title: Isolation of the tachykinin, des[Ser1Pro2]scyliorhinin II from the intestine of the ray, Torpedo marmorata.
abstract: A peptide with neurokinin A-like immunoreactivity was isolated from an extract of the intestine of an elasmobranch fish, Torpedo marmorata. The primary structure of the peptide was established as Ser-Asn-Ser-Lys-Cys-Pro-Asp-Gly-Pro-Asp-Cys-Phe-Val-Gly-Leu-Met.NH2. This amino acid sequence is identical to that of residues (3-18) of scyliorhinin II previously isolated from the intestine of the common dogfish (Scyliorhinus canicula). The presence of the truncated peptide, lacking Ser-Pro, in the Torpedo gut suggests that scyliorhinin II may be a substrate for an enzyme with dipeptidylpeptidase IV-like specificity. The data support previous assertions that strong evolutionary pressure has acted within the elasmobranch subclass of chondrichthyean fish to conserve the structures of regulatory peptides.
authors.affiliation: Clinical Research Group for Gastrointestinal Endocrinology of the Max-Planck-Gesellschaft, University of Göttingen, Federal Republic of Germany.
authors.forename: J M
authors.initials: JM
authors.lastname: Conlon
authors.forename: L
authors.initials: L
authors.lastname: Thim
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D005075:Biological Evolution; D055598:Chemical Phenomena; D002621:Chemistry; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D007422:Intestines / Q000032:analysis; D015288:Neurokinin A / Q000302:isolation & purification; D010446:Peptide Fragments / Q000302:isolation & purification*; D011863:Radioimmunoassay; D015320:Tachykinins / Q000302:isolation & purification*; D014101:Torpedo / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D010446:Peptide Fragments; D015320:Tachykinins; C057762:scyliorhinin II (3-18); D015288:Neurokinin A