“Multiplexed screen identifies aPseudomonas aeruginosa-specific small molecule targeting the outer membrane protein OprH and its interaction with LPS”

Abstract

SUMMARYThe surge of antimicrobial resistance threatens efficacy of current antibiotics, particularly againstPseudomonas aeruginosa, a highly resistant gram-negative pathogen. The asymmetric outer membrane (OM) ofP. aeruginosacombined with its array of efflux pumps provide a barrier to xenobiotic accumulation, thus making antibiotic discovery challenging. We adapted PROSPECT1, a target-based, whole-cell screening strategy, to discover small molecule probes that killP. aeruginosamutants depleted for essential proteins localized at the OM. We identified BRD1401, a small molecule that has specific activity against aP. aeruginosamutant depleted for the essential lipoprotein, OprL. Genetic and chemical biological studies identified that BRD1401 acts by targeting the OM β-barrel protein OprH to disrupt its interaction with LPS and increase membrane fluidity. Studies with BRD1401 also revealed an interaction between OprL and OprH, directly linking the OM with peptidoglycan. Thus, a whole-cell, multiplexed screen can identify species-specific chemical probes to reveal novel pathogen biology.