在μ-阿片类受体激活过程中形状变化的传播
Rémy Sounier1, Camille Mas1, Jan Steyaert2,3
1Institut de Genomique Fonctionnelle, CNRS UMR-5203 INSERM U1191, University of Montpellier, F-34000 Montpellier, France.
Nature
|August 7, 2015
概括
这项研究揭示了片受体 (μOR) 的激活方式. 仅激素的结合就会导致轻微的变化,而主要的结构变化需要G蛋白的相互作用,这表明最初的G蛋白合涉及其他受体区域.
科学领域:
- 生物化学
- 分子生物学
- 药理学
背景情况:
- 类受体 (μOR) 是治疗疼痛的关键点,由多种激动剂激活.
- 最近的结构数据显示不活跃和活跃的μOR状态,但动态激活途径尚不清楚.
研究的目的:
- 通过使用溶液状态的NMR来研究μOR在激活过程中的动态构造变化.
- 阐明将激动剂与G蛋白结合联系起来的事件序列.
主要方法:
- 使用溶液状态核磁共振 (NMR) 光谱.
- 在模仿膜的环境中检查纯化的小鼠μOR.
- 测试了没有配体的受体,单独的激动剂 (BU72),以及具有G蛋白模拟纳米体的激动剂.
主要成果:
- 完全的G蛋白参与需要激动剂和G蛋白模拟剂,这表明结合部位与TM5/TM6之间的合力较弱.
- 单独激素结合导致细胞内循环1和螺旋8的显著变化,而不是TM5/TM6.
- 在没有G蛋白仿真体的情况下,跨膜片段5和6 (TM5/TM6) 显示出最小的形状变化.
结论:
- 最初的μOR激活涉及细胞内循环1和螺旋8,可能会调解G蛋白的特异性.
- 跨膜段TM5和TM6在G蛋白复合体形成过程中参与.
- 这表明μORs的多步激活机制与简单的直接合不同.
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