title: Somatostatins of the channel catfish.
abstract: Pancreatic tissue of the channel catfish (Ictalurus punctatus) contains two somatostatins. The amino acid sequence of a 14-residue containing peptide (SS-14) is identical in sequence and has the same mass ion by fast atom bombardment mass spectrometry as mammalian SS-14. A 22-residue somatostatin (SS-22) has also been isolated and its amino acid sequence determined. The amino acid sequence differs from that reported by Oyama et al. (J Biol Chem 255:2251, 1980) in two of the 22-residues (positions 5 and 19). Somatostatin-22 is a glycoprotein, with carbohydrate attached at Thr-5. Several 22-residue peptides have been purified and all of them have identical amino acid compositions and different carbohydrate structure and/or composition. SS-22 has 7 amino acid residues which are identical to those observed in SS-14. The nucleotide sequence of the two cDNAs coding for SS-14 and SS-22 have been determined. The mRNAs encode precursors to SS-14 and SS-22 of 114 and 105 residues, respectively. The two precursors also have different amino acid sequence at the site of prohormone proteolytic processing. Analysis of genomic DNA reveals that SS-14 and SS-22 sequences are present on different restriction fragments and thus are encoded by separate genes.
authors.forename: J E
authors.initials: JE
authors.lastname: Dixon
authors.forename: P C
authors.initials: PC
authors.lastname: Andrews
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002241:Carbohydrates / Q000032:analysis; D003001:Cloning, Molecular; D005399:Fishes / Q000502:physiology*; D013058:Mass Spectrometry; D011498:Protein Precursors / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics; D013004:Somatostatin / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D013329:Structure-Activity Relationship
chemical_list: D002241:Carbohydrates; D011498:Protein Precursors; D012333:RNA, Messenger; D013004:Somatostatin