Identification of Small Molecule Inhibitors of Staphylococcus aureus RnpA
AbstractStaphylococcus aureus RnpA is thought to be a unique dual functional antimicrobial target that is required for two essential cellular processes, precursor tRNA processing and messenger RNA degradation. Herein, we used a previously described whole cell-based mupirocin synergy assay to screen members of a 53,000 compound small molecule diversity library and simultaneously enrich for agents with cellular RnpA inhibitory activity. A medicinal chemistry-based campaign was launched to generate a preliminary structure activity relationship and guide early optimization of two novel chemical classes of RnpA inhibitors identified, phenylcarbamoyl cyclic thiophene and piperidinecarboxamide. Representatives of each chemical class displayed potent anti-staphylococcal activity, limited the protein’s in vitro ptRNA processing and mRNA degradation activities, and exhibited favorable therapeutic indexes. The most potent piperidinecarboxamide RnpA inhibitor, JC2, displayed inhibition of cellular RnpA mRNA turnover, RnpA-depletion strain hypersusceptibility, and exhibited antimicrobial efficacy in a wax worm model of S. aureus infection. Taken together, these results establish that the whole cell screening assay used is amenable to identifying small molecule RnpA inhibitors within large chemical libraries and that the chemical classes identified here may represent progenitors of new classes of antimicrobials that target RnpA. View Full-Text
- Supplementary File 1:
ZIP-Document (ZIP, 568 KB)
Share & Cite This Article
Colquhoun, J.M.; Ha, L.; Beckley, A.; Meyers, B.; Flaherty, D.P.; Dunman, P.M. Identification of Small Molecule Inhibitors of Staphylococcus aureus RnpA. Antibiotics 2019, 8, 48.
Colquhoun JM, Ha L, Beckley A, Meyers B, Flaherty DP, Dunman PM. Identification of Small Molecule Inhibitors of Staphylococcus aureus RnpA. Antibiotics. 2019; 8(2):48.Chicago/Turabian Style
Colquhoun, Jennifer M.; Ha, Lisha; Beckley, Andrew; Meyers, Brinkley; Flaherty, Daniel P.; Dunman, Paul M. 2019. "Identification of Small Molecule Inhibitors of Staphylococcus aureus RnpA." Antibiotics 8, no. 2: 48.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.