Interaction of the radiolabelled high-affinity anti-oestrogen [3H]H1285 with the cytoplasmic oestrogen receptor.
Interaction of the radiolabelled high-affinity anti-oestrogen [3H]H1285 with the cytoplasmic oestrogen receptor.
复制标题
放射性标记的高亲和力抗雌激素 [3H]H1285 与细胞质雌激素受体的相互作用。
DOI：
10.1042/bj2170819
复制
发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Ruh,TS
中科院分区：
文献类型：
--
作者：
Keene,JL;Sweet,F;Ruh,MF;Ruh,TS
将高亲和力三芳基乙烯抗雌激素H1285 [4-（N，N-二乙基氨基乙氧基）-β-乙基-α-（对羟基苯基）-4′-甲氧基二苯乙烯]氚化至高比放射性（35 Ci/mmol）。[~ 3 H]H1285与H1285或雌二醇之间的竞争实验表明，这两种化合物都将与[~ 3 H]H1285竞争大鼠子宫胞液中雌激素特异性结合位点。在50%竞争水平下，[3 H]H1285对受体的亲和力至少是雌二醇的10倍。与[3 H]雌二醇相比，[3 H]H1285似乎对雌激素受体的结合率至少是其两倍。此外，[3 H]H1285与雌激素受体特异性结合的解离半衰期（t1/2）在0 ℃时约为220 h，而[3 H]雌二醇的值为60 h。由于[3 H]H1285与雌激素受体的解离极其缓慢，我们能够在5-20%蔗糖密度梯度上，在0.4 M-KCl存在下，比较[3 H]H1285-受体复合物与[3 H]雌二醇-受体复合物的沉降曲线。[3 H]雌二醇-受体复合物在4.4 S处有一个主峰，在5.6 S处有一个较小的峰，而[3 H]H1285-受体复合物的5.6 S峰总是高于4.4 S峰。在存在和不存在10 mM-β-雌二醇钠的情况下，[3 H]H1285-受体复合物和在25 ℃预活化30 min的[3 H]雌二醇-受体复合物在20 ℃下的解离行为之间存在显著差异。在20 ℃下，当热处理过程中存在β-雌二醇时，[3 H]雌二醇-受体复合物的解离t1/2从1.5 h降低至0.5 h，而[3 H]H1285-受体复合物的解离t1/2在两种条件下均为5 h。这些观察结果表明，在H1285和雌二醇与雌激素受体的初始相互作用中存在根本差异。
The high-affinity triarylethylene anti-oestrogen H1285 [4-(NN-diethylaminoethoxy)-beta-ethyl-alpha-(p-hydroxyphenyl) −4′-methoxystilbene] was tritiated to high specific radioactivity (35 Ci/mmol). Competition experiments between [3H]H1285 and H1285 or oestradiol demonstrated that both compounds would compete with [3H]H1285 for oestrogen-specific binding sites in rat uterine cytosol. [3H]H1285 had at least 10 times the affinity for the receptor compared with oestradiol at the 50% competition level. [3H]H1285 appeared to have at least twice the association rate for the oestrogen receptor compared with [3H]oestradiol. In addition, the dissociation half-life (t1/2) of specific binding of [3H]H1285 to oestrogen receptors at 0 degrees C was about 220 h compared with a value of 60 h for [3H]oestradiol. Because of the extremely slow dissociation of [3H]H1285 from the oestrogen receptor, we were able to compare the sedimentation profiles of [3H]H1285-receptor complexes with those of [3H]oestradiol-receptor complexes in the presence of 0.4 M-KCl on 5-20% sucrose density gradients. [3H]Oestradiol-receptor complexes had a major peak at 4.4 S with a smaller peak at 5.6 S, whereas with [3H]H1285-receptor complexes the 5.6 S peak was always higher than the 4.4 S peak. There was significant variation between the dissociation behaviour at 20 degrees C of [3H]H1285-receptor complexes and [3H]oestradiol-receptor complexes pre-activated at 25 degrees C for 30 min in the presence and in the absence of 10 mM-sodium molybdate. The dissociation t1/2 of [3H]oestradiol-receptor complexes at 20 degrees C decreased from 1.5 h to 0.5 h when molybdate was present during heat treatment whereas the dissociation t1/2 for [3H]H1285-receptor complexes was 5 h for both conditions. These observations indicate that there are fundamental differences in the initial interaction of H1285 and oestradiol with the oestrogen receptor.