Shutting Down Shigella Secretion: Characterizing Small Molecule Type Three Secretion System ATPase Inhibitors

• DOI: 10.1021/acs.biochem.8b01077
• Publication Date: 2018-11-21T12:52:45Z
• Authors: Heather B. Case; Dominic S. Mattock; Nicholas E. Dicke...
• Keywords: Adenosine Triphosphatases; 570; 0303 health sciences; Binding Sites; Host Microbial Interactions; Virulence; Shigella flexneri; Molecular Docking Simulation; Chemistry; Kinetics; 03 medical and health sciences; small molecule type three secretion system; ATPase inhibitors; Genes, Bacterial; Type III Secretion Systems; Humans; Enzyme Inhibitors; HeLa Cells

Many important human pathogens rely on one or more type three secretion systems (T3SSs) to inject bacterial effector proteins directly into the host cell cytoplasm. Secretion of protein through needlelike apparatus (T3SA) is essential for pathogen virulence and relies a highly conserved ATPase at base apparatus, making it an attractive target anti-infective therapeutics. Here, we leveraged ability purify active oligomeric Shigella T3SS provide kinetic analyses inhibitors Spa47. In agreement with in silico docking simulations, displayed noncompetitive inhibition profiles efficiently reduced Spa47 activity IC50s as low 52 ± 3 μM. Two functioned well vivo, nearly abolishing without significantly affecting growth phenotype HeLa viability. Furthermore, characterization complexes vitro T3SA formation vivo showed that do not function disruption oligomers by preventing formation. Together, these findings suggest targeting may be effective means combating infection shutting down presentation antigenic tip aid clearing developing pan-Shigella immunological memory. summary, this first report only small number studies characterizing general. The work presented here provides much-needed insight mechanisms strong platform evaluating non-antibiotic therapeutics other ATPases.