Manjunath P, Sairam M R
J Biol Chem. 1982 Jun 25;257(12):7109-15.
A chemical method of deglycosylation of human choriogonadotropin (hCG) was used to assess the role of carbohydrate moiety in the maintenance of quaternary structure and functional parameters such as receptor binding, immunological activity, and in vitro biological response. Treatment of purified hCG with anhydrous HF at 0 degrees C for 60 min was effective in removing more than 75% of the carbohydrate moiety. This extent of deglycosylation altered its chromatographic characteristics as revealed by retarded behavior on Sephadex G-100 and failure to be retained on concanavalin A-Sepharose. The electrophoretic heterogeneity present in native hCG was markedly reduced by deglycosylation. The deglycosylated hCG was stable in the lyophilized form and retained its quaternary structure as revealed by the fluorescence probe 8-anilino 1-naphthalene sulfonic acid, receptor binding, and immunological activities. Unlike receptor binding and immunological activities, which were fully retained, the ability of the hormone to stimulate cyclic AMP accumulation in vitro in rat interstitial cells was completely abolished.
采用一种对人绒毛膜促性腺激素（hCG）进行去糖基化的化学方法，来评估碳水化合物部分在维持四级结构以及受体结合、免疫活性和体外生物学反应等功能参数方面的作用。在0℃用无水HF处理纯化的hCG 60分钟，可有效去除超过75%的碳水化合物部分。这种去糖基化程度改变了其色谱特征，如在Sephadex G - 100上的滞留行为延迟以及不能保留在伴刀豆球蛋白A - 琼脂糖上所显示的那样。去糖基化显著降低了天然hCG中存在的电泳异质性。去糖基化的hCG以冻干形式稳定，并通过荧光探针8 - 苯胺基 - 1 - 萘磺酸、受体结合和免疫活性显示保留了其四级结构。与完全保留的受体结合和免疫活性不同，该激素刺激大鼠间质细胞体外积累环磷酸腺苷的能力被完全消除。
