Cai Bo, El Daibani Amal, Bai Yuntian, Che Tao, Krusemark Casey J
Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907, United States.
Center for Clinical Pharmacology, Department of Anesthesiology, Washington University in St. Louis, St. Louis, Missouri 63110, United States.
JACS Au. 2023 Mar 22;3(4):1076-1088. doi: 10.1021/jacsau.2c00674. eCollection 2023 Apr 24.
G protein-coupled receptors (GPCRs) are the largest superfamily of human membrane target proteins for approved drugs. GPCR ligands can have a complex array of pharmacological activities. Among these activities, biased agonists have potential to serve as both chemical probes to understand specific aspects of receptor signaling and therapeutic leads with more specific, desired activity. Challenges exist, however, in the development of new biased activators due, in part, to the low throughput of traditional screening approaches. DNA-encoded chemical libraries (DELs) dramatically improve the throughput of drug discovery by allowing a collective selection, rather than discrete screening, of large compound libraries. The use of DELs has been largely limited to affinity-based selections against purified protein targets, which identify binders only. Herein, we report a split protein complementation approach that allows direct identification of DNA-linked molecules that induce the dimerization of two proteins. We used this selection with a DEL against opioid receptor GPCRs on living cells for the identification of small molecules that possess the specific function of activation of either β-arrestin or G protein signaling pathways. This approach was applied to δ-, μ-, and κ-opioid receptors and enabled the discovery of compound [66,66], a selective, G-protein-biased agonist of the κ-opioid receptor (EC = 100 nM, = 82%, G bias factor = 6.6). This approach should be generally applicable for the direct selection of chemical inducers of dimerization from DELs and expand the utility of DELs to enrich molecules with a specific and desired biochemical function.
G蛋白偶联受体（GPCRs）是获批药物的人类膜靶蛋白中最大的超家族。GPCR配体可具有一系列复杂的药理活性。在这些活性中，偏向激动剂有潜力作为化学探针来理解受体信号传导的特定方面，以及作为具有更特异性、所需活性的治疗先导物。然而，新型偏向激活剂的开发存在挑战，部分原因是传统筛选方法的通量较低。DNA编码化学文库（DELs）通过对大型化合物文库进行集体选择而非离散筛选，极大地提高了药物发现的通量。DELs的使用在很大程度上限于针对纯化蛋白靶点的基于亲和力的选择，这种选择仅能识别结合剂。在此，我们报告了一种分裂蛋白互补方法，该方法允许直接鉴定诱导两种蛋白二聚化的DNA连接分子。我们将这种选择方法与DELs结合，用于在活细胞上针对阿片受体GPCRs进行筛选，以鉴定具有激活β-抑制蛋白或G蛋白信号通路特定功能的小分子。这种方法应用于δ-、μ-和κ-阿片受体，并发现了化合物[66,66]，它是κ-阿片受体的一种选择性、偏向G蛋白的激动剂（EC = 100 nM， = 82%，G偏向因子 = 6.6）。这种方法通常应适用于从DELs中直接选择二聚化的化学诱导剂，并扩展DELs的效用，以富集具有特定和所需生化功能的分子。
