香港大学李笑宇团队报道了利用编码文库发现活细胞膜蛋白激动剂。相关研究成果发表在2024年8月22日出版的《美国化学会杂志》。

识别膜蛋白的生物活性配体是化学生物学中的一项重要任务。

该文中，研究人员报告了一种通过选择活细胞上的DNA编码文库（DEL）直接鉴定针对膜蛋白的小分子激动剂的方法。这种方法将细胞外配体结合与细胞内生化转化联系起来，从而将选择偏向于激动剂鉴定。研究人员用三种膜蛋白证明了该方法：表皮生长因子受体（EGFR）、血小板生成素受体（TPOR）和胰岛素受体（INSR）。

针对这些靶点选择了约3000万个和10.33亿个化合物DEL，并发现了具有亚纳米亲和力和低微摩尔细胞活性的新型激动剂。INSR激动剂可能通过与变构位点结合来激活受体，与胰岛素表现出明显的协同作用，并激活下游信号通路。值得注意的是，激动剂没有激活胰岛素样生长因子1受体（IGF-1R），这是一种高度同源的受体，其激活可能导致肿瘤进展。

总的来说，该项工作开发了一种在细胞表面进行“功能性”DEL选择的方法，并可能为膜蛋白激动剂的发现提供一种广泛适用的方法。

附：英文原文

Title: Agonist Discovery for Membrane Proteins on Live Cells by Using DNA-encoded Libraries

Author: Yiran Huang, Rui Hou, Fong Sang Lam, Yunxuan Jia, Yu Zhou, Xun He, Gang Li, Feng Xiong, Yan Cao, Dongyao Wang, Xiaoyu Li

Issue&Volume: August 22, 2024

Abstract: Identifying biologically active ligands for membrane proteins is an important task in chemical biology. We report an approach to directly identify small molecule agonists against membrane proteins by selecting DNA-encoded libraries (DELs) on live cells. This method connects extracellular ligand binding with intracellular biochemical transformation, thereby biasing the selection toward agonist identification. We have demonstrated the methodology with three membrane proteins: epidermal growth factor receptor (EGFR), thrombopoietin receptor (TPOR), and insulin receptor (INSR). A ～30 million and a 1.033 billion-compound DEL were selected against these targets, and novel agonists with subnanomolar affinity and low micromolar cellular activities have been discovered. The INSR agonists activated the receptor by possibly binding to an allosteric site, exhibited clear synergistic effects with insulin, and activated the downstream signaling pathways. Notably, the agonists did not activate the insulin-like growth factor 1 receptor (IGF-1R), a highly homologous receptor whose activation may lead to tumor progression. Collectively, this work has developed an approach toward “functional” DEL selections on the cell surface and may provide a widely applicable method for agonist discovery for membrane proteins.

DOI: 10.1021/jacs.4c08624

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c08624