Identification of Small-Molecule Antagonists of the Pseudomonas aeruginosa Transcriptional Regulator PqsR: Biophysically Guided Hit Discovery and Optimization

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• 作者：Tobias Klein ; Claudia Henn ; Johannes C. de Jong ; Christina Zimmer ; Benjamin Kirsch ; Christine K. Maurer ; Dominik Pistorius ; Rolf M眉ller ; Anke Steinbach ; Rolf W. Hartmann
• 刊名：ACS Chemical Biology
• 出版年：2012
• 出版时间：September 21, 2012
• 年：2012
• 卷：7
• 期：9
• 页码：1496-1501
• 全文大小：272K
• 年卷期：v.7,no.9(September 21, 2012)
• ISSN：1554-8937

文摘

The Gram-negative pathogen Pseudomonas aeruginosa produces an intercellular alkyl quinolone signaling molecule, the Pseudomonas quinolone signal. The pqs quorum sensing communication system that is characteristic for P. aeruginosa regulates the production of virulence factors. Therefore, we consider the pqs system a novel target to limit P. aeruginosa pathogenicity. Here, we present small molecules targeting a key player of the pqs system, PqsR. A rational design strategy in combination with surface plasmon resonance biosensor analysis led to the identification of PqsR binders. Determination of thermodynamic binding signatures and functional characterization in E. coli guided the hit optimization, resulting in the potent hydroxamic acid derived PqsR antagonist 11 (IC₅₀ = 12.5 渭M). Remarkably it displayed a comparable potency in P. aeruginosa (IC₅₀ = 23.6 渭M) and reduced the production of the virulence factor pyocyanin. Beyond this, site-directed mutagenesis together with thermodynamic analysis provided insights into the energetic characteristics of protein鈥搇igand interactions. Thus the identified PqsR antagonists are promising scaffolds for further drug design efforts against this important pathogen.