THYROID HORMONE INTERACTIONS WITH CELLS AND PROTEINS

甲状腺激素结合球蛋白(TBG)和皮质醇结合球蛋白(CBG)是 丝氨酸蛋白酶家族的成员(蛇)，包括急性 相蛋白，α1-抗胰蛋白酶和抗1-抗胰凝乳素。 肝细胞中后两种蛋白质的合成被促进 细胞因子IL-6，但TBG和CBG合成减少。这个 IL-6降低了TbG基因的转录速率，而TbG基因的转录速率 CBG基因没有改变。急性期CBG合成减少 导致局部游离皮质醇水平升高的反应可能起作用 在抗击炎症方面的作用。 继续研究甲状腺激素与高密度脂蛋白载脂蛋白的结合 光亲和标记现在已经证明不仅与apoA-I结合，而且 也包括次要载脂蛋白，包括载脂蛋白A-II、载脂蛋白A-IV、载脂蛋白C-I、载脂蛋白II 和III，以及apoE。因此，T4结合可以是 载脂蛋白，并可能在细胞内靶向 甲状腺激素。 亲和标记试剂N-溴乙酰甲状腺素和N-溴乙酰基 三碘甲腺原氨酸的合成和提纯采用了新的方法，这些方法 导致制备更纯净和更好表征的产品 比以前可用的更多。这些试剂被广泛用于 甲状腺激素结合蛋白的亲和标记。

Thyroxine-binding globulin (TBG) and cortisol binding globulin (CBG) are members of the serine protease family (serpins) which include the acute phase proteins, alpha 1-antitrypsin and anti 1-antichymotrypsin. Synthesis of the latter two proteins in hepatocytes is increased by the cytokine IL-6, but synthesis of TBG and CBG are decreased. The transcription rate of the TBG gene is decreased by IL-6, while that of the CBG gene is unaltered. The decrease in CBG synthesis in the acute phase reaction, resulting in a local increase in free cortisol levels, may play a role in combating inflammation. Continuation of work on thyroxine binding to apolipoproteins of HDL by photoaffinity labeling has now demonstrated binding not only to apoA-I but also to the minor apolipoproteins, including apoA-II, apoA-IV, apoC-I, II and III, and apoE. Thus, T4 binding may be a general property of apolipoproteins and may have a role in the intracellular targeting of thyroid hormone. The affinity labeling reagents, N-bromoacetyl thyroxine and N-bromoacetyl triiodothyronine have been synthesized and purified by new methods which lead to the preparation of more pure and better characterized products than were previously available. These reagents are widely used for affinity labeling of thyroid hormone binding proteins.