Kinase experiment:

PARP activity is evaluated by utilizing commercially available recombinant bovine PARP-1 and mouse PARP-2. Briefly, the enzymatic reaction is carried out in 100 μL of 50 mM Tris-HCl (pH 8.0) containing 5 mM MgCl2, 2 mM dithiothreitol, 10 μg sonicated calf thymus DNA, 0.2 μCi [adenine-2,8-3H]NAD and recombinant enzyme PARP-1 or PARP-2 (0.03 U per sample). Different concentrations of the putative inhibitors are added, and the mixture is incubated for 1 h at 37℃. The reaction is terminated by adding 1 mL of 10% trichloroacetic acid (w/v) and centrifuged. Pellets are then washed twice with 1 mL of H2O and resuspended in 1 mL of 0.1 M NaOH. The radioactivity incorporated from [adenine-2,8-3H]NAD into proteins is evaluated by liquid scintillation spectrometry[2].

UPF 1069, a derivative of isoquinolinone, is a potent and selective inhibitor of poly-(ADP-ribose) polymerase 2 (PARP-2), with the value of 50% inhibition concentration IC₅₀of 0.3 μmol/L, that is capable of reducing PAR formation both in recombinant enzyme preparations and in nuclear extracts from PARP^-1-/-fibroblasts. Although its inhibition towards PARP-2 is most selective among other PARP-2 inhibitors, UPF 1069 also inhibits PARP-1 with a lesser potency (the value of IC₅₀of 8 μmol/L). Having been used to investigate the role of PARP-1 and PARP-2 in post-ischaemic brain damage, UPF 1069 enhances oxygen-glucose deprivation (OGD) injury in hippocampal slices.

Reference

[1].Moroni F, Formentini L, Gerace E, Camaioni E, Pellegrini-Giampietro DE, Chiarugi A, Pellicciari R. Selective PARP-2 inhibitors increase apoptosis in hippocampal slices but protect cortical cells in models of post-ischaemic brain damage. Br J Pharmacol. 2009;157(5):854-862