Effect of Drug-to-Protein\nReaction Kinetics on the\nResults of Thermal Proteome Profiling

In this Letter, a two-term formalism for constructing\nprotein solubility\ncurves in thermal proteome profiling (TPP) is considered, which takes\ninto account the efficiency of the drug–protein binding reaction.\nWhen the reaction is incomplete, this results in distortion of the\notherwise sigmoidal shape of the curve after drug treatment, which\nis often observed in experiments. This distortion may be significant\nenough to disqualify the corresponding protein from the list of drug\ntarget candidates, thus negatively affecting the results of TPP data\nanalysis. To further assist this analysis, we also developed the solubility\ncurve simulation software to visualize the discussed effect. Several\nexperimental data sets from recent TPP studies have been reprocessed,\nand we demonstrate in a few examples that the proposed two-term equation\nfits correctly the observed protein solubility curves with distorted\nshapes, also highlighting the previously unrecognized targets.