High molecular weight forms of adrenocorticotropic hormone are glycoproteins.
High molecular weight forms of adrenocorticotropic hormone are glycoproteins.
复制标题
高分子量形式的促肾上腺皮质激素是糖蛋白。
DOI：
10.1016/s0021-9258(17)33364-1
复制
发表时间：
1976
期刊：
影响因子：
--
通讯作者：
D. Guenzi
中科院分区：
文献类型：
--
作者：
B. Eipper;R. Mains;D. Guenzi
小鼠垂体瘤细胞(At-20/D-16v)在含有[~3H]氨基葡萄糖或[~3H]甘露糖的培养液中孵育。对细胞提取液和培养液免疫沉淀物的分析表明，三种高分子量ACTH均掺入了[~3H]氨基葡萄糖和[~H]甘露糖，而在MR=4,500 ACTH中没有掺入LABEL(与ACTHα(1-39)的39个氨基酸多肽形式相似)。根据十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法，这些糖蛋白形式的ACTH的表观分子量分别为31,000，23,000和13,000。在6M盐酸胍中的凝胶过滤表明，这些形式的ACTH的分子量大大降低；十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法经常被发现高估了糖蛋白的分子量。肿瘤细胞提取物中很大一部分高分子量ACTH与刀豆蛋白A-琼脂糖柱结合，并可用0.2Mα-甲基-D-甘露糖苷洗脱；猪α(1-39)不与刀豆蛋白A-琼脂糖结合。用刀豆蛋白A亲和层析法可在小鼠和牛脑垂体提取液中检测到大分子糖蛋白ACTH。
Mouse pituitary tumor cells (AtT-20/D-16v) were incubated in medium containing [3H] glucosamine or [3H] mannose. By analyzing immunoprecipitates of cell extracts and culture medium it was shown that [3H] glucosamine and [3H] mannose were incorporated into all three high molecular weight forms of ACTH; label was not incorporated into Mr=4,500 ACTH (which is thought to be similar to the 39 amino acid polypeptide form of ACTH, alpha(1-39)). Based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis the apparent molecular weights of these glycoprotein forms of ACTH were 31,000, 23,000, and 13,000. Gel filtration in 6 M guanidine HCl indicated that the molecular weights of these forms of ACTH were substantially lower; sodium dodecyl sulfate-polyacrylamide gel electrophoresis has often been found to overestimate the molecular weight of glycoproteins. A significant fraction of the high molecular weight ACTH in tumor cell extracts binds to columns of concanavalin A-agarose and can be eluted with 0.2 M alpha-methyl-D-mannopyranoside; porcine alpha(1-39) does not bind to concanavalin A-agarose. High molecular weight glycoprotein ACTH can be detected in extracts of mouse and bovine pituitary by using concavalin A affinity chromatography.