抗激素结合的腺A2A受体结构揭示了GPCR激活的共同特征
Guillaume Lebon1, Tony Warne, Patricia C Edwards
1MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK.
Nature
|May 20, 2011
概括
这项研究揭示了腺受体 (A2A R) 如何结合激动剂,显示与β-腺受体的结构相似之处. 这些发现为G蛋白结合受体 (GPCRs) 的常见激活机制提供了洞察力.
科学领域:
- 结构生物学 结构生物学
- 药理学 药理学是指药理学的学科.
- 生物化学 生物化学
背景情况:
- 与G蛋白结合受体 (GPCRs) 类似于腺受体和β-腺受体,它们具有共同的结构动机,并在激素结合时激活细胞内G蛋白.
- 之前对β-上腺受体的研究表明,跨膜5区域残留在激素特异性结合和受体激活中的重要性.
研究的目的:
- 阐明人类腺氨酸A2A受体 (A2A R) 中激素结合和激活的结构基础.
- 将A2A R的激活机制与β-腺受体的激活机制进行比较,以确定共同的GPCR激活特征.
主要方法:
- 确定了热稳定的人类腺A2A受体 (A2A R-GL31) 的两个晶体结构,与其内源性agonist腺和合成agonist (NECA) 复合.
- 分析了联结相互作用,重点关注激素替代剂 (腺素和核糖) 和受体残留物的作用.
- 将获得的A2A R结构与现有的β-上腺受体结构进行比较.
主要成果:
- A2A R结构代表了不活跃和活跃构造之间的中间状态,其中G蛋白结合部位被跨膜螺旋6部分封闭.
- 激动剂结合涉及腺素部分与受体残留的相互作用,类似于逆激动剂结合,而核糖组在口袋深处形成极性和非极性接触.
- 反向激动剂ZM241385在超膜螺旋5中的结构变化受到固体阻碍,解释了它的反向激动作用.
结论:
- 激动剂与A2A R的结合涉及特定的相互作用,启动受体激活,不同于逆激动剂结合.
- 结构性比较表明,通过3,5和7螺旋向内移动的结合口袋的体诱导的收缩是GPCR激活的保存机制.
- 这些发现为了解GPCR激活和设计针对腺受体的新疗法提供了结构性框架.
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