Purification of two secretin-releasing peptides structurally related to phospholipase A2 from canine pancreatic juice.
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.
Chang
T M
TM
Konar Center for Digestive and Liver Diseases, Department of Medicine, University of Rochester School of Medicine and Dentistry, New York 14642, USA. ta-min_chang@urmc.rochester.edu
Lee
K Y
KY
Chang
C H
CH
Li
P
P
Song
Y
Y
Roth
F L
FL
Chey
W Y
WY
D000595:Amino Acid Sequence; D000818:Animals; D001681:Biological Assay; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D004285:Dogs; D008969:Molecular Sequence Data; D010189:Pancreatic Juice / Q000737:chemistry*; D010741:Phospholipases A / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D054467:Phospholipases A2; D051381:Rats; D012633:Secretin / Q000378:metabolism; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D013552:Swine
D012633:Secretin; D010741:Phospholipases A; D054467:Phospholipases A2