Seiki K, Imanishi Y, Haruki Y, Enomoto T
Endocrinol Jpn. 1979 Apr;26(2):159-65. doi: 10.1507/endocrj1954.26.159.
Sucrose density gradient ultracentrifugation and dextran-coated charcoal adsorption permitted us to characterize the estrogen-binding proteins in cytosols obtained from the thymus, spleen and mesenteric lymph node of the castrated male and female mice of C57BL strain. The thymic cytosol from both sexes incubated with 3H-estradiol-17 beta in the presence of excess unlabeled steroids showed a specific estrogenbinding 4 S protein with its binding capacity of 10(-14) moles/mg protein for males and 4 x 10(-15) moles/mg protein for females, respectively. The dissociation constant was of 4 x 10(-10) M for males and 3 x 10(-10) M for females, respectively. No specific binding was, however, found in the cytosols of the spleen and mesenteric lymph node. Steroid analysis by thin-layer chromatography of the thymic cytosols after incubation of them with 3H-estradiol-17 beta showed that a fair amount (around 60%) of radioactivity was from the undegradated radioactive steroid still bound to 4 S binder in both sexes. Enzyme study and heat experiment revealed that the estrogen specific 4 S binding component in the thymic cytosols bears at least protein in nature and is of heat-labile nature. These results strongly suggest that the thymus of the castrated mice contain a specific estrogen receptor, the nature of which is in part protein and heat-labile.
蔗糖密度梯度超速离心法和葡聚糖包被活性炭吸附法使我们能够对从C57BL品系阉割的雄性和雌性小鼠的胸腺、脾脏和肠系膜淋巴结获得的胞质溶胶中的雌激素结合蛋白进行表征。在过量未标记类固醇存在下，两性的胸腺胞质溶胶与³H-雌二醇-17β孵育，显示出一种特异性雌激素结合4S蛋白，其结合能力雄性为10⁻¹⁴摩尔/毫克蛋白，雌性为4×10⁻¹⁵摩尔/毫克蛋白。解离常数雄性为4×10⁻¹⁰M，雌性为3×10⁻¹⁰M。然而，在脾脏和肠系膜淋巴结的胞质溶胶中未发现特异性结合。将胸腺胞质溶胶与³H-雌二醇-17β孵育后，通过薄层色谱法进行类固醇分析表明，两性中相当数量（约60%）的放射性来自仍与4S结合剂结合的未降解放射性类固醇。酶学研究和热实验表明，胸腺胞质溶胶中的雌激素特异性4S结合成分至少在本质上是蛋白质，并且具有热不稳定的性质。这些结果有力地表明，阉割小鼠的胸腺含有一种特异性雌激素受体，其本质部分是蛋白质且热不稳定。
