Research for structure-function relationship in human gonadotropins

为了分析二硫键在人促性腺激素细胞内的作用，通过位点定向诱变将每个β亚基的半胱氨酸残基转化为其他氨基酸序列。使用突变体β亚单位获得以下结果：与α亚基的组装被hCG β亚基中任何二硫键的消除所阻断，然而，每个二硫对之间的结合率存在差异2。2 .半胱氨酸26/110处的二硫键对hCG和LH β亚基的分泌有调节作用，而对FSH β亚基无调节作用。消除hCGbeta中23/72位二硫键后，观察到不同的免疫反应。受体结合和生物活性不受二硫键断裂的影响。测定了hcgβ中二硫键的形成过程。这些方法可用于分析其他多肽的结构与功能关系。

To analyze the intracellular roles of disulfide bonds in human gonadotropins, the cystein residues in each beta subunit were converted to other amino acid sequences by site-directed mutagenesis. The following results were obtained using the mutant beta subunits.1. Assembly with alpha subunit was blocked by the elimination of any disulfide bonds in hCG beta subunit, however, there were differences in the binding rate among each disulfide pair.2. The disulfide bond at cysteins 26/110 had regulating role in secretions of beta subunits of hCG and LH,but not in FSH beta subunit.3. Various immunological reactivities were observed when the disulfide bond at 23/72 in hCGbeta were eliminated.4. Receptor bindings and biological activities were not affected by disulfide bond breakage in hCGbeta.5. The process of disulfide bond formation in hCGbeta were also determined. These methods presented here could be useful to analyze the relationship between structure and function even in other peptides.