Structural characterization of peptides derived from prosomatostatins I and II isolated from the pancreatic islets of two species of teleostean fish: the daddy sculpin and the flounder

J. Michael CONLON, Michael S. DAVIS, Sture FALKMER, Lars THIM

Research output: Contribution to journalArticlepeer-review

45 Citations (Scopus)

Abstract

The primary structures of three peptides from extracts from the pancreatic islets of the daddy sculpin (Cottus scorpius) and three analogous peptides from the islets of the flounder (Platichthys flesus), two species of teleostean fish, have been determined by automated Edman degradation. The structures of the flounder peptides were confirmed by fast‐atom bombardment mass spectrometry. The peptides show strong homology to residues (49–60), (63–96) and (98–125) of the predicted sequence of preprosomatostatin II from the anglerfish (Lophius americanus). The amino acid sequences of the peptides suggest that, in the sculpin, prosomatostatin II is cleaved at a dibasic amino acid residue processing site (corresponding to Lys61–Arg62 in anglerfish preprosomatostatin II). The resulting fragments are further cleaved at monobasic residue processing sites (corresponding to Arg48 and Arg97 in anglerfish preprosomatostatin II). In the flounder the same dibasic residuc processing site is utilised but cleavage at different monobasic sites takes place (corresponding to Arg50 and Arg97 in anglerfish preprosomatostatin II). A peptide identical to mammalian somatostatin‐14 was also isolated from the islets of both species and is presumed to represent a cleavage product of prosomatostatin I.

Original languageEnglish
Pages (from-to)647-652
Number of pages6
JournalEuropean Journal of Biochemistry
Volume168
Issue number3
DOIs
Publication statusPublished - Nov 1987
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry

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