Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Science. 2010 Nov 19;330(6007):1091-5. doi: 10.1126/science.1197410.
Dopamine modulates movement, cognition, and emotion through activation of dopamine G protein-coupled receptors in the brain. The crystal structure of the human dopamine D3 receptor (D3R) in complex with the small molecule D2R/D3R-specific antagonist eticlopride reveals important features of the ligand binding pocket and extracellular loops. On the intracellular side of the receptor, a locked conformation of the ionic lock and two distinctly different conformations of intracellular loop 2 are observed. Docking of R-22, a D3R-selective antagonist, reveals an extracellular extension of the eticlopride binding site that comprises a second binding pocket for the aryl amide of R-22, which differs between the highly homologous D2R and D3R. This difference provides direction to the design of D3R-selective agents for treating drug abuse and other neuropsychiatric indications.
多巴胺通过大脑中多巴胺 G 蛋白偶联受体的激活来调节运动、认知和情绪。人源多巴胺 D3 受体（D3R）与小分子 D2R/D3R 特异性拮抗剂埃替利罗复合物的晶体结构揭示了配体结合口袋和细胞外环的重要特征。在受体的细胞内侧，观察到离子锁的锁定构象和细胞内环 2 的两种截然不同的构象。D3R 选择性拮抗剂 R-22 的对接揭示了埃替利罗结合位点的细胞外延伸，该延伸包含了 R-22 的芳酰胺的第二个结合口袋，该口袋在高度同源的 D2R 和 D3R 之间存在差异。这种差异为设计用于治疗药物滥用和其他神经精神疾病的 D3R 选择性药物提供了方向。
