Reinecke, Maria Ruprecht, Benjamin Poser, Sandra Wiechmann, Svenja Wilhelm, Mathias Heinzlmeir, Stephanie Kuster, Bernhard Médard, Guillaume Chemoproteomic Selectivity Profiling of PIKK and PI3K Kinase Inhibitors Chemical proteomic approaches utilizing immobilized, broad-selective kinase inhibitors (Kinobeads) have proven valuable for the elucidation of a compound’s target profile under close-to-physiological conditions and often revealed potentially synergistic or toxic off-targets. Current Kinobeads enrich more than 300 native protein kinases from cell line or tissue lysates but do not systematically cover phosphatidylinositol 3-kinases (PI3Ks) and phosphatidylinositol 3-kinase-related kinases (PIKKs). Some PIKKs and PI3Ks show aberrant activation in many human diseases and are indeed validated drug targets. Here, we report the development of a novel version of Kinobeads that extends kinome coverage to these proteins. This is achieved by inclusion of two affinity probes derived from the clinical PI3K/MTOR inhibitors Omipalisib and BGT226. We demonstrate the utility of the new affinity matrix by the profiling of 13 clinical and preclinical PIKK/PI3K inhibitors. The large discrepancies between the PI3K affinity values obtained and reported results from recombinant assays led us to perform a phosphoproteomic experiment showing that the chemoproteomic assay is the better approximation of PI3K inhibitor action <i>in cellulo</i>. The results further show that NVP-BEZ235 is not a PI3K inhibitor. Surprisingly, the designated ATM inhibitor CP466722 was found to bind strongly to ALK2, identifying a new chemotype for drug discovery to treat <i>fibrodysplasia ossificans progressiva</i>. novel version;drug targets;Chemoproteomic Selectivity Profiling;Current Kinobeads;ATM inhibitor CP 466722;PIKK;drug discovery;PI 3K inhibitors Omipalisib;chemoproteomic assay;ALK;PI 3K inhibitor action;kinome coverage;cell line;phosphatidylinositol 3- kinases;protein kinases;affinity matrix;NVP-BEZ 235;close-to-physiological conditions;phosphoproteomic experiment;PI 3K inhibitor;PI 3K Kinase Inhibitors Chemical proteomic approaches;broad-selective kinase inhibitors;BGT 226.;PI 3K affinity values;phosphatidylinositol 3- kinase-related kinases;PI 3Ks show;affinity probes;tissue lysates;PI 3Ks;fibrodysplasia ossificans progressiva 2019-03-22
    https://acs.figshare.com/articles/dataset/Chemoproteomic_Selectivity_Profiling_of_PIKK_and_PI3K_Kinase_Inhibitors/7946564
10.1021/acschembio.8b01020.s004