Geel S E, Gonzales L, Timiras P S
Endocr Res Commun. 1981;8(1):1-18. doi: 10.1080/07435808109065979.
Some properties of brain cytosol components that specifically bind L-triiodothyronine (T3) were examined in order to resolve their relevance and relationship to nuclear receptors. A marked variation in T3 binding activity was apparent among different brain areas. Binding exhibited temperature dependence and was maximal at 0 degrees C. The binding component was shown to be a protein that migrated as a single included peak on Sephadex G-100 columns at a position corresponding to a Stokes radium of 30A degrees and a M.W. of 54,000. On a linear glycerol gradient the T3-macromolecular complex was estimated to have a sedimentation constant of .4.2S. By combining sedimentation and gel filtration data the calculated M.W. was 53,000. With DEAE-cellulose chromatography the T3 complex eluted as a single peak at 115mM KH2PO4. The results indicate that the properties of the cytosol thyronine-binding protein are similar in many respects to those reported for nuclear receptors. In addition, the regional and developmental binding parameters parallel those for nuclei. We conclude that cytosolic recognition sites may function in the modulation of nuclear receptors and in addition serve to distinguish target from non-target tissue.
为了阐明它们与核受体的相关性及关系，对脑胞质溶胶中特异性结合L-三碘甲状腺原氨酸（T3）的成分的某些特性进行了研究。不同脑区的T3结合活性存在显著差异。结合表现出温度依赖性，在0℃时最大。结合成分被证明是一种蛋白质，在Sephadex G-100柱上以单一包容峰形式迁移，其位置对应于斯托克斯半径30埃和分子量54,000。在线性甘油梯度上，T3-大分子复合物的沉降常数估计为4.2S。结合沉降和凝胶过滤数据计算出的分子量为53,000。用DEAE-纤维素色谱法，T3复合物在115mM KH2PO4处作为单一峰洗脱。结果表明，胞质溶胶甲状腺素结合蛋白的特性在许多方面与报道的核受体特性相似。此外，区域和发育结合参数与细胞核的参数平行。我们得出结论，胞质溶胶识别位点可能在核受体的调节中起作用，并且还用于区分靶组织和非靶组织。
