Purification of two secretin-releasing peptides structurally related to phospholipase A2 from canine pancreatic juice

Pancreas. 1999 Nov;19(4):401-5. doi: 10.1097/00006676-199911000-00012.


We previously showed that canine pancreatic juice contains a secretin-releasing factor activity. In this study, we carried out isolation of two secretin-releasing peptides (SRPs) from canine pancreatic juice. Through ultrafiltration, anion and cation exchange, and reverse-phase high-performance liquid chromatography (HPLC) steps and an in vitro bioassay in STC-1 cells, two SRPs, SRP-1 and SRP-2, were isolated and purified to homogeneity. Both SRPs dose-dependently stimulated secretin release from STC-1 cells. The results of mass spectral analysis indicated that SRP-1 and SRP-2 had molecular masses of 14,061 Da and 14,053 Da, respectively. N-terminal amino acid sequence analysis indicated that SRP-1 was identical to canine pancreatic PLA2 in the 25 residues determined; whereas SRP-2 had 71% sequence homology to the enzyme in the first 21 residues. Commercially available porcine pancreatic PLA2 dose-dependently stimulated secretin release from STC-1 cells. Porcine pancreatic PLA2 also stimulated secretin release from a secretin-producing cells-enriched preparation isolated from rat duodenal mucosa. These results suggest that pancreatic PLA2 and its related peptide may participate in regulation of secretin secretion.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Biological Assay
  • Cell Line
  • Chromatography, High Pressure Liquid
  • Dogs
  • Molecular Sequence Data
  • Pancreatic Juice / chemistry*
  • Phospholipases A / chemistry*
  • Phospholipases A / isolation & purification*
  • Phospholipases A / pharmacology
  • Phospholipases A2
  • Rats
  • Secretin / metabolism
  • Sequence Analysis, Protein
  • Sequence Homology, Amino Acid
  • Swine


  • Secretin
  • Phospholipases A
  • Phospholipases A2