Biomolecular strategy for designing antibiotic–silver nanoparticles conjugate via nitrate reductase mediated β-lactamase inhibition with molecular docking insights

Résumé

In this study, mechanistic analysis using SDS-PAGE identified a 58 kDa protein as the biomolecule responsible for AgNPs biosynthesis and capping. Colorimetric microplate-based assay confirmed the protein as nitrate reductase, with structural preservation evidenced by a 29.68% activity increase (1.856 to 2.407 U/g) following AgNPs synthesis. Functionalization of AgNPs with ampicillin was indicated by SPR shift from 422.5 to 340.5 nm and disappearance of the FTIR band at 1736 cm⁻¹. Amp-AgNPs conjugate was stable (3 months), semi-spherical crystalline, polydisperse (PDI: 0.192), average diameter of 27.26 nm, zeta potential of - 24.9 mV, and showed broad pH (1-9) and thermal (5-55 °C) stability. Docking analysis revealed strong binding of ampicillin within the nitrate reductase catalytic pocket through hydrogen bonding, hydrophobic, and electrostatic interactions, confirming the conjugate stability. Amp-AgNPs (50 µg/mL) exhibited potent antibacterial activity against β-lactamase-producing bacteria with inhibition zones of 27.3 mm (Escherichia coli), 25.0 mm (Enterococcus faecalis), and 26.3 mm (Staphylococcus aureus), and MICs of 3.3, 4.7, and 4.3 µg/mL, respectively. SEM analysis revealed severe structural changes, indicating synergistic membrane disruption and antibiotic delivery. Amp-AgNPs potently inhibited β-lactamase in the iodometric assay, supporting their potential as alternative therapeutic agents. Future studies should focus on in vivo efficacy and expand this strategy to additional drug delivery applications.

Citer ce document

Accès au document

Texte intégral en lecture en ligne, réservé aux abonnés SPHAERO et aux membres de l'institution. Se connecter

Auteur(s)

Statistiques

Consultations : 1

Téléchargements : 0