摘要
Immature rat testes contain a specific binding protein for testosterone (T) and 5α-dihyrotestosterone (DHT) with physico-chemical properties similar to the cytoplasmic androgen receptors in the epididymis and ventral prostate but different from the testicular androgen-binding protein (ABP). Like the androgen receptors in the prostate and epididymis, it has a sedimentation coefficient of about 7 S at low ionic strength, is eluted in or close to the void volume on Sephadex G-200 gel filtration (Stokes radius > 80 Å), has an isoelectric point of about 5.6-6.0 (mean) 5.8 and a relative mobility (Rf) of 0.4 in 3.25% acrylamide gels. Following the injection of 3H-labeled testosterone, T and DHT are bound selectively by the receptor. Relatively more [3H]T than [3H]DHT is present in bound and free fractions as well as in total testicular 105,000 g supernatant. Similar results are obtained from testicular incubations with equimolar amounts of [3H] T and [3H] DHT at 0°C in vitro. Saturation of receptor sites is achieved by incubation of testis supernatants with increasing amounts of [3H]T at 0°C. The number of available binding sites following post-hypophysectomy regression is estimated to be about 9 fmoles/mg protein, and the apparent equilibrium constant of dissociation is 7 × 10−10 M. The temperature stability and sulfhydryl dependence of the testicular androgen receptor are similar to androgen receptors in other organs. Binding is destroyed by heating the supernatants at 50°C for 30 min and by exposure to p-chloromercuriphenylsulfonate (1 mM) at 0°C for 60 min. Furthermore, like other androgen receptors, the half-time of dissociation of testicular androgen-receptor complexes at 0°C is extremely slow (t12 > 35 h). Separation of seminiferous tubules from interstitial tissue showed that a major portion of these receptors were localized within the seminiferous tubules.
摘要译文
未成熟大鼠睾丸含有睾酮（T）和5α-二睾酮（DHT）的特异性结合蛋白，其物理化学性质与附睾和腹侧前列腺中的细胞质雄激素受体相似，但不同于睾丸雄激素结合蛋白（ABP）。与前列腺和附睾中的雄激素受体一样，它在低离子强度下具有约7 S的沉降系数，在Sephadex G-200凝胶过滤（斯托克斯半径>80Å）时在空隙体积中或接近空隙体积洗脱，具有在3.25％丙烯酰胺凝胶中，等电点约为5.6-6.0（平均值）5.8，相对迁移率（R f）为0.4。注射 3 H-标记的睾酮后，T和DHT被受体选择性结合。相对更多[ 3 H] T比[ 3 H] DHT存在于结合和游离部分以及总睾丸105,000g上清液中。在0℃体外，用等摩尔量的[ 3 H] T和[ 3 H] DHT进行睾丸孵育，获得了类似的结果。通过在0℃下将睾丸上清液与递增量的[3] H 2 T温育来实现受体位点的饱和。在垂体切除后回归后可用结合位点的数量估计为约9fmoles / mg蛋白质，并且解离的表观平衡常数为7×10 -10 M.温度稳定性和巯基依赖性睾丸雄激素受体与其他器官中的雄激素受体相似。通过在50℃加热上清液30分钟并通过在0℃下暴露于对氯甲基苯基磺酸盐（1mM）60分钟来破坏结合。此外，与其他雄激素受体一样，睾丸雄激素 - 受体复合物在0℃解离的半衰期非常缓慢（t12> 35小时）。从间质组织分离曲细精管显示这些受体的主要部分位于曲细精管内。
William S.McLean[a];Albert A.Smith[a];VidarHansson[∗];OddvarNaess[∗];Shihadeh N.Nayfeh[a];Frank S.French[a];. Further characterization of the androgen receptor in rat testis[J]. Molecular and Cellular Endocrinology, 1976,4(4): 239-255