VIB-VUB Center for Structural Biology, VIB, Pleinlaan 2, 1050, Brussels, Belgium.
Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.
Angew Chem Int Ed Engl. 2018 May 4;57(19):5292-5295. doi: 10.1002/anie.201712581. Epub 2018 Mar 30.
The conformational complexity of transmembrane signaling of G-protein-coupled receptors (GPCRs) is a central hurdle for the design of screens for receptor agonists. In their basal states, GPCRs have lower affinities for agonists compared to their G-protein-bound active state conformations. Moreover, different agonists can stabilize distinct active receptor conformations and do not uniformly activate all cellular signaling pathways linked to a given receptor (agonist bias). Comparative fragment screens were performed on a β -adrenoreceptor-nanobody fusion locked in its active-state conformation by a G-protein-mimicking nanobody, and the same receptor in its basal-state conformation. This simple biophysical assay allowed the identification and ranking of multiple novel agonists and permitted classification of the efficacy of each hit in agonist, antagonist, or inverse agonist categories, thereby opening doors to nanobody-enabled reverse pharmacology.
G 蛋白偶联受体 (GPCR) 的跨膜信号转导构象复杂性是设计受体激动剂筛选的主要障碍。在基础状态下，GPCR 对激动剂的亲和力低于其与 G 蛋白结合的活性状态构象。此外，不同的激动剂可以稳定不同的活性受体构象，并且不会均匀地激活与给定受体相关的所有细胞信号通路（激动剂偏向）。在通过模拟 G 蛋白的纳米体锁定在其活性状态构象的β-肾上腺素受体-纳米体融合物上，以及在其基础状态构象的相同受体上，进行了比较片段筛选。这种简单的生物物理测定法允许鉴定和对多种新型激动剂进行排序，并允许对每个激动剂、拮抗剂或反向激动剂类别的命中的功效进行分类，从而为基于纳米体的反向药理学开辟了道路。
