A novel vasoactive intestinal peptide (VIP) from elasmobranch intestine has full affinity for mammalian pancreatic VIP receptors.
A peptide that cross reacted with N-terminal, but not C-terminal, antisera to vasoactive intestinal peptide (VIP) was isolated from extracts of intestine from the dogfish Scyliorhinus canicula. Microsequence analysis gave the structure His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Ser-Arg-Ile-Arg-Lys-Gln-Met-Ala-Val-Lys - Lys-Tyr-Ile-Asn-Ser-Leu-Leu-Ala-NH2. C-terminal amidation was determined by HPLC analysis of phenylthiocarbamyl amino acid derivatives after carboxypeptidase Y digestion. The peptide differs at five positions from the porcine octacosapeptide. Dogfish VIP was equipotent with its porcine counterpart in inhibiting binding of 125I-labelled VIP to guinea pig dispersed pancreatic acini, and in stimulating amylase secretion by the same preparation. The data indicate a strong conservation of VIP during evolution and permit identification of residues crucial for bioactivity.
D000595:Amino Acid Sequence; D000681:Amylases / Q000378:metabolism; D000818:Animals; D005075:Biological Evolution; D002268:Carboxypeptidases / Q000378:metabolism; D003488:Cyanogen Bromide; D004284:Dogfish / Q000378:metabolism*; D006168:Guinea Pigs; D007422:Intestines / Q000032:analysis*; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D010446:Peptide Fragments; D011964:Receptors, Gastrointestinal Hormone / Q000378:metabolism*; D018005:Receptors, Vasoactive Intestinal Peptide; D012754:Sharks / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology
D010446:Peptide Fragments; D011964:Receptors, Gastrointestinal Hormone; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide; D000681:Amylases; D002268:Carboxypeptidases; C022633:serine carboxypeptidase; D003488:Cyanogen Bromide