Design of Hybrid Bioactive Peptides Derived From Cecropin and Cathepsin for Therapeutic Application

The escalating global health crisis of antimicrobial resistance demands the urgent development of novel therapeutic agents with new mechanisms of action. Bioactive peptides (BAPs), and specifically antimicrobial peptides (AMPs), represent a highly promising class of candidates due to their broad-spectrum activity and superior biocompatibility compared to conventional antibiotics. This manuscript presents a novel approach to drug discovery by designing multifunctional hybrid peptides through the strategic fusion of conserved domains from cecropin and cathepsin-derived sequences. We established an integrated in silico pipeline, utilizing machine learning for activity prediction and comprehensive ADMET profiling to rationally select three lead candidates with optimal physicochemical properties. Experimental validation confirmed their potent efficacy in vitro, demonstrating significant inhibition of both planktonic cultures and resilient biofilms. Critically, these peptides displayed a high safety profile, with no toxicity in erythrocyte or Galleria mellonella larvae models. To elucidate their mode of action, target fishing and molecular docking studies were conducted, revealing high-affinity interactions with essential E. coli enzymes, DNA gyrase, and thymidylate synthase. By combining computational design with robust biological validation, this work establishes a streamlined framework for accelerating anti-infective discovery and positioning these engineered hybrid BAPs as a promising class of antimicrobial agents.