FIG. 2.
Enzyme mode of inhibition for compound 1. The activity of H. influenzae LigA was measured using a FRET assay in the presence of rising concentrations of compound 1 (0 to 2.6 μM) and NAD+ (0.5 to 3.5 μM), with a fixed concentration (60 nM) of the nicked DNA substrate. As represented in the double-reciprocal plot, the resulting data are consistent with competitive binding between compound 1 and NAD+. The apparent Ki for compound 1 was determined to be 110 nM by nonlinear regression analysis of the data.