Jie Li; Juan Kong; Guang Yang; Hongtao Xu; Peixiang Ma
Bio-101, 2020, e1010829
https://doi.org/10.21769/BioProtoc.1010829

Abstract

The DNA-encoded compound library (DEL) is a giant compound library containing millions or even hundreds of millions of specific DNA tags. Sequencing technology enables high-throughput decoding of screening information (Brenner and Lerner, 1992; Ma et al., 2019). We successfully constructed the first natural product-based DNA-encoded compound library (nDEL) using photocrosslinking technology and click chemistry. We screened against the target protein PARP1 (polyadenosine diphosphate ribose polymerase-1) and obtained a small molecule inhibitor - luteolin (Luteolin). Once the DNA in the cell is damaged by single-strand break, the DNA-binding domain of PARP1 protein can quickly bind to the damage site, and the catalytic domain at the C-terminal catalyzes the decomposition of NAD+ into ADP ribose and nicotinamide, and then uses ADP ribose as a substrate. Long-chain modification of polyadenosine diphosphate ribose (Poly [ADP-ribose], PAR) on residues such as glutamic acid and aspartic acid of itself and other proteins, recruiting other proteins to participate in important functions such as DNA damage repair . In order to further explore the ability of luteolin to inhibit the activity of PARP1 in cells, we used high-content imaging technology to detect the generation of poly-ADP-ribose PAR in cells after luteolin treatment (Yuan et al., 2017; Li et al., 2020).