Kohn L D, Valente W A, Laccetti P, Cohen J L, Aloj S M, Grollman E F
Life Sci. 1983;32(1-2):15-30. doi: 10.1016/0024-3205(83)90170-4.
The thyrotropin receptor is proposed to contain both a glycoprotein and a ganglioside component. Monoclonal antibodies have been developed against soluble thyroid TSH receptor preparations and using Graves' lymphocytes. These show that initial recognition of thyrotropin requires the glycoprotein component, but that monoclonal antibodies to this component block thyrotropin function (blocking antibodies) rather than mimic thyrotropin. Monoclonal antibodies which stimulate thyroid activity in cultured cell systems (cAMP increase) or mouse bioassays, all interact with gangliosides. Using monoclonal antibodies to the glycoprotein component of the thyrotropin receptor, we show that two protein bands, molecular weights 18,000-23,000 and 50,000-55,000, are precipitated from detergent-solubilized preparations. Using a crosslinking procedure with 125I-labeled thyrotropin, we show that thyrotropin binding is related to the disappearance of the 18,000-23,000 molecular weight band on sodium dodecylsulfate gels and the appearance of a 30,000-33,000 molecular weight thyrotropin-membrane component complex. Higher molecular weight thyrotropin-membrane complexes of 75,000-80,000 and 250,000 are visualized when binding studies are performed at pH 7.4 in physiologic medium; larger amounts of the 30,000-33,000 complex are evident at pH 6.0 in a low salt medium. It is thus proposed that the glycoprotein component of the thyrotropin receptor is composed of two subunits with apparent molecular weights of 18,000-23,000 and 50,000-55,000; that the 18,000-23,000 subunit interacts with thyrotropin; and that different receptor subunits can exist depending on in vitro binding conditions. Using monoclonal-stimulating antibodies or natural autoimmune IgG preparations from patients' sera, we show that stimulating antibodies exhibit species-specific binding to human thyroid ganglioside preparations. Individual components or determinants of the thyrotropin receptor structure with specific autoimmune immunoglobulins.
促甲状腺激素受体被认为同时含有糖蛋白和神经节苷脂成分。已经制备了针对可溶性甲状腺促甲状腺激素受体制剂以及利用格雷夫斯病患者淋巴细胞的单克隆抗体。这些结果表明，促甲状腺激素的初始识别需要糖蛋白成分，但针对该成分的单克隆抗体阻断促甲状腺激素的功能（阻断抗体），而非模拟促甲状腺激素。在培养细胞系统（cAMP增加）或小鼠生物测定中刺激甲状腺活性的单克隆抗体，均与神经节苷脂相互作用。利用针对促甲状腺激素受体糖蛋白成分的单克隆抗体，我们发现从去污剂溶解的制剂中沉淀出两条蛋白带，分子量分别为18,000 - 23,000和50,000 - 55,000。通过用¹²⁵I标记的促甲状腺激素进行交联实验，我们发现促甲状腺激素结合与十二烷基硫酸钠凝胶上18,000 - 23,000分子量条带的消失以及30,000 - 33,000分子量的促甲状腺激素 - 膜成分复合物的出现有关。当在生理介质中pH 7.4进行结合研究时，可观察到分子量为75,000 - 80,000和250,000的更高分子量的促甲状腺激素 - 膜复合物；在低盐介质中pH 6.0时，30,000 - 33,000复合物的量更明显。因此，有人提出促甲状腺激素受体的糖蛋白成分由两个亚基组成，表观分子量分别为18,000 - 23,000和50,000 - 55,000；18,000 - 23,000亚基与促甲状腺激素相互作用；并且根据体外结合条件可存在不同的受体亚基。利用单克隆刺激抗体或患者血清中的天然自身免疫性IgG制剂，我们发现刺激抗体与人甲状腺神经节苷脂制剂表现出种属特异性结合。促甲状腺激素受体结构的各个成分或决定簇与特定的自身免疫性免疫球蛋白有关。
