A recombinant lectin-like protein (MgLec-1) from Magallana gigas: Antimicrobial, antioxidant, and wound-healing promotion in infected diabetic wounds.

This study reports the successful recombinant production and characterization of a novel lectin-like protein, MgLec-1, from the Pacific oyster Magallana gigas, expressed in Escherichia coli. Purified MgLec-1 (13.39 kDa) exhibited potent, dose-dependent antibacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA), with a minimum inhibitory concentration (MIC) of 64 μg/mL and a minimum bactericidal concentration (MBC) of 128 μg/mL. Notably, its antimicrobial action was independent of binding to common monosaccharides or peptidoglycan, suggesting a non-canonical mechanism. Comprehensive mechanistic studies revealed that MgLec-1 induces bacterial agglutination, disrupts cell membrane integrity (validated by flow cytometry with 97 % cell death at 1 × MIC), and triggers substantial reactive oxygen species (ROS) generation. Furthermore, MgLec-1 not only inhibited MRSA biofilm formation but also effectively disrupted pre-established mature biofilms. Beyond its antimicrobial and anti-biofilm efficacy, MgLec-1 demonstrated significant antioxidant activity, scavenging DPPH and ABTS+ radicals with EC50 values of 71.94 μg/mL and 7.77 μg/mL, respectively. In a diabetic rat model of MRSA-infected wounds, topical application of MgLec-1 (64 μg/mL) potently promoted wound closure, achieving up to 94.51 % healing by day 13-significantly surpassing the model control (68.07 %)-and enhanced tissue regeneration, as confirmed by histological and Masson's trichrome staining. Collectively, these results position MgLec-1 as a distinctive, multifunctional therapeutic candidate that integrates direct anti-MRSA, anti-biofilm, antioxidant, and pro-healing activities, offering a promising non-antibiotic strategy for managing multidrug-resistant infections in diabetic wounds.