title: Amino acid sequence of catfish pancreatic somatostatin I.
abstract: Two peptides, pancreatic somatostatins I and II, larger and more acidic than synthetic tetradecapeptide somatostatin, have been purified from pancreatic islets of channel catfish (Ictalurus punctata). These peptides have reduced immunoreactivity in a radioimmunoassay for synthetic somatostatin, but full biological activity was measured as inhibition of growth hormone released from isolated rat anterior pituitary cells. Pancreatic somatostatin I is composed of 22 amino acids. Eight additional amino acids are found as an NH2-terminal extension of the segment which is homologous to synthetic tetradecapeptide somatostatin. Seven of fourteen residues of tetradecapeptide somatostatin are present in the COOH-terminal portion of catfish pancreatic somatostatin I. The sequence is NH2-Asp-Asn-Thr-Val-Arg-Ser-Lys-Pro-Leu-Asn-Cys-Met-Asn-Tyr-Phe-Trp-Lys-Ser-Ser-Thr-Ala-Cys-COOH. There is considerable homology with the carboxyl end of synthetic tetradecapeptide somatostatin.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005399:Fishes; D007031:Hypothalamus / Q000032:analysis; D009928:Organ Specificity; D010179:Pancreas / Q000032:analysis*; D010446:Peptide Fragments / Q000032:analysis; D011863:Radioimmunoassay; D012756:Sheep; D013004:Somatostatin; D014357:Trypsin
chemical_list: D010446:Peptide Fragments; D013004:Somatostatin; D014357:Trypsin