一种抗促甲状腺激素β亚基的生物有效单克隆抗体的特性分析

Characterization of a bioeffective monoclonal antibody against thyrotropin beta-subunit.

作者信息

Hill B L, Lustbader J W, Erlanger B F

出版信息

Endocrinology. 1987 Feb;120(2):574-81. doi: 10.1210/endo-120-2-574.

Abstract

To describe a region of the TSH molecule participating in binding to receptor, a monoclonal antibody specific for a TSH epitope shared by beta-subunits of bovine (b), ovine (o), and human (h) TSH was obtained by immunization with mixtures of purified bTSH and hTSH. RIAs showed that the antibody also bound the beta-subunits of bLH, oLH, hLH, and hCG, but not the beta-subunits of porcine LH and TSH. Preincubation of [125I]iodo-bTSH with the antibody completely inhibited binding of the hormone to the TSH receptor of bovine thyroid membrane preparations at pH 7.4 in 50 mM NaCl (ED50 = 10 nM). The antibody also inhibited TSH-induced mitogenesis of FRTL-5 cells (ED50 = 50 nM). We conclude that the antibody binds to a site on the bTSH molecule that participates in high affinity binding of hormone to physiological TSH receptor. The target epitope includes a conserved structural determinant in beta-subunits of the glycoprotein hormones as well as a feature that allows discrimination of porcine hormones from those of bovine, ovine, and human origin.

摘要

为描述促甲状腺激素（TSH）分子中参与与受体结合的区域，通过用纯化的牛（b）、羊（o）和人（h）TSH的β亚基混合物免疫，获得了一种对bTSH、oTSH和hTSH的β亚基共有的TSH表位具有特异性的单克隆抗体。放射免疫分析（RIA）表明，该抗体也能结合bLH、oLH、hLH和hCG的β亚基，但不结合猪LH和TSH的β亚基。在50 mM NaCl、pH 7.4条件下，[125I]碘代-bTSH与该抗体预温育可完全抑制激素与牛甲状腺膜制剂的TSH受体结合（半数有效剂量[ED50]=10 nM）。该抗体还能抑制TSH诱导的FRTL-5细胞有丝分裂（ED50=50 nM）。我们得出结论，该抗体与bTSH分子上一个参与激素与生理性TSH受体高亲和力结合的位点结合。靶表位包括糖蛋白激素β亚基中的一个保守结构决定簇以及一个能区分猪激素与牛、羊和人源激素的特征。