Figure 3
EGCG inhibited PARP16 activity in vitro. (a) Chemical structures of ECG and its analog EGCG. (b) Binding curves of surface immobilized ECG and EGCG with flowing PARP16 at respective concentrations of 208, 84 and 42 nM. Vertical lines marked the starts of association and dissociation phases of the binding event. The dash lines were global fits to a Langmuir reaction model with the global fitting parameters listed at the bottom of the curves. (c) Concentration-dependent activity tests of ECG and EGCG against PARP16, which were detected by western blot with Streptavidin-HRP after reactions. The concentrations of ECG and EGCG in the experiments were from 10 to 200 μM. (d) The IC50 values were determined from dose–response curves using eight concentrations of each compound in triplicate based on ELISA assay. Curves were fitted to data points using nonlinear regression analysis and IC50 values were interpolated from the resulting curves using Graphpad prism 5 software. Data were shown as means±S.D. for the independent experiments.
