Smirnov A N, Kondrat'ev Ia Iu, Smirnova O V, Rozen V B
Probl Endokrinol (Mosk). 1978 Sep-Oct;24(5):79-85.
A study was made of some binding and physico-chemical properties of a special estrogen-binding protein of liver cytozol in sexually mature female and male guinea pigs following its partial purification by means of ammonium sulfate sedimentation, gelfiltration and ion-exchange chromatography. The given protein proved to bind estradiol (E2) with Ka of the 10(7) M-1 order and possessed a rather marked hormonal affinity specificity. Under unbalanced conditions its complexes with E2 were capable of rapid dissociation. Characteristics of the size of protein molecules were: molecular weight--about 60000, Stokes' radius--3.2 nm, sedimentation coefficient--4.6, friction coefficient ratio--1.18. Protein E2-binding activity was reversibly depressed in the presence of high salt concentrations, decreased in the presence of dithioerythritol and on heating at the temperature of over 50 degree C. The optimum E2 binding was observed at pH 7.3--7.7. There were no significant differences in the properties of protein from the liver of males and females. A conclusion was drawn on a close similarity between the given protein of guinea pigs and of a special estrogen-binding protein of the liver in male rats detected by the authors earlier.
对性成熟的雌性和雄性豚鼠肝脏胞质溶胶中的一种特殊雌激素结合蛋白进行了研究，该蛋白通过硫酸铵沉淀、凝胶过滤和离子交换色谱法进行部分纯化后，研究了其一些结合特性和物理化学性质。结果表明，该蛋白与雌二醇（E2）的结合常数Ka为10(7) M-1量级，具有相当明显的激素亲和力特异性。在非平衡条件下，其与E2的复合物能够快速解离。蛋白质分子大小的特征为：分子量约60000，斯托克斯半径3.2纳米，沉降系数4.6，摩擦系数比1.18。在高盐浓度存在下，蛋白质E2结合活性可逆性降低，在二硫苏糖醇存在下以及在50℃以上加热时降低。在pH 7.3 - 7.7时观察到最佳E2结合。雄性和雌性肝脏中蛋白质的性质没有显著差异。得出的结论是，豚鼠的这种蛋白质与作者之前在雄性大鼠肝脏中检测到的一种特殊雌激素结合蛋白非常相似。
