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

• DOI: 10.1042/bj1410427
• Publication Date: 2015-08-10T19:54:15Z
• Authors: Philip J. Lowry; Hugh P. J. Bennett; Colin McMartin; Alexander P. Scott
• Keywords: Lobe

An adrenocorticotrophic hormone (ACTH) was isolated from extracts of the pars distalis pituitary dogfish Squalus acanthias by gel filtration and ion-exchange chromatography. It had 15% potency human ACTH in promoting cortico-steroidogenesis rat adrenal cells. Sequence analysis revealed it to be a nonatria-contapeptide with 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 identical proposed structure α-melanocyte-stimulating (α-MSH). On comparison eleven amino acid differences were seen, nine which are 20–39 region molecule is not essential for steroidogenic activity ACTH. A peptide 18–39 portion this new similarly neurointermediate lobe where considerable amounts α-MSH found. This supported our view that as well having distinct biological role its own also precursor α-MSH.