Adenosine Kinase of T. b. rhodesiense Identified as the Putative Target of 4-[5-(4-phenoxyphenyl)-2H-pyrazol-3-yl]morpholine Using Chemical Proteomics
Figure 4
Specific binding of compound 1 to TbrAK measured by ITC.
The top panel shows heat signals upon 27 injections of compound 1 (trace I) or control compound 5 (trace II) into the sample cell containing 7 µM TbrAK. The binding isotherm obtained by integration and normalization of the raw data and by correction for the heat of ligand dilution is shown on the lower panel. The solid line represents the non-linear least square fit based on a two-sites non-interacting binding model. Compound 1 binds to TbrAK via a high affinity binding site with a KD of 75±20 nM and a ΔHbind of −3.05±0.77 kcal/mol, and a low affinity site exhibiting a KD of 497±34 nM and a ΔHbind of −1.13±0.24 kcal/mol. No specific heat release was shown for the negative control (trace II). The mean of three independent experiments are reported.