Myatt L, Wittliff J L
J Steroid Biochem. 1986 May;24(5):1041-8. doi: 10.1016/0022-4731(86)90357-2.
The ionic species of cytosol estrogen receptors from mature rat uteri have been compared by HPIEC on a SynChrom AX-1000 column when complexed with either [125I]iodoestradiol, [3H]estradiol or [3H]4-hydroxy tamoxifen. Three species of receptors (isoforms) each suppressible by excess competitor were fractionated at identical salt concentrations regardless of ligand employed. One species eluted in the column void volume (10 mM) and the others at congruent to 90 mM and congruent to 155 mM phosphate. Activation of receptor complexes by increasing time of incubation with ligand from 1 to 24 h at 4 degrees C or addition of 10 mM GTP increased the proportion of the congruent to 90 mM species for all 3 ligands. The addition of 10 mM molybdate to homogenization and HPIEC buffers resulted in only two species being resolved at 10 and 110 mM phosphate. These species were again identical regardless of ligand employed. Increasing concentrations of estradiol (1-40 nM) tamoxifen (20 nM-4 microM) and 4-hydroxy tamoxifen (2-400 nM) were able to compete for binding of [125I]iodoestradiol to each of the three ionic species. Binding to each species was inhibited equally by each concentration of competitor. There was no preferential or unique association of estrogen or antiestrogen with any of the ionic species and all ligands gave identical ionic species of non-activated and activated receptor complexes.
当与[125I]碘雌二醇、[3H]雌二醇或[3H]4-羟基他莫昔芬复合时，已通过在SynChrom AX - 1000柱上的高效离子交换色谱法（HPIEC）比较了成熟大鼠子宫胞质溶胶雌激素受体的离子种类。三种受体（亚型）每种都可被过量的竞争者抑制，无论使用何种配体，均在相同盐浓度下进行分离。一种亚型在柱空体积（10 mM）处洗脱，其他亚型在约90 mM和约155 mM磷酸盐处洗脱。通过在4℃下将与配体孵育的时间从1小时增加到24小时或添加10 mM GTP来激活受体复合物，可增加所有3种配体中约90 mM亚型的比例。在匀浆缓冲液和HPIEC缓冲液中添加10 mM钼酸盐后，在10 mM和110 mM磷酸盐处仅分离出两种亚型。无论使用何种配体，这些亚型再次相同。雌二醇（1 - 40 nM）、他莫昔芬（20 nM - 4 μM）和4-羟基他莫昔芬（2 - 400 nM）浓度的增加能够竞争[125I]碘雌二醇与三种离子种类中每一种的结合。每种浓度的竞争者对与每种亚型的结合抑制程度相同。雌激素或抗雌激素与任何离子种类之间均无优先或独特的关联，并且所有配体产生的未激活和激活受体复合物的离子种类相同。
