Covalent labeling of G protein-coupled receptors (GPCRs) by small molecules is a powerful approach to understand binding modes, mechanism of action, pharmacology, and even facilitate structure elucidation. We report the first covalent positive allosteric modulator (PAM) for a class C GPCR, the mGlu₂ receptor. Three putatively covalent mGlu₂ PAMs were designed and synthesized. Pharmacological characterization identified 2 to bind the receptor covalently. Computational modeling combined with receptor mutagenesis revealed T791^7.29×30 as the likely position of covalent interaction. We show how this covalent ligand can be used to characterize the PAM binding mode and that it is a valuable tool compound in studying receptor function and binding kinetics. Our findings advance the understanding of the mGlu₂ PAM interaction and suggest that 2 is a valuable probe for further structural and chemical biology approaches.

中文翻译：

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代谢型谷氨酸受体的共价变构探针2：设计，合成和药理学表征。

用小分子共价标记G蛋白偶联受体（GPCR）是了解结合模式，作用机理，药理作用甚至促进结构阐明的有力方法。我们报告的第一个共价阳性变构调节剂（PAM）为C类GPCR，mGlu ₂受体。设计并合成了三个推定共价的mGlu ₂ PAM。药理学特征鉴定为2与受体共价结合。计算模型结合受体诱变显示T791 ^7.29×30作为共价相互作用的可能位置。我们展示了这种共价配体如何用于表征PAM结合模式，并且它是研究受体功能和结合动力学的有价值的工具化合物。我们的发现提高了对mGlu ₂ PAM相互作用的理解，并表明2是进一步的结构和化学生物学方法的有价值的探针。