A rapid, simple and nonhazardous assay method for endcrine disruptors was developed using an estrogen receptor (ER) and fluorescence polarization (FP). Among the fluorescent compounds, the 17α-fluorescein-labeled estradiol derivative was selected as the most suitable ligand for the ER binding assay, since it showed the highest affinity to ER. In the Scatchard plot analysis, its convex curve exhibited a positive cooperative binding, indicating the induction of a conformational change of the ER with the binding of the ligand to form a dimer and to increase the affinity for the additional ligand. On the basis of the Hill plot analysis, its dissociation constant and Hill coefficient were 10.4 nM and 1.63, respectively. A competitive binding assay with an unlabeled 17β-estradiol (E2) yielded an IC50 value of 2.82 nM and a Hill coefficient of 1.67, thus providing a Ki value of 0.65 nM. In the same manner, the Hill coefficients for estrone, estriol, diethylstilbestrol, and tamoxifen were determined to be 0.99, 1.17, 1.59, and 2.44, respectively.
开发了一种快速、简单且无害的内分泌干扰物检测方法,该方法使用
雌激素受体(ER)和荧光偏振(FP)。在荧光化合物中,选择17α
荧光素标记的
雌二醇衍
生物作为最适合的ER结合检测
配体,因为它对ER表现出最高的亲和力。在Scatchard图分析中,其凸曲线显示出正合作结合,表明
配体结合后诱导了ER构象的变化,从而形成二聚体并增加对额外
配体的亲和力。根据Hill图分析,其解离常数为10.4 nM,Hill系数为1.63。与未标记的17β-
雌二醇(E2)进行的竞争结合实验得到IC50值为2.82 nM,Hill系数为1.67,从而提供了Ki值为0.65 nM。同样,
雌酮、
雌三醇、二
乙基苯酮和
他莫昔芬的Hill系数分别确定为0.99、1.17、1.59和2.44。