Ogle T F, Beyer B K
J Steroid Biochem. 1982 Feb;16(2):147-50. doi: 10.1016/0022-4731(82)90160-1.
We have attempted to delineate some salient features of the progesterone binding site of the cytosol progesterone receptor (Rp) in rat placenta by studying the binding profile of various chemical modifications of the progesterone molecule (P). The relative competition ratio (RCR) was used to calculate the relative affinity of P and the modified ligand for receptor (Kaprog/Kainh). Cortisol exhibited no appreciable binding. Other corticoids (corticosterone, deoxycorticosterone, 11 beta-hydroxyprogesterone) had relative affinities 10-30-fold lower than P. Alterations in the structure of P which caused extensive declines in relative binding affinity (i.e. greater than or equal to 100-fold) include: reduction of A-ring to the 5 alpha-stereoisomere (A/B trans), introduction of a 17 alpha-hydroxyl group greater than removal of C17 side chain greater than reduction of C20 carbonyl. The binding profile of the rat placental Rp was similar to that described for uterine Rp from other species indicating a high degree of conservation of molecular structure for the progesterone receptor binding site from species to species.
我们试图通过研究孕酮分子（P）各种化学修饰的结合情况，来描绘大鼠胎盘胞质孕酮受体（Rp）孕酮结合位点的一些显著特征。相对竞争率（RCR）用于计算P和修饰配体对受体的相对亲和力（Kaprog/Kainh）。皮质醇没有明显的结合。其他皮质激素（皮质酮、脱氧皮质酮、11β-羟基孕酮）的相对亲和力比P低10 - 30倍。导致相对结合亲和力大幅下降（即大于或等于100倍）的P结构改变包括：A环还原为5α-立体异构体（A/B反式）、引入17α-羟基大于去除C17侧链大于C20羰基还原。大鼠胎盘Rp的结合情况与其他物种子宫Rp的描述相似，表明不同物种间孕酮受体结合位点的分子结构具有高度保守性。
