A Cyclic Tetrapeptide (“Cyclodal”) and Its Mirror-Image Isomer Are Both High-Affinity μ Opioid Receptor Antagonists
作者:Grazyna Weltrowska、Thi M.-D. Nguyen、Nga N. Chung、JodiAnne Wood、Xiaoyu Ma、Jason Guo、Brian C. Wilkes、Yang Ge、André Laferrière、Terence J. Coderre、Peter W. Schiller
DOI:10.1021/acs.jmedchem.6b01200
日期:2016.10.13
opioid receptor (MOR) agonist [Dmt1]DALDA (H-Dmt-d-Arg-Phe-Lys-NH2 (9; Dmt = 2′,6′-dimethyltyrosine) resulted in a highly active, selective MOR antagonist, c[-d-Arg-Phe-Lys-Dmt-] (1) (“cyclodal”), with subnanomolar binding affinity. A docking study of cyclodal using the crystal structure of MOR in the inactive form showed a unique binding mode with the two basic residues of the ligand forming salt
μ阿片受体激动剂[Dmt 1 ] DALDA(H-Dmt- d -Arg-Phe-Lys-NH 2(9 ; Dmt = 2',6'-二甲基酪氨酸)从头到尾环化导致一种具有高活性的选择性MOR拮抗剂c [ -d -Arg-Phe-Lys-Dmt-](1)(“环糊精”),具有亚纳摩尔结合亲和力。形式显示出独特的结合模式,配体的两个基本残基与Asp 127和Glu 229形成盐桥受体残基。静脉注射时,摆线针显示出较高的血浆稳定性,并能够穿过血脑屏障以逆转吗啡诱导的中央介导的镇痛作用。出乎意料的是,环化的c [-Arg- d -Phe- d -Lys- d -Dmt-](2)的镜像异构体(光学对映体)也被证明是具有1 nM结合亲和力的选择性MOR拮抗剂。因此,这两种化合物代表了镜像阿片受体配体的第一个实例,其两个光学对映体均具有高结合亲和力。灭环蛋白中Lys-Dmt肽键的还原产生了具有MOR激动剂活性的类似物c