Protease Stabilizing Antimicrobial Peptide D1018M Showed Potent Antibiofilm and Anti-Intracellular Bacteria Activity...

Area of Science:

• Microbiology
• Peptide Chemistry
• Infectious Diseases

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) is a significant threat, causing recurring infections via biofilms and intracellular invasion.
• Existing antimicrobial peptides like IDR-1018 and 1018M show promise but require improved protease tolerance and intracellular efficacy.
• Novel solutions are crucial to combat persistent MRSA infections.

Purpose of the Study:

• To synthesize and evaluate D-amino acid substituted peptides (D1018, D1018M) for enhanced antimicrobial and antibiofilm activity against MRSA.
• To assess the stability of these novel peptides against common proteases.
• To determine the potential of D1018M as a therapeutic agent for recurring MRSA infections.

Main Methods:

• Synthesis of D-amino acid substituted peptides (D1018, D1018M) based on IDR-1018 and 1018M.
• Antimicrobial and antibiofilm assays against MRSA.
• Protease stability testing using pepsin, trypsin, and cathepsin K.
• Evaluation of anti-intracellular MRSA activity.

Main Results:

• D-amino acid substitution increased antimicrobial activity (D1018) or maintained it (D1018M) against MRSA.
• Peptides D1018 and D1018M exhibited 2-32 times greater stability against proteases.
• Antibiofilm activity of D1018 increased 1.6-fold, and anti-intracellular activity of D1018M improved significantly (3.2-5.7 orders of magnitude).

Conclusions:

• D-amino acid substitution enhances the stability and efficacy of antimicrobial peptides against MRSA.
• D1018M shows remarkable improvement in combating intracellular MRSA and protease resistance.
• D1018M is a promising candidate for developing therapeutics against persistent and recurring MRSA infections.