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. Graphical Abstract