Novel inhibitors of acetate kinase from Francisella tularensis

Abstract

Developed as a bioweapon in the 1940's, Francisella tularensis is the pathogenic bacteria responsible for tularemia, or rabbit fever. In order to develop new treatments for weaponized strains of F. tularensis, potential inhibitors F. tularensis acetate kinase were identified in silico and experimentally tested. Often kinase activity is probed using relatively expensive NADH‐linked assays. Here, we utilized an inexpensive kinetic assay that monitors the production of acetyl phosphate via reaction with hydroxylamine to rapidly characterize potential inhibitors of F. tularensis acetate kinase. The KM values for ATP and acetate were determined to be 1.4 and 15.4 mM, respectively, and the Vmax was determined to be 40.6 μmol min−1 mg−1. Computational screening using DOCK allowed the identification of potential inhibitors from the National Cancer Institute's Developmental Therapeutics Program. Ten compounds were obtained and tested, and two of these reduce the activity of F. tularensis acetate kinase significantly, though at relatively high concentrations. Using these structures as lead compounds, we are mining the database for similar compounds to test as inhibitors. This research was funded by the Wabash College Haines Biochemistry Fund.