited low cytotoxicity and good stability under various conditions (salt, serum, pH, temperature).

Conclusions:

• The novel modification strategy significantly improved STAMPs' activity and specificity.
• Peptide 13 effectively targets and kills E. coli by disrupting the cytoplasmic membrane.
• These findings provide a foundation for developing more potent STAMPs to combat E. coli infections.