A novel antimicrobial peptide screened by a

Area of Science:

• Biochemistry
• Molecular Biology
• Marine Biotechnology

Background:

• Antimicrobial peptides (AMPs) are crucial in combating pathogenic microorganisms.
• Developing novel AMPs is vital due to increasing antibiotic resistance.
• Ferritin fragments are unexplored sources for AMP discovery.

Purpose of the Study:

• To screen and characterize a novel AMP from the large yellow croaker.
• To investigate the antimicrobial activity and mechanism of the novel peptide Lc1687.
• To assess the stability and hemolytic activity of Lc1687 for potential therapeutic applications.

Main Methods:

• Screening of AMPs using a B. subtilis system.
• Bioinformatics and circular dichroism for structural analysis.
• Purification of recombinant Lc1687 (rLc1687) from E. coli.
• Antimicrobial activity assays against various bacteria and parasites.
• Microscopy (SEM, TEM) and gel retardation assays for mechanism elucidation.
• Stability assays (temperature, pH, UV) and hemolytic activity tests.

Main Results:

• A novel 51-amino acid AMP, Lc1687, was identified from large yellow croaker ferritin.
• Lc1687 demonstrated potent activity against Gram-positive and Gram-negative bacteria and Scuticociliatida.
• Mechanism involves targeting and disrupting bacterial cell membranes via pore formation and leakage.
• Lc1687 showed high stability across a wide range of temperatures, pH, and UV exposure.
• Minimal hemolytic activity suggests potential for clinical use.

Conclusions:

• Lc1687 is the first confirmed AMP derived from a ferritin fragment.
• The peptide exhibits broad-spectrum antimicrobial activity and a membrane-disrupting mechanism.
• Lc1687 is a stable and potentially safe candidate for developing novel antibacterial and anti-parasitic therapies.