Schrader W T
Metabolism. 1982 Jul;31(7):654-7. doi: 10.1016/0026-0495(82)90194-9.
Chicken oviduct progesterone receptor has been purified to homogeneity. The protein consists of two dissimilar hormone-binding subunits, A and B, present in equal amounts in the complex. They have molecular weights of 79,000 and 108,000, respectively, as shown by both SDS-gel electrophoresis of the purified proteins and photoaffinity labeling of both with a labeled synthetic progestin. The two subunits show considerable homology (or identity) of structure at the hormone-binding domain, located at the N-terminus of the proteins. Considerable divergence of sequence must exist elsewhere in A and B, as shown by tryptic peptide mapping and by the fact that subunit A has a strong DNA-binding site lacking in B. Both are phosphorylated in vitro by cAMP-dependent protein kinase; this phosphorylation appears to be responsible for creation of a second, weaker progesterone-binding site on each subunit.
鸡输卵管孕酮受体已被纯化至同质。该蛋白质由两个不同的激素结合亚基A和B组成，在复合物中含量相等。通过纯化蛋白质的SDS-凝胶电泳以及用标记的合成孕激素对两者进行光亲和标记显示，它们的分子量分别为79,000和108,000。这两个亚基在位于蛋白质N端的激素结合结构域处显示出相当程度的结构同源性（或同一性）。如胰蛋白酶肽图谱所示，以及亚基A具有B所缺乏的强DNA结合位点这一事实表明，A和B在其他地方必定存在相当大的序列差异。两者在体外均被cAMP依赖性蛋白激酶磷酸化；这种磷酸化似乎负责在每个亚基上产生第二个较弱的孕酮结合位点。
