A protein-targeting strategy used to develop a selective inhibitor of the E17K point mutation in the PH domain of Akt1

作者：Deyle Kaycie M; Farrow Blake; Hee Ying Qiao; Work Jeremy; Wong Michelle; Lai Bert; Umeda Aiko; Millward Steven W; Nag Arundhati; Das Samir; Heath James R^*

来源：Nature Chemistry, 2015, 7(5): 455-462.

DOI：10.1038/NCHEM.2223

Ligands that can bind selectively to proteins with single amino-acid point mutations offer the potential to detect or treat an abnormal protein in the presence of the wild type (WT). However, it is difficult to develop a selective ligand if the point mutation is not associated with an addressable location, such as a binding pocket. Here we report an all-chemical synthetic epitope-targeting strategy that we used to discover a 5-mer peptide with selectivity for the E17K-transforming point mutation in the pleckstrin homology domain of the Akt1 oncoprotein. A fragment of Akt1 that contained the E17K mutation and an I19[propargylglycine] substitution was synthesized to form an addressable synthetic epitope. Azide-presenting peptides that clicked covalently onto this alkyne-presenting epitope were selected from a library using in situ screening. One peptide exhibits a 10: 1 in vitro selectivity for the oncoprotein relative to the WT, with a similar selectivity in cells. This 5-mer peptide was expanded into a larger ligand that selectively blocks the E17K Akt1 interaction with its PIP3 (phosphatidylinositol ( 3,4,5)-trisphosphate) substrate.

• 出版日期2015-5