Licht P, Papkoff H, Bona-Gallo A, Aggarwal B B
Gen Comp Endocrinol. 1983 Sep;51(3):414-22. doi: 10.1016/0016-6480(83)90058-8.
Follicle-stimulating hormone (FSH) from the ostrich, Struthio camelus, was dissociated by methods previously used to prepare subunits from mammalian gonadotropins. Two chemically dissimilar subunits were obtained from the ostrich FSH and these resembled the alpha- and beta-subunits of mammalian FSH in amino acid composition. The subunits were relatively inactive in radioimmunoassay, radioreceptorassay, and bioassay when tested alone, but significant activity was regenerated upon their recombination. Incubations of mixtures of one of the ostrich subunits with the opposing subunit of ovine FSH also resulted in a significant regeneration of binding and biological activity in FSH assays. These hybrid recombinants demonstrated that the species specificity of the FSH molecule is conferred entirely by the source of the beta-subunit; in fact, hybrids formed between ovine LH-alpha and either ovine or ostrich FSH-beta were more potent in FSH assays than were those containing even two homologous FSH subunits. In contrast, there was little regeneration of LH bioactivity when FSH subunits (from ostrich or sheep) were combined with the subunits of ovine LH, although some LH binding activity was obtained when the mixture contained either one of the LH subunits; i.e., even LH-alpha + FSH-beta showed significant enhancement of binding activity for LH receptors. Thus, the subunits of avian FSH show biochemical and functional homologies to those of mammalian FSH, but there is only limited interchangeability with ovine LH subunits.
来自鸵鸟（鸵鸟属骆驼鸵鸟）的促卵泡激素（FSH）通过先前用于从哺乳动物促性腺激素制备亚基的方法进行解离。从鸵鸟FSH中获得了两种化学性质不同的亚基，它们在氨基酸组成上类似于哺乳动物FSH的α和β亚基。单独测试时，这些亚基在放射免疫测定、放射受体测定和生物测定中相对无活性，但重组后可显著恢复活性。将一种鸵鸟亚基与绵羊FSH的相对亚基的混合物进行孵育，也会在FSH测定中显著恢复结合和生物活性。这些杂交重组体表明，FSH分子的物种特异性完全由β亚基的来源决定；事实上，绵羊LH-α与绵羊或鸵鸟FSH-β形成的杂交体在FSH测定中比那些甚至含有两个同源FSH亚基的杂交体更有效。相比之下，当FSH亚基（来自鸵鸟或绵羊）与绵羊LH的亚基结合时，LH生物活性几乎没有恢复，尽管当混合物中含有任何一个LH亚基时可获得一些LH结合活性；即，即使是LH-α + FSH-β对LH受体的结合活性也有显著增强。因此，鸟类FSH的亚基与哺乳动物FSH的亚基在生化和功能上具有同源性，但与绵羊LH亚基的互换性有限。
