Structure-based discovery of phospholipase A1 (PlaF) inhibitors in Pseudomonas aeruginosa using integrated in silico and experimental approaches

Phospholipase A1 (PlaF) is a membrane-bound virulence factor in Pseudomonas aeruginosa, involved in glycerophospholipid remodeling and host-pathogen signaling. Inhibiting PlaF represents a promising strategy to reduce the virulence and pathogenesis of multidrug-resistant P. aeruginosa. In this study, a library of 114 small molecules spanning seven chemical classes was evaluated using an integrated multi-step screening workflow. Compounds were subjected to drug-likeness filtering, molecular docking, free energy analysis, antimicrobial susceptibility testing, in-silico mutational analysis, and 100 ns molecular dynamics simulations. Among the tested scaffolds, two lead candidates —B4 and C2 — showed strong binding affinity to PlaF, structural stability, and favorable toxicity profiles. B4 is a methyl 3-methoxythiophene derivative with a fluorinated benzamido group, while C2 is a thioureido-substituted compound. These findings support B4 and C2 as promising scaffolds for PlaF inhibition and hold potential for advancing anti-virulence drug discovery against P. aeruginosa, offering a novel therapeutic approach to combat antibiotic resistance.