title: The isolation and amino acid sequence of an adrenocorticotrophin from the pars distalis and a corticotrophin-like intermediate-lobe peptide from the neurointermediate lobe of the pituitary of the dogfish Squalus acanthias.
abstract: An adrenocorticotrophic hormone (ACTH) was isolated from extracts of the pars distalis of the pituitary of the dogfish Squalus acanthias by gel filtration and ion-exchange chromatography. It had 15% of the potency of human ACTH in promoting cortico-steroidogenesis in isolated rat adrenal cells. Sequence analysis revealed it to be a nonatria-contapeptide with the following primary structure: Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Met-Gly-Arg-Lys-Arg-Arg-Pro-Ile-Lys-Val-Tyr-Pro-Asn-Ser-Phe-Glu-Asp-Glu-Ser-Val-Glu-Asn-Met-Gly-Pro-Glu-Leu. The N-terminal tridecapeptide sequence was identical with the proposed structure of dogfish alpha-melanocyte-stimulating hormone (alpha-MSH). On comparison with human ACTH eleven amino acid differences were seen, nine of which are in the 20-39 region of the molecule which is not essential for the steroidogenic activity of ACTH. A peptide identical with the 18-39 portion of this new ACTH was similarly isolated from the neurointermediate lobe of the pituitary where considerable amounts of dogfish alpha-MSH were found. This supported our view that ACTH as well as having a distinct biological role of its own is also the precursor of alpha-MSH.
mesh_terms: D000305:Adrenal Cortex Hormones / Q000096:biosynthesis; D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives / Q000032:analysis* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D001322:Autoanalysis; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004284:Dogfish; D009074:Melanocyte-Stimulating Hormones / Q000032:analysis / Q000096:biosynthesis; D009994:Osmolar Concentration; D010902:Pituitary Gland / Q000032:analysis*; D010904:Pituitary Gland, Posterior / Q000032:analysis*; D012754:Sharks
chemical_list: D000305:Adrenal Cortex Hormones; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones