Automated screening for small organic ligands using DNA-encoded chemical libraries

• Published in: Nature protocols Vol. 11; no. 4; pp. 764 - 780
• Main Authors: Decurtins, Willy, Wichert, Moreno, Franzini, Raphael M, Buller, Fabian, Stravs, Michael A, Zhang, Yixin, Neri, Dario, Scheuermann, Jörg
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.04.2016; Nature Publishing Group
• Subjects: 631/154/1435; 631/1647/514/2254; 631/92/605; Analytical Chemistry; Binders; Biological Techniques; Computational Biology/Bioinformatics; Deoxyribonucleic acid; DNA; DNA Adducts - analysis; DNA sequencing; High-Throughput Nucleotide Sequencing; Life Sciences; Ligands; Mass Screening - methods; Medical screening; Microarrays; Nucleotide sequencing; Observations; Oligonucleotides - chemistry; Oligonucleotides - genetics; Organic Chemistry; Organic compounds; Physiological aspects; Protein Binding; protocol; Small Molecule Libraries; Technology application
• ISSN: 1754-2189; 1750-2799
• DOI: 10.1038/nprot.2016.039

This protocol describes an approach for screening DNA-encoded chemical libraries (DECLs) to identify molecules that bind to proteins of interest. After isolating binding library members, DNA barcodes are amplified and identified by high-throughput sequencing. DNA-encoded chemical libraries (DECLs) are collections of organic compounds that are individually linked to different oligonucleotides, serving as amplifiable identification barcodes. As all compounds in the library can be identified by their DNA tags, they can be mixed and used in affinity-capture experiments on target proteins of interest. In this protocol, we describe the screening process that allows the identification of the few binding molecules within the multiplicity of library members. First, the automated affinity selection process physically isolates binding library members. Second, the DNA codes of the isolated binders are PCR-amplified and subjected to high-throughput DNA sequencing. Third, the obtained sequencing data are evaluated using a C++ program and the results are displayed using MATLAB software. The resulting selection fingerprints facilitate the discrimination of binding from nonbinding library members. The described procedures allow the identification of small organic ligands to biological targets from a DECL within 10 d.