A High-Throughput Assay for Developing Inhibitors of PhoP, a Virulence Factor of Mycobacterium tuberculosis

Title:A High-Throughput Assay for Developing Inhibitors of PhoP, a Virulence Factor of Mycobacterium tuberculosis

Volume: 19 Issue: 10

Author(s): Liqin Wang, Miao Xu, Noel Southall, Wei Zheng and Shuishu Wang

Affiliation:

Keywords: High-throughput screening, PhoP inhibitors, tuberculosis, FRET, protein-DNA complex, TB drugs.

Abstract: Background: Tuberculosis (TB) kills over 1.5 million people per year despite the available anti-TB drugs. The long duration needed to treat TB by the current TB drugs, which target the essential cellular activities, inevitably leads to the emergence of drug-resistance. The emergence of drug-resistant TB prompts for an urgent need for new and more effective drugs.

Objective: The response regulator PhoP, an essential virulence factor of Mycobacterium tuberculosis (MTB), is an attractive target for developing novel anti- TB drugs. This study aims to develop a robust high-throughput screening assay to identify PhoP inhibitors that disrupt the PhoP-DNA binding.

Method: Guided by the crystal structure of the PhoP-DNA complex, we designed and developed an assay based on Foster resonance energy transfer (FRET) by labeling Cy3 on the DNA and Cy5 on PhoP. We screened compound libraries for inhibitors that dissociated the PhoP-DNA complex by detection of the FRET signal. Hits were confirmed for their direct binding to PhoP by thermal shift assays.

Results: From a test screening of ~6,000 bioactive compounds and approved drugs, three active compounds were identified that directly bound to PhoP and inhibited the PhoP-DNA interactions. These three PhoP inhibitors can be further developed to improve potency and are useful to study the mechanism of inhibition.

Conclusion: Our results demonstrated that this FRET-based PhoP-DNA binding assay is valid for additional compound library screening to identify new leads for developing novel TB drugs that target the virulence of MTB.

Cite this article as:

Wang Liqin, Xu Miao, Southall Noel, Zheng Wei and Wang Shuishu, A High-Throughput Assay for Developing Inhibitors of PhoP, a Virulence Factor of Mycobacterium tuberculosis, Combinatorial Chemistry & High Throughput Screening 2016; 19 (10) . https://dx.doi.org/10.2174/1386207319666161010163249

DOI https://dx.doi.org/10.2174/1386207319666161010163249	Print ISSN 1386-2073
Publisher Name Bentham Science Publisher	Online ISSN 1875-5402