Selection of DNA-encoded chemical libraries against endogenous membrane proteins on live cells

Membrane proteins on the cell surface perform a myriad of biological functions; however, ligand discovery for membrane proteins is highly challenging, because a natural cellular environment is often necessary to maintain protein structure and function. DNA-encoded chemical libraries (DELs) have emerged as a powerful technology for ligand discovery, but they are mainly limited to purified proteins. Here we report a method that can specifically label membrane proteins with a DNA tag, and thereby enable target-specific DEL selections against endogenous membrane proteins on live cells without overexpression or any other genetic manipulation. We demonstrate the generality and performance of this method by screening a 30.42-million-compound DEL against the folate receptor, carbonic anhydrase 12 and the epidermal growth factor receptor on live cells, and identify and validate a series of novel ligands for these targets. Given the high therapeutic significance of membrane proteins and their intractability to traditional high-throughput screening approaches, this method has the potential to facilitate membrane-protein-based drug discovery by harnessing the power of DEL. A method to label membrane proteins with a DNA tag has been developed that enables the selection of DNA-encoded chemical libraries against endogenous membrane proteins on live cells. As a demonstration, a 30-million-compound DNA-encoded chemical library is screened against folate receptor, carbonic anhydrase 12 and epidermal growth factor receptor on live cells.

Automated summary

A method has been developed to label membrane proteins with a DNA tag, allowing for the selection of DNA-encoded chemical libraries against endogenous membrane proteins on live cells. Screening of a 30-million-compound DEL against folate receptor, carbonic anhydrase 12, and epidermal growth factor receptor on live cells demonstrated the versatility and efficacy of this method.