Discovery of PqsE Thioesterase Inhibitors for Using DNA-Encoded Small Molecule Library Screening.

TitleDiscovery of PqsE Thioesterase Inhibitors for Using DNA-Encoded Small Molecule Library Screening.
Publication TypeJournal Article
Year of Publication2020
AuthorsValastyan, JS, Tota, MR, Taylor, IR, Stergioula, V, Hone, GAB, Smith, CD, Henke, BR, Carson, KG, Bassler, BL
JournalACS Chem Biol
Date Published2020 Feb 21
KeywordsBacterial Proteins, Benzamides, DNA, Enzyme Inhibitors, Microbial Sensitivity Tests, Molecular Structure, Phthalic Acids, Pseudomonas aeruginosa, Small Molecule Libraries, Structure-Activity Relationship, Thiolester Hydrolases

<p> is a leading cause of hospital-acquired infections in the United States. PqsE, a thioesterase enzyme, is vital for virulence of , making PqsE an attractive target for inhibition. Neither the substrate nor the product of PqsE catalysis has been identified. A library of 550 million DNA-encoded drug-like small molecules was screened for those that bind to the purified PqsE protein. The structures of the bound molecules were identified by high throughput sequencing of the attached DNA barcodes. Putative PqsE binders with the strongest affinity features were examined for inhibition of PqsE thioesterase activity . The most potent inhibitors were resynthesized off DNA and examined for the ability to alter PqsE thermal melting and for PqsE thioesterase inhibition. Here, we report the synthesis, biological activity, mechanism of action, and early structure-activity relationships of a series of 2-(phenylcarbamoyl)benzoic acids that noncompetitively inhibit PqsE. A small set of analogs designed to probe initial structure-activity relationships showed increases in potency relative to the original hits, the best of which has an IC = 5 μM. Compound refinement is required to assess their activities as the current compounds do not accumulate in the cytosol. Our strategy validates DNA-encoded compound library screening as a rapid and effective method to identify catalytic inhibitors of the PqsE protein, and more generally, for discovering binders to bacterial proteins revealed by genetic screening to have crucial activities but whose biological functions have not been well-defined.</p>

Alternate JournalACS Chem Biol
PubMed ID31880429
PubMed Central IDPMC7036018
Grant List / HHMI / Howard Hughes Medical Institute / United States
F32 GM134583 / GM / NIGMS NIH HHS / United States
R37 GM065859 / GM / NIGMS NIH HHS / United States