Quantitative Assessment of Affinity Selection Performance by Using DNA-Encoded Chemical Libraries.

Area of Science:

• Chemical Biology
• Drug Discovery
• Molecular Biology

Background:

• DNA-encoded chemical libraries (DELs) are crucial for identifying ligands against protein targets.
• DEL screening involves affinity capture, PCR amplification, and DNA sequencing.
• The efficiency of individual DEL selection steps remains under-investigated.

Purpose of the Study:

• To quantitatively analyze the performance of affinity capture and selection steps in DEL screening.
• To evaluate the impact of input copy numbers on selection efficiency.
• To assess ligand recovery and selectivity using carbonic anhydrase IX as a model target.

Main Methods:

• Quantitative PCR (qPCR) to assess recovery and selectivity on various solid supports.
• Analysis of DNA sequencing data to evaluate individual ligand performance within a large library.
• Utilized three ligands with varying affinities to carbonic anhydrase IX.

Main Results:

• Affinity capture procedures were evaluated for recovery and selectivity on different solid-phase supports.
• Selection procedures are efficient for ligands with sub-micromolar dissociation constants.
• Selection performance drastically drops when input is 10^4 copies per library member.

Conclusions:

• Quantitative analysis provides insights into DEL selection step performance.
• DEL screening is effective for high-affinity ligands, but sensitive to input quantity.
• Optimizing input copy numbers is critical for successful DEL screening.