Mains R E, Eipper B A
Proc Natl Acad Sci U S A. 1975 Sep;72(9):3565-9. doi: 10.1073/pnas.72.9.3565.
The molecular weight of the adrenocorticotropic hormone (ACTH) activity in extracts of the separated anterior and intermediate-posterior lobes of the mouse pituitary was determined by gel filtration in guanidine-HCl. Following dilution or removal of the guanidine-HCl, ACTH activity was quantitated by both radioimmunoassay and bioassay. Extracts of the intermediate-posterior lobe contain approximately a tenth as much ACTH activity as extracts of the anterior lobe. In extracts of both the anterior and the intermediate-posterior lobes, about half of the immunological ACTH activity is similar in size to porcine ACTH (molecular weight 4000--5500). Two higher molecular weight forms of ACTH account for the remainder of the ACTH activity. About 40% of the immunological ACTH activity in anterior lobe extracts has a molecular weight of 6500--9000. Extracts of both the anterior lobe and the intermediate-posterior lobe contain ACTH activity with a molecular weight of 20,000--30,000. While this 20,000--30,000 molecular weight ACTH accounts for only 5% of the immunological ACTH activity in the anterior lobe extracts, it accounts for half of the immunological ACTH activity in extracts of the intermediate-posterior lobe. Extracts of an ACTH-secreting mouse pituitary tumor cell line (AtT-20/D-16v) contain the same three molecular weight forms of ACTH. Each of the three molecular weight forms of ACTH has a characteristic ratio of biological ACTH activity to immunological ACTH activity, independent of the source of the material (anterior lobe, intermediate-posterior lobe, or mouse pituitary tumor cell line).
通过在盐酸胍中进行凝胶过滤，测定了小鼠垂体分离的前叶和中间 - 后叶提取物中促肾上腺皮质激素（ACTH）活性的分子量。在稀释或去除盐酸胍后，通过放射免疫测定法和生物测定法对ACTH活性进行定量。中间 - 后叶提取物中的ACTH活性约为前叶提取物的十分之一。在前叶和中间 - 后叶的提取物中，约一半的免疫活性ACTH在大小上与猪ACTH（分子量4000 - 5500）相似。ACTH的另外两种较高分子量形式占ACTH活性的其余部分。前叶提取物中约40%的免疫活性ACTH分子量为6500 - 9000。前叶和中间 - 后叶的提取物都含有分子量为20,000 - 30,000的ACTH活性。虽然这种分子量为20,000 - 30,000的ACTH仅占前叶提取物中免疫活性ACTH的5%，但它占中间 - 后叶提取物中免疫活性ACTH的一半。一种分泌ACTH的小鼠垂体肿瘤细胞系（AtT - 20/D - 16v）的提取物含有相同的三种分子量形式的ACTH。ACTH的三种分子量形式中的每一种都具有生物ACTH活性与免疫活性ACTH活性的特征比率，与材料来源（前叶、中间 - 后叶或小鼠垂体肿瘤细胞系）无关。
