Eisen L P, Reichman M E, Thompson E B, Gametchu B, Harrison R W, Eisen H J
J Biol Chem. 1985 Sep 25;260(21):11805-10.
The region of the glucocorticoid receptor that reacted with a monoclonal antibody (BUGR-1) was identified. In order to identify the immunoreactive region, the rat liver glucocorticoid receptor was subjected to limited proteolysis; immunoreactive fragments were identified by Western blotting. The monoclonal antibody reacted with both the undigested Mr approximately 97,000 receptor subunit and a Mr approximately 45,000 fragment containing the steroid-binding and DNA-binding domains. Digestion by trypsin also produced two steroid-binding fragments of Mr approximately 27,000 and 31,000 which did not react with the antibody and an immunoreactive Mr approximately 16,000 fragment. This Mr approximately 16,000 fragment was shown to bind to DNA-cellulose, indicating that it contained a DNA-binding domain of the receptor. The undigested receptor must have steroid associated with it to undergo activation to a DNA-binding form. However, the Mr approximately 16,000 immunoreactive fragment binds to DNA-cellulose even if it is obtained by digestion of the steroid-free holoreceptor which does not itself bind to DNA.
已鉴定出与单克隆抗体（BUGR-1）发生反应的糖皮质激素受体区域。为了鉴定免疫反应区域，对大鼠肝脏糖皮质激素受体进行了有限的蛋白酶解；通过蛋白质印迹法鉴定免疫反应片段。该单克隆抗体与未消化的分子量约为97,000的受体亚基以及一个包含类固醇结合域和DNA结合域的分子量约为45,000的片段均发生反应。胰蛋白酶消化还产生了两个分子量约为27,000和31,000且不与该抗体发生反应的类固醇结合片段以及一个免疫反应性的分子量约为16,000的片段。已证明这个分子量约为16,000的片段能与DNA纤维素结合，表明它包含受体的一个DNA结合域。未消化的受体必须与类固醇结合才能被激活为DNA结合形式。然而，即使分子量约为16,000的免疫反应片段是通过对本身不与DNA结合的无类固醇全受体进行消化而获得的，它仍能与DNA纤维素结合。
