| Autor: |
J A O'Neil, M Muszynski, R S Birnbaum, David C. Aron, Bernard A. Roos |
| Rok vydání: |
1982 |
| Předmět: |
|
| Zdroj: |
Journal of Biological Chemistry. 257:241-244 |
| ISSN: |
0021-9258 |
| DOI: |
10.1016/s0021-9258(19)68351-1 |
| Popis: |
The terminal hexadecapeptide sequence of preprocalcitonin (termed carboxyl-adjacent peptide, CAP, for its position relative to calcitonin) has been synthesized to establish a radioimmunoassay for an investigation of cross-reacting peptides in extracts of normal and neoplastic calcitonin-producing tissues. Gel filtration chromatography of a rat thyroid extract revealed a major peak of immunoreactive peptide of approximately the same molecular weight as synthetic CAP. A minor peak of higher molecular weight immunoreactive material was also observed. The isoelectric point of both the thyroid peptide and synthetic material was about 5.2. Immunoreactive CAP and calcitonin were found in approximately equimolar amounts in normal thyroid and in anaplastic and well differentiated rat medullary thyroid carcinomas. Immunoreactive CAP was not detected in any tissue which did not contain calcitonin. Monolayer cultures of a rat medullary thyroid carcinoma contained and secreted equimolar amounts of immunoreactive CAP and calcitonin under basal (1 mM Ca/sup 2 +/) and stimulated (4 mM Ca/sup 2 +/ and 1 ..mu..M glucagon) conditions. These data indicate that the thyroidal peptide is probably the hexadecapeptide CAP which is derived from the same translation product as calcitonin. The similarity between the processing of precursors to the amidated peptide melanocyte-stimulating hormone and the corticotropin-like intermediate lobemore » peptide and processing of calcitonin and CAP suggests that the sequence Gly-Lys-Lys-Arg is one amidation codon in mammalian systems.« less |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
