title: Isolation and structures of alligator gar (Lepisosteus spatula) insulin and pancreatic polypeptide.
abstract: Insulin and a 36-residue peptide with homology to pancreatic polypeptide (PP) were isolated from the endocrine pancreas of the alligator gar (Lepisosteus spatula), a ganoid fish, by gel filtration and HPLC. Heterologous radioimmunoassays were used to detect insulin-like and PP-like immunoreactivities during purification of the two peptides. The sequence of the 36-amino acid peptide containing a C-terminal tyrosinamide was identical at 31 of 36 positions to porcine neuropeptide Y (NPY). The amino acid sequence of this peptide is YPPKPENPGEDAPPEELAKYYSALRHYINLITRQRY-NH2. The second peptide, gar insulin, contains 52 amino acid residues and is composed of a 21-residue A chain and a 31-residue B chain. The sequence of the A chain is GIVEQCCHKPCTIYELENYCN. The sequence of the B chain is AANQHLCGSHLVEALYLVCGEKGFFYNPNKV.
authors.affiliation: Veterans Administration Medical Center, Kansas City, Missouri 64128.
authors.forename: H G
authors.initials: HG
authors.lastname: Pollock
authors.forename: J R
authors.initials: JR
authors.lastname: Kimmel
authors.forename: J W
authors.initials: JW
authors.lastname: Hamilton
authors.forename: J B
authors.initials: JB
authors.lastname: Rouse
authors.forename: K E
authors.initials: KE
authors.lastname: Ebner
authors.forename: V
authors.initials: V
authors.lastname: Lance
authors.forename: A B
authors.initials: AB
authors.lastname: Rawitch
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005399:Fishes / Q000502:physiology*; D007328:Insulin / Q000302:isolation & purification*; D007515:Islets of Langerhans / Q000032:analysis*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010191:Pancreatic Polypeptide / Q000302:isolation & purification*; D010446:Peptide Fragments / Q000032:analysis; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D007328:Insulin; D046911:Macromolecular Substances; D010446:Peptide Fragments; D010191:Pancreatic Polypeptide