Progesterone receptors of chick oviduct. Steroid-binding "subunit" formed with divalent cations.
Progesterone receptors of chick oviduct. Steroid-binding "subunit" formed with divalent cations.
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鸡输卵管的孕酮受体。
DOI：
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发表时间：
1974
影响因子：
4.8
通讯作者：
L. Hoffman
中科院分区：
文献类型：
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作者：
M. R. Sherman;S. B. Atienza;J. R. Shansky;L. Hoffman
雌激素处理的鸡输卵管孕酮受体在几种二价阳离子存在下，释放一个沉降系数为2.6S，斯托克斯半径为21 A，表观分子量约为20，000的“亚单位”。结合类固醇的活性炭-葡聚糖分析揭示了与完整受体相同的“亚基”亲和力顺序：孕酮（Kd = 4 × 10-10 m）g脱氧皮质酮g睾酮g皮质酮g 17β-雌二醇g皮质醇。在所测试的阳离子中，形成“亚基”的有效性顺序为Ca 2 + g Mn 2 + g Sr 2 + g Ba 2+。Mg 2+是无效的。“亚基”可以通过CaCl 2处理通过密度梯度离心（4和5S组分）、等电聚焦或聚阳离子沉淀部分纯化的受体来获得。“亚基”在类固醇或二异丙基氟磷酸（蛋白酶抑制剂）存在或不存在下形成。这些观察结果和45 Ca 2+结合的初步研究结果与Ca 2+和类似离子与受体复合物组分的直接相互作用一致。
Abstract In the presence of several divalent cations, progesterone receptors of estrogen-treated chick oviducts release a "sub-unit" characterized by a sedimentation coefficient of 2.6 S, Stokes radius of 21 A, and apparent molecular weight of about 20,000. Charcoal-dextran assay of bound steroid reveals the same order of affinities for the "subunit" as for intact receptors: progesterone (Kd ≃ 4 x 10-10 m) g deoxycorticosterone g testosterone g corticosterone g 17β-estradiol g cortisol. Among the cations tested, the order of effectiveness for "subunit" formation is Ca2+ g Mn2+ ≃ Sr2+ g Ba2+. Mg2+ is ineffective. "Subunit" can be obtained by CaCl2 treatment of receptors partially purified by density gradient centrifugation (4 and 5 S components), isoelectric focusing, or polycation precipitation. "Subunit" is formed in the presence or absence of steroid or of diisopropylfluorophosphate, a protease inhibitor. These observations and the results of preliminary studies of 45Ca2+-binding are consistent with a direct interaction of Ca2+ and similar ions with a component of the receptor complex.