CHARACTERIZATION OF R5020 AND RU486 BINDING TO PROGESTERONE-RECEPTOR FROM CALF UTERUS
CHARACTERIZATION OF R5020 AND RU486 BINDING TO PROGESTERONE-RECEPTOR FROM CALF UTERUS
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DOI：
10.1021/bi00410a014
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发表时间：
1988-05-17
期刊：
影响因子：
2.9
通讯作者：
MOUDGIL, VK
中科院分区：
文献类型：
--
作者：
HURD, C;MOUDGIL, VK
我们已经检查并比较了孕酮激动剂R5020 [普罗美孕酮，17，21-二甲基孕甾-4，9（10）-二烯-3，20-二酮]和孕酮拮抗剂RU 486 [米非司酮，17 β-二氢孕酮]的结合特性。羟基-11 β- [4-（二甲氨基）苯基]-17 α-（丙-1-炔基）-雌甾-4，9-二烯-3-酮]。两种类固醇均以高亲和力结合胞质溶胶大分子，R5020和RU 486结合的Kd值分别为5.6和3.6 nM。甾族化合物与大分子的结合在4.0 ℃下是快速的。C，显示[3 H]孕酮在1-2小时以及[3 H]R5020和[3 H] RU 486在2-4小时的结合位点饱和。添加甘油和甘油的胞质溶胶增加的程度[3 H]R5020的结合。[3 H] RU 486结合的程度保持不变的存在下，甘油，而有抑制作用。钼酸盐单独或与甘油组合使[3 H]R5020-和[3 H] RU 486-受体复合物稳定在37 ℃。C.虽然[3 H] RU 486与胞质大分子的结合速率比[3 H]R5020慢，但其从配体-大分子复合物中的解离明显慢于[3 H]R5020。竞争性类固醇结合分析显示，[3 H]孕酮、[3 H]R5020和[3 H] RU 486在子宫胞质溶胶中的相同位点完成，表明所有三种结合孕酮受体（PR）。沉降速率分析表明，这两种类固醇结合到一个分子中的8 S区域的沉积物。过量放射惰性孕酮、RU 486或R5020可消除8 S [3 H]R5020和[3 H] RU 486峰。这项研究的结果表明，虽然有一些差异，它们与PR的相互作用的性质，R5020和RU 486结合到相同的8 S受体在小牛子宫胞质溶胶。
We have examined and compared the binding characteristics of the progesterone agonist R5020 [promegestone, 17,21-dimethylpregna-4,9(10)-diene-3,20-dione] and the progesterone antagonist RU486 [mifepristone, 17.beta.-hydroxy-11.beta.-[4-(dimethylamino)phenyl]-17.alpha.-(prop-1-ynyl)-estra-4,9-dien-3-one] in calf uterine cytosol. Both steroids bound cytosol macromolecule(s) with high affinity, exhibiting Kd values of 5.6 and 3.6 nM for R5020 and RU486 binding, respectively. The binding of the steroids to the macromolecule(s) was rapid at 4.degree. C, showing saturation of binding sites at 1-2 h for [3H]progesterone and 2-4 h for both [3H]R5020 and [3H]RU486. Addition of molybdate and glycerol to cytosol increased the extent of [3H]R5020 binding. The extent of [3H]RU486 binding remained unchanged in the presence of molybdate, whereas glycerol had an inhibitory effect. Molybdate alone or in combination with glycerol stabilized the [3H]R5020- and [3H]RU486-receptor complexes at 37.degree. C. Although the rate of association of [3H]RU486 with the cytosolic macromolecule was slower than that of [3H]R5020, its dissociation from the ligand-macromolecule complex was significantly slower than [3H]R5020. Competitive steroid binding analysis revealed that [3H]progesterone, [3H]R5020, and [3H]RU486 complete for the same site(s) in the uterine cytosol, suggesting that all three bind to the progesterone receptor (PR). Sedimentation rate analysis showed that both steroids were bound to a molecule that sediments in the 8S region. The 8S [3H]R5020 and [3H]RU486 peaks were abolished by excess radioinert progesterone, RU486, or R5020. The results of this study suggest that, although there are some differences in the nature of their interaction with the PR, both R5020 and RU486 bind to the same 8S receptor in calf uterine cytosol.