Directed Evolution of AtMP2 Peptide: Unlocking Enhanced Antibacterial Potential from Anabas testudineus

Area of Science:

• Biochemistry and Molecular Biology
• Pharmacology
• Marine Biology

Background:

• Antimicrobial peptides (AMPs) like AtMP1 and AtMP2 from climbing perch (Anabas testudineus) exhibit antibacterial and anticancer properties.
• Existing AMPs offer potential but require optimization for enhanced efficacy and safety.
• The epidermal mucus of Anabas testudineus is a source of bioactive peptides.

Purpose of the Study:

• To enhance the antimicrobial activity of the AtMP2 peptide through systematic-directed evolution.
• To evaluate the antibacterial efficacy and cytotoxicity of modified AtMP2 variants.
• To investigate the binding interactions of modified peptides with bacterial target proteins.

Main Methods:

• Generation of AtMP2 variants using systematic-directed evolution.
• Characterization of peptide variants using APD3, CAMP, and AMPFun.
• Antimicrobial activity assessment via Minimum Inhibitory Concentration (MIC) and Kirby-Bauer Disk Diffusion.
• Cytotoxicity evaluation using SRB assay on HS-27 and Vero cell lines.
• Molecular docking simulations using ZDOCK and HPEPDOCK servers.

Main Results:

• Two synthesized variants, AtMP2-1 and AtMP2-2, displayed superior antimicrobial activity against Gram-positive bacteria compared to native AtMP2.
• AtMP2-1 and AtMP2-2 showed no significant cytotoxicity on human cell lines at 20 μg/mL.
• Docking analysis revealed strong binding affinities of AtMP2-1 and AtMP2-2 to essential bacterial proteins like SecA, RpoB, and GyrA.

Conclusions:

• Modified AtMP2 peptides (AtMP2-1, AtMP2-2) derived from Anabas testudineus possess enhanced antibacterial properties and are safe for human use.
• These peptides represent promising candidates for developing novel therapeutic agents against bacterial infections.
• Further research into their specific mechanisms of action is warranted for applications in wound healing and cancer therapy.