Cuthill S, Wilhelmsson A, Mason G G, Gillner M, Poellinger L, Gustafsson J A
Department of Medical Nutrition, Karolinska Institute, Huddinge University Hospital, Sweden.
J Steroid Biochem. 1988;30(1-6):277-80. doi: 10.1016/0022-4731(88)90106-9.
The physico-chemical properties of the dioxin and glucocorticoid receptors from rat liver and wild-type and mutant cell lines were investigated and compared. In rat liver, the receptors are virtually indistinguishable. Both are highly asymmetrical proteins with axial ratios of 12-15, have Stokes radii of 6 nm and sedimentation coefficients of approximately 4 S. This results in a calculated apparent mol. wt of approximately 100,000. The dioxin receptor from the mouse hepatoma cell line Hepa 1c1c7 represents an atypical form of the dioxin receptor with a pronounced tendency to aggregate to form Mr approximately equal to 300,000 complexes in high ionic strength and in the absence of sodium molybdate. In the presence of sulphydryl reducing agents, however, the Hepa 1c1c7 dioxin receptor dissociates to an Mr approximately 100,000 species. In analogy to the nt- mutant glucocorticoid receptor in mouse lymphoma cells, there is no gross change in the structure of the nt- dioxin mutant in mouse hepatoma cells compared with the wild-type receptor. The nt- dioxin receptor does, however, have a reduced affinity for DNA.
对来自大鼠肝脏以及野生型和突变细胞系的二噁英受体和糖皮质激素受体的物理化学性质进行了研究和比较。在大鼠肝脏中，这些受体几乎无法区分。两者都是高度不对称的蛋白质，轴比为12 - 15，斯托克斯半径为6纳米，沉降系数约为4 S。这导致计算出的表观分子量约为100,000。来自小鼠肝癌细胞系Hepa 1c1c7的二噁英受体代表了二噁英受体的一种非典型形式，在高离子强度且不存在钼酸钠的情况下，具有明显的聚集倾向，形成分子量约为300,000的复合物。然而，在存在巯基还原剂的情况下，Hepa 1c1c7二噁英受体解离为分子量约为100,000的物种。与小鼠淋巴瘤细胞中的nt - 突变糖皮质激素受体类似，与野生型受体相比，小鼠肝癌细胞中的nt - 二噁英突变体的结构没有明显变化。然而，nt - 二噁英受体对DNA的亲和力降低。
