β-Endorphin-Related Peptides in the Pituitary Gland: Isolation, Identification and Distribution
| Autor: | D. E. Massey, S. Zakarian, J. F. W. Deakin, Derek G. Smyth |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
chemistry.chemical_classification
medicine.hormone endocrine system Pituitary gland Prohormone Lipotropin Peptide Pars intermedia Peptide hormone medicine.anatomical_structure chemistry Anterior pituitary Biochemistry medicine Endorphins hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | Ciba Foundation Symposium 81-Peptides of the Pars Intermedia |
| DOI: | 10.1002/9780470720646.ch6 |
| Popis: | A new procedure is described for isolation of four forms of beta-endorphin from bovine pituitary. The four peptides are: the C-fragment of lipotropin (bovine lipotropin residues 63-93, or beta-endorphin, the alpha, N-acetyl derivative of the C-fragment, the C'-fragment (bovine lipotropin residues 63-89) and the alpha, N-acetyl derivative of the C'-fragment. Of these peptides, beta-endorphin alone possesses potent analgesic activity. The procedure has been applied in studying the distribution of beta-endorphin-related peptides in two regions of the pituitary. The results show that in the anterior pituitary of the pig and the rat, beta-endorphin is produced with a high degree of specificity in its opiate active form. In contrast, in the pars intermedia of both species at least six peptides related to beta-endorphin are elaborated and beta-endorphin represents only a minor component. The principal peptides in the pars intermedia have been identified as acetylated derivatives of lipotropin C'-fragment: in the pig the predominant peptide is alpha,N-acetyl C'-fragment and in the rat the major peptide appears to be an epsilon-acetylated derivative of alpha,N-acetyl C'-fragment. Thus, beta-endorphin is activated in the anterior pituitary and inactivated in the pars intermediate. The results demonstrate selective and specific processing of the 31K ACTH-endorphin prohormone in the different regions of the pituitary. In the anterior pituitary two biologically active peptides, ACTH and beta-endorphin, are generated together; in the pars intermedia alpha-melanotropin (alpha-MSH) is accompanied by forms of beta-endorphin that have been inactivated by acetylation and proteolysis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|