Chemoproteomic Selectivity Profiling of PIKK and PI3K Kinase Inhibitors
datasetposted on 22.03.2019, 00:00 by Maria Reinecke, Benjamin Ruprecht, Sandra Poser, Svenja Wiechmann, Mathias Wilhelm, Stephanie Heinzlmeir, Bernhard Kuster, Guillaume Médard
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 in cellulo. 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 fibrodysplasia ossificans progressiva.
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novel versiondrug targetsChemoproteomic Selectivity ProfilingCurrent KinobeadsATM inhibitor CP 466722PIKKdrug discoveryPI 3K inhibitors Omipalisibchemoproteomic assayALKPI 3K inhibitor actionkinome coveragecell linephosphatidylinositol 3- kinasesprotein kinasesaffinity matrixNVP-BEZ 235close-to-physiological conditionsphosphoproteomic experimentPI 3K inhibitorPI 3K Kinase Inhibitors Chemical proteomic approachesbroad-selective kinase inhibitorsBGT 226.PI 3K affinity valuesphosphatidylinositol 3- kinase-related kinasesPI 3Ks showaffinity probestissue lysatesPI 3Ksfibrodysplasia ossificans progressiva