Fig. 1: Optimized acylaminooxadiazoles inhibit trans-translation to kill N. gonorrhoeae.
A Zones used to guide synthetic strategy with characteristics that govern activity are indicated, and the structures of KKL-35 and MBX-4132 are shown. B Properties of the initial hit, KKL-35, and optimized inhibitor MBX-4132 (CC50 – half-maximal cytotoxic concentration against HeLa cells; MMS – murine liver microsome stability). C Inhibition of trans-translation in E. coli cells was monitored using a non-stop luciferase reporter. The average of two biological repeats is shown. D Inhibition of trans-translation in vitro was assayed using an E. coli S12 extract to express a truncated, non-stop nano-luciferase gene in the presence of a mutant tmRNA that added the remainder of the nano-luciferase protein. Trans-translation activity resulted in luminescence, and addition of MBX-4132 inhibited the reaction (black). As a control, a full-length nano-luciferase gene was used to demonstrate that MBX-4132 does not inhibit translation (blue). The percentage of activity compared to activity in absence of MBX-4132 is shown from the average of at least two repeats. E Time-kill assays using N. gonorrhoeae show that MBX-4132 is bactericidal at ≥4X MIC. Ceftriaxone (CRO) was used as a control. Counts below the detection limit (100 cfu/ml) were plotted at 100 cfu/ml. Source data are provided as a Source Data file.
