Radioligand-dependent differences in the molecular properties of the mouse and rat hepatic aryl hydrocarbon receptor complexes.
Radioligand-dependent differences in the molecular properties of the mouse and rat hepatic aryl hydrocarbon receptor complexes.
复制标题
小鼠和大鼠肝芳烃受体复合物分子特性的放射性配体依赖性差异。
DOI：
10.1016/0003-9861(88)90043-4
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发表时间：
1988
影响因子：
3.9
通讯作者：
Safe,S
中科院分区：
文献类型：
--
作者：
Piskorska-Pliszczynska,J;Safe,S
以2，3，7，8-[3H]四氯二苯并对二恶英(TCDD)和2，3，7，8-[3H]四氯二苯并呋喃(TCDF)为放射性配基，比较了雄性Long-Evans大鼠和雄性C57BL/6小鼠肝细胞胞浆芳香烃(AhR)受体复合体的分子性质。在低盐缓冲溶液中，大鼠受体络合物的沉降系数、斯托克斯半径、相对分子质量、摩阻比、轴向比和凝胶渗透层析性质与配体无关。2，3，7，8-[3 H]TCDF受体复合体在蔗糖密度梯度分析中出现了9.5 S特异性结合峰和2.6 S非特异性结合峰，而相应的2，3，7，8-[3 H]TCDD受体复合体仅有9.6 S特异性结合峰；从Sephacryl S-300柱层析分离的2，3，7，8-[~3H]TCDF受体复合体洗脱的两个主峰的蔗糖密度梯度分析显示，在9.2和5.1S处有两个特异结合的峰。在高盐(0.4mKCl)缓冲液中孵育的大鼠肝细胞质受体复合体的分子性质是不依赖配体的，但有一个例外，即特异结合的分解的2，3，7，8-[~3H]TCDF受体复合体的沉降系数(6.8S)与相应的2，3，7，8-[3H]TCDF受体复合体(5.0 S)的沉降系数有显著差异。在高盐(0.4mKCl)中孵育的小鼠受体复合体的主要差异与直接孵育和凝胶渗透层析后得到的复合体的沉降系数有关。例如，两种配体经Sephacryl S-300柱层析后都得到两个特异结合的络合物，离心后得到~9和~5个S峰，这表明聚集和解离的受体络合物之间存在一定的平衡。2，3，7，8-[~3H]TCDF小鼠受体复合体在低盐和高盐缓冲液中孵育后的行为相似，只是凝胶渗透层析部分的蔗糖密度梯度分析显示出一个额外的特异结合峰，该峰在7.2S处沉淀。这些研究表明，AH受体的分子性质取决于细胞质受体制剂的来源、孵育介质的离子强度和放射性配基的结构。
A comparison of the molecular properties of the male Long-Evans rat and male C57BL/ 6 mouse hepatic cytosolic aryl hydrocarbon (Ah) receptor complex was determined using 2,3,7,8-[3H]tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,7,8-[3H]tetrachlorodibenzofuran (TCDF) as radioligands. In low salt buffer, the sedimentation coefficients, Stokes radii, relative molecular masses, frictional ratios, axial ratios and gel permeation chromatographic properties of the rat receptor complexes were ligand independent. In contrast, there were several ligand-dependent differences in the mouse Ah receptor complexes formed after incubation in low salt buffer and these include: sucrose density gradient analysis of the 2,3,7,8-[3H]TCDF receptor complex gave a 9.5 S specifically bound peak and a 2.6 S nonspecifically bound peak whereas the corresponding 2,3,7,8-[3H]TCDD receptor complex gave a single 9.6 S specifically bound peak; sucrose density gradient analysis of the two major peaks eluted from a Sephacryl S-300 column chromatographie separation of the 2,3,7,8-[3H]TCDF receptor complex gave two specifically bound peaks at 9.2 and 5.1 S. The molecular properties of the rat hepatic cytosolic receptor complexes incubated in high salt (0.4mKCl) buffer were ligand independent with one exception, namely the significant difference in the sedimentation coefficient of the specifically bound disaggregated 2,3,7,8-[3H]TCDD receptor complex (6.8 S) and the corresponding 2,3,7,8-[3H]TCDF receptor complex (5.0 S). The major ligand-dependent differences in the mouse receptor complexes incubated in high salt (0.4mKCl) were associated with the sedimentation coefficients of the complexes derived after direct incubation and after gel permeation chromatography. For example, both ligands gave two specifically bound complexes after chromatography on Sephacryl S-300 column and centrifugation of these fractions gave both the ~9 and ~5 S peaks; this suggested that there was some equilibration between the aggregated and disaggregated receptor complexes. The behavior of the 2,3,7,8-[3H]TCDF mouse receptor complex was similar after incubation in low or high salt buffer except that sucrose density gradient analysis of the gel permeation Chromatographic fractions gave an additional specifically bound peak which sedimented at 7.2 S. These studies demonstrate that the molecular properties of the Ah receptor were dependent on the source of the cytosolic receptor preparation, the ionic strength of the incubation media, and the structure of the radioligand.