Inhibition of PARP-3 and PARP-1 activity by various inhibitors. A, shown is the dose-dependent inactivation of auto-ADP-ribosylation of PARP-3 and PARP-1 by KU0058948. B, 250 nm PARP-3 or 10 nm PARP-1 was incubated with 25 μm Bio-NAD+ and different concentrations of various inhibitors for 5 min. PARP-1 samples were supplemented with activated DNA. 4-ANI, 4-amino-1,8-naphthalimide; DIQ, 1,5-dihydroisoquinoline; NAP, 1,8-naphthalimide; 3-ABA, 3-aminobenzamide.