Pyrazinoic Acid Inhibits Mycobacterial Coenzyme A Biosynthesis by Binding to Aspartate Decarboxylase PanD

作者：Gopal Pooja; Nartey Wilson; Ragunathan Priya; Sarathy Jansy; Kaya Firat; Yee Michelle; Setzer Claudia; Manimekalai Malathy Sony Subramanian; Dartois Veronique; Gruber Gerhard; Dick Thomas^*

来源：ACS Infectious Diseases, 2017, 3(11): 807-819.

DOI：10.1021/acsinfecdis.7b00079

• tuberculosis
• pyrazinamide
• pyrazinoic acid
• coenzyme A
• aspartate decarboxylase

Previously, we showed that a major in vitro and in vivo mechanism of resistance to pyrazinoic acid (POA), the bioactive component of the critical tuberculosis (TB) prodrug pyrazinamide (PZA), involves missense mutations in the aspartate decarboxylase PanD, an enzyme required for coenzyme A biosynthesis. What is the mechanism of action of POA? Upon demonstrating that treatment of M. bovis BCG with POA resulted in a depletion of intracellular coenzyme A and confirming that this POA-mediated depletion is prevented by either missense mutations in PanD or exogenous supplementation of pantothenate, we hypothesized that POA binds to PanD and that this binding blocks the biosynthetic pathway. Here, we confirm both hypotheses. First, metabolomic analyses showed that POA treatment resulted in a reduction of the concentrations of all coenzyme A precursors downstream of the PanD-mediated catalytic step. Second, using isothermal titration calorimetry, we established that POA, but not its prodrug PZA, binds to PanD. Binding was abolished for mutant PanD proteins. Taken together, these findings support a mechanism of action of POA in which the bioactive component of PZA inhibits coenzyme A biosynthesis via binding to aspartate decarboxylase PanD. Together with previous works, these results establish PanD as a genetically, metabolically, and biophysically validated target of PZA.

• 出版日期2017-11
• 单位rutgers; 南阳理工学院