Characterization of a Somatostatin-28 Containing the (Tyr-7, Gly-10) Derivative of Somatostatin-14: A Terminal Active Product of Prosomatostatin II Processing in Anglerfish Pancreatic Islets

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 81; no. 22; pp. 7003 - 7006
• Main Authors: Morel, Alain, Gluschankof, Pablo, Gomez, Sophie, Fafeur, Veronique, Cohen, Paul
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 01.11.1984; National Acad Sciences
• Subjects: Amino Acid Sequence; Amino acids; Animals; Anterior pituitary; Antiserum; Biochemistry; Complementary DNA; Elution; Fishes; Growth hormones; Islets of Langerhans; Messenger RNA; Protein Precursors - metabolism; Protein Processing, Post-Translational; Rats; Somatostatin - biosynthesis; Somatostatin - immunology; Somatostatin - metabolism; Somatostatin-28
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.81.22.7003

Anglerfish (Lophius piscatorius) Brockmann organs contain a form of somatostatin-14, identical to the hypothalamic tetradecapeptide, and two distinct forms of somatostatin-28, which can be separated by reversed-phase high-pressure liquid chromatography (HPLC). Analysis of the NH2-terminal amino acid sequence and comparison of the ability to incorporate125I indicate that one of these forms corresponds to an octacosapeptide including in its sequence the (Tyr-7, Gly-10) derivative of somatostatin-14 (somatostatin II). Exposure of this somatostatin-28 species to an endopeptidase activity from the rat brain cortex generates a peptide immunologically related to somatostatin and undistinguishable from synthetic (Tyr-7, Gly-10) somatostatin-14 II by HPLC. This somatostatin-28 II exhibits a potent inhibitory effect on growth hormone release by rat anterior pituitary cells, comparable to the other somatostatin-28 form. Since (Tyr-7, Gly-10) somatostatin-14 II cannot be detected in anglerfish pancreatic islets, these results indicate that somatostatin-28 II represents the terminal active product of prosomatostatin II processing, whose structure was predicted from the cDNA nucleotide sequence corresponding to the second mRNA cloned from anglerfish Brockmann organs [Hobart, P., Crawford, R., Shen, L. P., Pictet, R. & Rutter, W. J. (1980) Nature (London) 288, 137-141].