Rational Design of Broad-Spectrum Antimicrobial Peptides Derived from the Dengue Virus Capsid Alpha2 Sequence

Area of Science:

• Biochemistry
• Microbiology
• Drug Discovery

Background:

• Antimicrobial peptides (AMPs) are crucial in combating antibiotic resistance due to their membrane-disrupting mechanisms.
• Existing AMPs face limitations such as low efficacy, toxicity, and side effects.
• Developing novel AMPs with enhanced membrane disruption capabilities is essential.

Purpose of the Study:

• To design and evaluate novel amphiphilic antimicrobial peptides (AMPs) based on Dengue viral sequences.
• To address challenges of ineffective membrane disruption and improve antimicrobial performance.
• To investigate the mechanism of action, focusing on bacterial membrane destabilization.

Main Methods:

• Design of novel AMPs inspired by Dengue virus α2 sequence and G(IIKK)3I-NH2 (G3).
• Antimicrobial activity assessment using minimum inhibition concentration (MIC) and time-dependent killing assays.
• Investigation of membrane interactions using fluorescence assays (permeability, depolarization, leakage) and neutron reflection.

Main Results:

• Designed Dengue viral-inspired peptides (DVPs) exhibited lower MICs and faster killing than G3.
• DVP-3 demonstrated complete bacterial killing within 10 minutes.
• Fluorescence assays and neutron reflection revealed DVP-3 effectively disrupted the outer membrane (OM) more than the inner membrane (IM) of Gram-negative bacteria.

Conclusions:

• Novel Dengue viral-inspired AMPs, particularly DVP-3, show potent and rapid antimicrobial activity.
• These AMPs effectively destabilize bacterial membranes, offering improved antimicrobial performance.
• The study provides insights into AMP-membrane interactions and an effective in vitro evaluation approach for overcoming bacterial resistance.