Identification of allosteric binding sites for PI3Kα oncogenic mutant specific inhibitor design

Publication date: Available online 16 January 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Michelle S. Miller, Sweta Maheshwari, Fiona M. McRobb, Kenneth W. Kinzler, L. Mario Amzel, Bert Vogelstein, Sandra B. Gabelli
PIK3CA, the gene that encodes the catalytic subunit of phosphatidylinositol 3-kinase α (PI3Kα), is frequently mutated in breast and other types of cancer. A specific inhibitor that targets the mutant forms of PI3Kα could maximize treatment efficiency while minimizing side-effects. Herein we describe the identification of novel binding pockets that may provide an opportunity for the design of mutant selective inhibitors. Using a fragment-based approach, we screened a library of 352 fragments (MW <300 Da) for binding to PI3Kα by X-ray crystallography. Five novel binding pockets were identified, each providing potential opportunities for inhibitor design. Of particular interest was a binding pocket near Glu542, which is located in one of the two most frequently mutated domains.

Graphical abstract

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