期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：9
页码：5211-5215
DOI：10.1073/pnas.77.9.5211
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The biosynthesis of human corticotropin (ACTH) was studied in organ culture of pituitary adenomas and by translating mRNA from an ectopic ACTH-producing tumor in a cell-free system. Peptides similar to human ACTH, beta-lipotropin, and the amino-terminal glycopeptide are cleaved from a common precursor with an apparent molecular weight of 35,000 on sodium dodecyl sulfate/polyacrylamide gels. The precursors synthesized in pituitary and ectopic ACTH-producing tissues are indistinguishable. The cleavage sites of the peptide chain appear to be similar to those previously deduced for murine and bovine ACTH. Immunoprecipitation studies suggest that the primary structure of the precursor peptide is similar in all three species. However, glycosylation is different in the human and murine precursors: the precursor to human ACTH appears to be glycosylated only in the amino-terminal fragment, not in the ACTH or beta-lipotropin sequences. Studies with an autopsied normal human pituitary suggest that neither normal nor adenomatous pituitary tissue glycosylates the ACTH sequence.
