Recent Advances in GPCR Ligand Discovery Using DNA-Encoded Library Technology: From Affinity Binding to Functional Bias and Allosteric Modulation

DNA-encoded library (DEL) technology has emerged as a transformative platform for the discovery of bioactive small molecules against challenging therapeutic targets including G protein-coupled receptors (GPCRs). As a clinically pivotal class of membrane-bound targets, GPCRs pose inherent challenges in the discovery of novel ligands. This Microperspective highlights recent methodological advances (2015–2026) that enable DEL selections against GPCRs, thereby facilitating the identification of diverse ligand modalities, including agonists, antagonists, allosteric modulators, and biased ligands. Furthermore, we discuss current challenges and future directions in the application of DEL technology to GPCR drug discovery, with a specific emphasis on opportunities in receptor stabilization, selection strategy design, and computational method development.