Figure 7.

Concentration-dependent inhibition of M. tuberculosis PanD by POA but not by PZA or nicotinamide. The rightmost lane is a ¹⁴C-aspartic acid control without PanD or POA addition. (A) POA at 25, 50, or 100 µg/mL significantly inhibited the enzymatic activity of both wild-type and M117I PanD in a concentration-dependent manner as shown by the reduced conversion of aspartate (Asp) to β-alanine (β-Ala). At 200 µg/mL, POA completely inhibited the enzymatic activity of wild-type PanD (panels B and C, first lane from left). In contrast, neither PZA as a prodrug (B) nor nicotinamide (NIC) (C) as a structural analog control at 100 and 200 µg/mL had an apparent effect on PanD's enzymatic activity.