Properties of the cytoplasmic progestin-binding protein in the rabbit uterus.
Properties of the cytoplasmic progestin-binding protein in the rabbit uterus.
复制标题
兔子宫中细胞质孕激素结合蛋白的特性。
DOI：
10.1210/endo-101-6-1850
复制
发表时间：
1977
期刊：
影响因子：
4.8
通讯作者：
J. Raynaud
中科院分区：
文献类型：
--
作者：
D. Philibert;T. Ojasoo;J. Raynaud
使用标记为高比活性的高效的孕甾蛋白R5020（17，21-二甲基-19-去甲-4，9-孕甾二烯-3，20-二酮），在兔子宫胞质溶胶上开发了用于测量总细胞质孕甾蛋白结合位点的交换测定法。这种化合物与孕酮相比有几个优点：它不被血浆皮质类固醇结合球蛋白结合;它对孕酮受体具有高亲和力;它与受体的结合速度几乎与孕酮一样快，但形成的复合物解离速度慢8倍;它的结合不会被缺乏孕激素活性的化合物（雌激素，睾酮，地塞米松，醛固酮）取代超过2%。结合内源性孕酮交换氚R 5020在与受体稳定性兼容的时间。在0 ℃时，填充位点的完全交换在不到4小时内发生;在此温度下，R5020-受体复合物至少稳定28小时. R5020-受体复合物的构象进行了研究，在蔗糖密度梯度在各种实验条件下。与孕酮不同，在处死前1小时注射示踪剂[3 H]R 5020的家兔子宫胞液中可检测到7S峰。
An exchange assay for the measurement of total cytoplasmic progestin binding sites has been developed on rabbit uterine cytosol using the highly potent progestin, R5020 (17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione) labelled to a high specific activity. This compound has several advantages over progesterone: it is not bound by plasma corticosteroid binding globulin; it has high affinity for the progestin receptor; it binds virtually as fast as progesterone to the receptor, but the complex formed dissociated 8 times slower; its binding is not displaced by more than 2% by compounds devoid of progestational activity (estrogens, testosterone, dexamethasone, aldosterone). Bound endogenous progesterone was exchanged by tritiated R 5020 in a time compatible with receptor stability. At 0 C, total exchange of filled sites occurred in less than 4 h; at this temperature the R 5020-receptor complex was stable for at least 28 h. The conformation of the R 5020-receptor complex was investigated in sucrose density gradients under various experimental conditions. Unlike progesterone, it was possible to detect a 7S peak in uterine cytosol obtained from rabbits injected with a tracer dose of [3H]R 5020 1 h prior to sacrifice.