Quantitative Validation and Application of the Photo-Cross-Linking Selection for Double-Stranded DNA-Encoded Libraries

The DNA-encoded compound library (DEL) technology has accelerated the target hits discovery in new drug development. While affinity-based DEL selection can distinguish high-affinity ligands, moderate-affinity ligands are also potential drug candidates with further modifications. Herein, we designed a photo-cross-linking selection method for DELs with double-stranded DNA (dsDELs) to screen moderate-affinity ligands. We constructed two photo-cross-linking libraries with linkers of different lengths that connect a diazirine group to the DNA encoded compound. The diazirine group can be activated by UV irradiation and thus bond with the target protein in a reachable distance. In the model selection, the feasibility of the photo-cross-linking screening system was verified by qPCR and NGS technology. Both high-affinity and moderate-affinity ligands were successfully selected from the libraries.