Keel B A, Harms R L, Amir S M
Department of Obstetrics and Gynecology, University of Kansas School of Medicine, Wichita.
Endocr Res. 1990;16(2):151-63. doi: 10.1080/07435809009032996.
Chromatofocusing was used to characterize the charge microheterogeneity of crude pituitary, highly purified native bovine (b) and deglycosylated (dg) thyrotropin (TSH) preparations. Greater than 90% of crude pituitary TSH and native bTSH-I-1 bound to concanavalin-A (conA) columns while dgbTSH was excluded from the column. Extracts of ovine (o) pituitaries contained at least nine species (isohormones) of immunoreactive TSH when chromatofocused on pH 7.5-4 gradients. Highly purified native bTSH-I-1 displayed a similar elution profile. In contrast, dgbTSH eluted as a single homogeneous species with an apparent pI greater than 7.5. When subjected to chromatofocusing on a pH 10.5-7 gradient, 68% of crude pituitary oTSH and 96% of native bTSH-I-1 was bound to the column but could be eluted with NaCl indicating acidic species, while at least three peaks of dgbTSH could be resolved having apparent pI's of 9.12, 9.03 and 8.98. These data suggest that although removal of the carbohydrate moieties markedly alters the isohormone pattern of TSH, chemical deglycosylation does not completely eliminate the charge microheterogeneity of bTSH.
用色谱聚焦法对粗制垂体、高度纯化的天然牛（b）促甲状腺激素（TSH）制剂以及去糖基化（dg）促甲状腺激素制剂的电荷微不均一性进行了表征。粗制垂体TSH和天然bTSH-I-1中超过90%与伴刀豆球蛋白A（conA）柱结合，而dgbTSH被排除在柱外。当在pH 7.5 - 4梯度上进行色谱聚焦时，绵羊（o）垂体提取物中含有至少九种免疫反应性TSH（同激素）。高度纯化的天然bTSH-I-1呈现出相似的洗脱图谱。相比之下，dgbTSH以单一均一形式洗脱，表观pI大于7.5。当在pH 10.5 - 7梯度上进行色谱聚焦时，68%的粗制垂体oTSH和96%的天然bTSH-I-1与柱结合，但可用NaCl洗脱，表明为酸性物质，而dgbTSH至少可分辨出三个峰，表观pI分别为9.12、9.03和8.98。这些数据表明，虽然去除碳水化合物部分显著改变了TSH的同激素模式，但化学去糖基化并未完全消除bTSH的电荷微不均一性。
