Crystal Structures of PI3Kα Complexed with PI103 and Its Derivatives: New Directions for Inhibitors Design
- ACS Med Chem Lett. 2013 Dec 10;5(2):138-42. doi: 10.1021/ml400378e.
- 1. Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai JiaoTong University, School of Medicine , Shanghai 200025, China.
- 2. Division of Anti-tumor Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences , Shanghai 201203, China.
- 3. Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS) , Guangdong, Shenzhen 518055, China.
The phosphatidylinositol 3-kinase (PI3K) signaling pathway plays important roles in cell proliferation, growth, and survival. Hyperactivated PI3K is frequently found in a wide variety of human cancers, validating it as a promising target for Cancer therapy. We determined the crystal structure of the human PI3Kα-PI103 complex to unravel molecular interactions. Based on the structure, substitution at the R1 position of the phenol portion of PI103 was demonstrated to improve binding affinity via forming a new H-bond with Lys802 at the bottom of the ATP catalytic site. Interestingly, the crystal structure of the PI3Kα-9d complex revealed that the flexibility of Lys802 can also induce additional space at the catalytic site for further modification. Thus, these crystal structures provide a molecular basis for the strong and specific interactions and demonstrate the important role of Lys802 in the design of novel PI3Kα inhibitors.