Figure 4
(A) Relaxation-edited NMR for compound 9, showing the largest reduction in peak height for the quinoxaline protons (boxed), indicating that the majority of binding can be attributed to the quinoxaline moiety. (B) Protein-observed NMR for TNKS2 ARC4. Example area of superimposed 1H-15N HSQC NMR spectra, showing the chemical shift perturbations (CSPs) upon TBM peptide or compound 9 titration. (C) Kd estimate of compound 9 by plotting the CSPs of peaks that moved in a concentration-dependent manner. (D) ITC for the titration of compound 9 (5 mM) into TNKS2 ARC4 (200 μM). The Kd for compound 9 was calculated to be 1200 ± 380 μM; the stoichiometry of compound 9:TNKS2 ARC4 was 1.1 (global analysis of n = 5 independent experiments). See Supplementary Fig. 5 for an example titration of compound 9 into buffer. (E) Compound 9 binding to TNKS and TNKS2 ARCs was assessed by relaxation-edited NMR. Total reductions in peak area upon ARC addition are indicated.
