Smith B R, Buckland P R
Ciba Found Symp. 1982(90):114-52. doi: 10.1002/9780470720721.ch8.
The thyrotropin (thyroid-stimulating hormone or TSH) receptor is an amphiphilic membrane component with a relative molecular mass of about 200,000 as judged by gel filtration and an isoelectric point close to pH 5. Analyses with chemical, enzymic and affinity probes indicate that the receptor is a glycoprotein containing a disulphide bridge and that the integrity of the disulphide bond is essential for maintaining the structure of the TSH-binding site. Serum from patients with Graves' disease contains antibodies which inhibit the binding of TSH to its receptor and there is considerable evidence that this effect is due to a direct interaction between the antibodies and the receptor. The antibody-receptor interaction is probably responsible for the TSH agonist properties of Graves' serum and, similarly, the TSH antagonist properties of the sera from a small number of patients can be explained on the basis of antibody-receptor binding. Although TSH and IgG from Graves' disease patients appear to bind to the same receptor, the relationship between the sites for the two substances is not clearly understood. However, Fab fragments of Graves' IgG are as effective as intact IgG in competing with TSH for the receptor and gel filtration and immunoprecipitation studies indicate that the binding of hormone and antibody to the receptor is mutually exclusive. Current evidence suggests therefore that the binding sites for TSH and TSH receptor antibodies are very closely related and may well be identical.
促甲状腺激素（甲状腺刺激激素或TSH）受体是一种两亲性膜成分，通过凝胶过滤判断其相对分子质量约为200,000，等电点接近pH 5。用化学、酶和亲和探针分析表明，该受体是一种含有二硫键的糖蛋白，二硫键的完整性对于维持TSH结合位点的结构至关重要。格雷夫斯病患者的血清中含有抑制TSH与其受体结合的抗体，并且有大量证据表明这种作用是由于抗体与受体之间的直接相互作用。抗体-受体相互作用可能是格雷夫斯病血清TSH激动剂特性的原因，同样，少数患者血清的TSH拮抗剂特性也可以基于抗体-受体结合来解释。虽然格雷夫斯病患者的TSH和IgG似乎与同一受体结合，但两种物质结合位点之间的关系尚不清楚。然而，格雷夫斯病IgG的Fab片段在与TSH竞争受体方面与完整IgG一样有效，凝胶过滤和免疫沉淀研究表明激素和抗体与受体的结合是相互排斥的。因此，目前的证据表明TSH和TSH受体抗体的结合位点密切相关，很可能是相同的。
