Azimova Sh S, Normatov K, Umarova G D, Kalontarov A I, Makhmudova A A
Biokhimiia. 1985 Nov;50(11):1926-32.
The effect of tyroxin-binding prealbumin (TBPA) of blood serum on the template activity of chromatin was studied. It was found that the values of binding constants of TBPA for T3 and T4 are 2 X 10(-11) M and 5 X 10(-10) M, respectively. The receptors isolated from 0.4 M KCl extract of chromatin and mitochondria as well as hormone-bound TBPA cause similar effects on the template activity of chromatin. Based on experimental results and the previously published comparative data on the structure of TBPA, nuclear, cytoplasmic and mitochondrial receptors of thyroid hormones as well as on translocation across the plasma membrane and intracellular transport of TBPA, a conclusion was drawn, which suggested that TBPA is the "core" of the true thyroid hormone receptor. It was shown that T3-bound TBPA caused histone H1-dependent conformational changes in chromatin. Based on the studies with the interaction of the TBPA-T3 complex with spin-labeled chromatin, a scheme of functioning of the thyroid hormone nuclear receptor was proposed.
研究了血清甲状腺素结合前白蛋白（TBPA）对染色质模板活性的影响。发现TBPA与T3和T4的结合常数分别为2×10⁻¹¹M和5×10⁻¹⁰M。从染色质和线粒体的0.4M KCl提取物中分离出的受体以及激素结合的TBPA对染色质的模板活性产生类似影响。基于实验结果以及先前发表的关于TBPA结构、甲状腺激素的核、细胞质和线粒体受体以及TBPA跨质膜转运和细胞内运输的比较数据，得出结论，表明TBPA是真正甲状腺激素受体的“核心”。结果表明，结合T3的TBPA会导致染色质中依赖组蛋白H1的构象变化。基于对TBPA-T3复合物与自旋标记染色质相互作用的研究，提出了甲状腺激素核受体的作用机制。
