Broad-Spectrum Antimicrobial Peptide Designed from the Mycobacterium tuberculosis Adenylate Kinase Structure, Inspired by Its LPS/LTA Dual Recognition

Abstract Broad-spectrum therapeutics targeting multidrug-resistant (MDR) Gram-negative and Gram-positive pathogens remain limited. Utilizing structural insights from Mycobacterium tuberculosis adenylate kinase (MtAdk), which uniquely recognizes both lipopolysaccharide (LPS) and lipoteichoic acid (LTA), we designed broad-spectrum antimicrobial peptides. Through incorporation of non-natural amino acids, terminal acylation, and arginine extension, we developed a lead candidate, YK-mAK-17, with remarkable stability, minimal resistance development, and broad-spectrum activity, particularly against carbapenem-resistant Acinetobacter baumannii (CRAB) and methicillin-resistant Staphylococcus aureus (MRSA). Mechanistic studies revealed an amphipathic α-helix with N-terminal C6 acylation that enhances membrane engagement, driving rapid bactericidal activity via multimodal disruption of membrane integrity and virulence pathways. In septic shock mouse models induced by CRAB and MRSA, YK-mAK-17 significantly improved survival and reduced organ damage. By combining MtAdk-inspired dual LPS/LTA recognition with targeted chemical modifications, YK-mAK-17 represents a promising antimicrobial candidate possessing broad-spectrum antibacterial and anti-inflammatory properties, highlighting the potential of structure-guided peptide design for addressing MDR infections.