Nakamura H, Tagami T, Masuda K, Mitani T, Imura H
Department of Internal Medicine, Kyoto University School of Medicine, Japan.
Biochem Biophys Res Commun. 1989 Apr 14;160(1):148-53. doi: 10.1016/0006-291x(89)91633-1.
It has been reported that c-erb A encodes nuclear T3 receptors (NT3R). Based on the sequence of c-erb A cDNA, we synthesized a polypeptide consisting of 15 amino acids, the sequence of which has high homology between c-erb A alpha 1 and beta. The antibody against this c-erb A peptide not only immunoprecipitated rat liver and kidney NT3R but also inhibited T3 binding to NT3R. In a displacement study, the inhibition of [125I]T3-binding by the antibody was parallel to that by T3 in terms of the concentration of the competitor added in the incubation mixture. Scatchard analysis revealed that the antibody decreased the value for the association constant in a dose dependent manner. The antibody did not bind T3 itself. The results show that the antibody against c-erb A peptide recognizes rat liver and kidney NT3R and that the sequence encoding this peptide, the closest carboxyl-terminal of c-erb A may be critical or at least closely related to the hormone binding.
据报道，c-erb A编码核甲状腺素受体（NT3R）。基于c-erb A cDNA的序列，我们合成了一种由15个氨基酸组成的多肽，其序列在c-erb Aα1和β之间具有高度同源性。针对这种c-erb A肽的抗体不仅能免疫沉淀大鼠肝脏和肾脏的NT3R，还能抑制甲状腺素与NT3R的结合。在置换研究中，就孵育混合物中添加的竞争者浓度而言，抗体对[125I]甲状腺素结合的抑制作用与甲状腺素的抑制作用平行。Scatchard分析表明，该抗体以剂量依赖的方式降低了缔合常数的值。该抗体本身不结合甲状腺素。结果表明，针对c-erb A肽的抗体识别大鼠肝脏和肾脏的NT3R，并且编码该肽的序列，即c-erb A最接近羧基末端的序列，可能对激素结合至关重要或至少与之密切相关。
