1. Discovery of a Pseudomonas aeruginosa-specific small molecule targeting outer membrane protein OprH-LPS interaction by a multiplexed screen.
- Author
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Poulsen, Bradley E., Warrier, Thulasi, Barkho, Sulyman, Bagnall, Josephine, Romano, Keith P., White, Tiantian, Yu, Xiao, Kawate, Tomohiko, Nguyen, Phuong H., Raines, Kyra, Ferrara, Kristina, Golas, A. Lorelei, FitzGerald, Michael, Boeszoermenyi, Andras, Kaushik, Virendar, Serrano-Wu, Michael, Shoresh, Noam, and Hung, Deborah T.
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CELL envelope (Biology) , *DRUG discovery , *GRAM-negative bacteria , *SMALL molecules , *MEMBRANE proteins , *PROTEIN-protein interactions - Abstract
The surge of antimicrobial resistance threatens efficacy of current antibiotics, particularly against Pseudomonas aeruginosa , a highly resistant gram-negative pathogen. The asymmetric outer membrane (OM) of P. aeruginosa combined with its array of efflux pumps provide a barrier to xenobiotic accumulation, thus making antibiotic discovery challenging. We adapted PROSPECT, a target-based, whole-cell screening strategy, to discover small molecule probes that kill P. aeruginosa mutants depleted for essential proteins localized at the OM. We identified BRD1401, a small molecule that has specific activity against a P. aeruginosa mutant 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 pathogen biology. [Display omitted] • Target-focused, phenotypic, multiplexed screen with P. aeruginosa yields BRD1401 • BRD1401 is a species-specific inhibitor targeting LPS-OprH interaction at the OM • BRD1401 reveals novel link between P. aeruginosa OM/PG through OprH/OprL proteins Antimicrobial resistance (AMR) poses a serious threat to efficacious treatment of infectious diseases, prompting the WHO to prioritize therapeutic intervention against drug-resistant pathogens, one of which is Pseudomonas aeruginosa , a gram-negative, opportunistic bacterium. A key challenge in anti-pseudomonal drug discovery is low uptake of xenobiotics due to the impermeable, double-membraned cell envelope with a vast array of efflux pumps. To overcome this, we chose to target P. aeruginosa essential outer membrane proteins (OMPs) or OM-associated proteins (OMAPs), thus avoiding a cell permeation requirement. First, we describe a high-throughput multiplexed, whole-cell screening pipeline with a pool of genetic mutants depleted for essential OMPs/OMAPs, enabling the identification of small molecule probes or inhibitors with non-traditional MOA. Second, we show how such probes can be used to uncover biological interactions with the discovery of BRD1401, a P. aeruginosa -specific inhibitor with efficacy in an epithelial cell infection model. BRD1401 targets P. aeruginosa 's OMP OprH to disrupt its interaction with LPS and reveals a direct interaction between OprH and the essential OM lipoprotein, OprL, to link LPS and peptidoglycan in the cell wall. This is a comprehensive report of a whole-cell, multiplexed screen focused on specific OMP/OMAP targets that are essential in most gram-negative pathogens. We demonstrate how using this approach can be used to reveal biological interactions, in this case, about specific OMP/OMAPs and their role in cell envelope biology. Poulsen et al. describe a multiplexed, phenotypic chemical screening strategy focused on essential outer membrane (OM)-embedded or associated proteins in P. aeruginosa. They discover a species-specific inhibitor, BRD1401, with an MOA targeting OprH-LPS interaction at the OM. BRD1401 reveals biology linking the OM and PG in P. aeruginosa. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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