Amgen, Inc., 1201 Amgen Court West AW2/3152, Seattle, Washington 98119-3105, USA.
Biochemistry. 2010 May 11;49(18):3797-804. doi: 10.1021/bi1001147.
Stimulation of red cell production through agonism of the erythropoietin receptor (EpoR) has historically been accomplished through administration of erythropoietin (EPO), the native ligand. The short half-life of EPO has led to the development of a variety of other agonists, including antibodies. It is of considerable interest to understand how these agents might activate the EpoR and whether or not it is important to bind in a manner similar to the native ligand. The binding epitopes of a panel of eight agonistic, single-chain antibody (scFv-Fc) constructs were determined through scanning alanine mutagenesis as well as more limited arginine mutagenesis of the receptor. It was found that while some of these constructs bound to receptor epitopes shared by the ligand, others bound in completely unique ways. The use of a panel of agonists and scanning mutagenesis can define the critical binding regions for signaling; in the case of the EpoR, these regions were remarkably broad.
通过激动红细胞生成素受体 (EpoR) 来刺激红细胞生成，在历史上一直通过给予内源性配体促红细胞生成素 (EPO) 来实现。EPO 的半衰期短，导致了各种其他激动剂的开发，包括抗体。了解这些药物如何激活 EpoR 以及是否以类似于内源性配体的方式结合很重要。通过扫描丙氨酸突变以及对受体的更有限的精氨酸突变，确定了一组八种激动性单链抗体 (scFv-Fc) 构建体的结合表位。结果发现，虽然其中一些构建体与配体共享的受体表位结合，但其他构建体则以完全独特的方式结合。使用一组激动剂和扫描突变可以定义信号传导的关键结合区域；就 EpoR 而言，这些区域非常广泛。
