An Enzyme-DNA Nanostructure with Enhanced Catalysis Accelerates MRSA Wound Healing

Antibiotic-resistant wound infections are a growing clinical challenge, as bacteria evade singletarget antimicrobials and persist within protective biofilms. Antimicrobial enzymes offer a promising alternative through their catalytic generation of bactericidal species, but their therapeutic utility is limited by instability in protease-rich wound environments. Here, we demonstrate that densely grafting short DNA strands onto lactoperoxidase (LPO), an innate immune enzyme, creates an enzyme-DNA nanostructure (Nano-Lac) with enhanced proteolytic stability and catalytic activity. Whereas polymer conjugation typically compromises enzyme activity, DNA functionalization increased LPO’s catalytic turnover by >10-fold. Mechanistic studies revealed conformational changes consistent with increased active-site accessibility and reduced accumulation of an inactive oxidized intermediate under excess H2O2. These enhancements translated into broad-spectrum activity against multidrug-resistant Escherichia coli (E. coli) and methicillinresistant Staphylococcus aureus (MRSA). Nano-Lac suppressed growth, disrupted biofilms, and compromised membrane integrity, outperforming vancomycin in vitro. In a murine MRSA wound model, daily topical Nano-Lac reduced bacterial burden ~2-fold and accelerated wound closure versus native LPO and vancomycin, without histopathological signs of toxicity. Extending beyond LPO, DNA functionalization also enhanced peroxidase activity across structurally distinct heme proteins, including myoglobin, hemoglobin, and cytochrome c. These findings establish DNA grafting as a general strategy to enhance heme-protein stability, catalysis, and therapeutic function.