Identifying the proteins to which small-molecule probes and drugs bind in cells | CU Experts

; Most small-molecule probes and drugs alter cell circuitry by interacting with 1 or more proteins. A complete understanding of the interacting proteins and their associated protein complexes, whether the compounds are discovered by cell-based phenotypic or target-based screens, is extremely rare. Such a capability is expected to be highly illuminating—providing strong clues to the mechanisms used by small-molecules to achieve their recognized actions; and; suggesting potential unrecognized actions. We describe a powerful method combining quantitative proteomics (SILAC) with affinity enrichment to provide unbiased, robust and comprehensive identification of the proteins that bind to small-molecule probes and drugs. The method is scalable and general, requiring little optimization across different compound classes, and has already had a transformative effect on our studies of small-molecule probes. Here, we describe in full detail the application of the method to identify targets of kinase inhibitors and immunophilin binders.;

Ong S-E; Schenone M; Margolin AA; Li X; Do K; Doud MK; Mani DR; Kuai L; Wang X; Wood JL

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