Figure 3.
Results from the screen of three National Cancer Institute libraries. A scatter plot of the relative inhibition (%) effected by 2180 compounds combined from three NCI libraries against RecA using the phosphomolybdate blue ATPase assay. Reactions proceeded for 35 min at 37 °C and contained RecA (0.5 μM), poly(dT) (5 μM-nts), ATP (0.75 mM), and assessed compounds (final concentration 17 μM). There were seven primary hits above a threshold of 50% inhibition. The structures of three confirmed hits sharing a similar scaffold from the National Cancer Institute screen are depicted at right. The IC50 values characterizing the three hits ranged from 4 to 6 μM.