Alix I. Chan; Lynn M. McGregor; Tara Jain; David R. Liu
J. Am. Chem. Soc., 2017, 139, 30, 10192-10195
https://doi.org/10.1021/jacs.7b04880

Abstract

We previously reported interaction determination using unpurified proteins (IDUP), a method to selectively amplify DNA sequences encoding ligand:target pairs from a mixture of DNA-linked small molecules and unpurified protein targets in cell lysates. In this study we applied IDUP to libraries of DNA-encoded bioactive compounds and DNA-tagged human kinases to identify ligand:protein binding partners out of 32,096 possible combinations in a single solution-phase library × library experiment. The results recapitulated known small molecule:protein interactions and also revealed that ethacrynic acid is a novel ligand and inhibitor of MAP2K6 kinase. Ethacrynic acid inhibits MAP2K6 in part through alkylation of a non-conserved cysteine residue. This work validates the ability of IDUP to discover ligands for proteins of biomedical relevance.