Glycine-extended processing intermediate of proVIP: a new form of VIP in the rat.
The biosynthesis of many peptides including vasoactive intestinal polypeptide (VIP) requires enzymatic alpha-carboxyamidation via a glycine-extended intermediate form. In an effort to identify and quantify glycine-extended VIP in rat tissue extracts a radio-immunoassay specific for this peptide was developed. The concentrations of glycine-extended VIP ranged from 1.3 pmol/g in the brain to 83.9 pmol/g in the small intestine. The identity of the peptide was substantiated by cation-exchange HPLC. The ratio of glycine-extended VIP to amidated VIP varied considerably being highest (63%) in the small intestine. The natural occurrence of glycine-extended VIP in connection with our recent demonstration of its biological activity suggest a physiological role for this biosynthetic intermediate VIP form.
Fahrenkrug
J
J
Department of Clinical Chemistry, Bispebjerg Hospital, University of Copenhagen, Denmark.
D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry; D004064:Digestive System / Q000737:chemistry; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011498:Protein Precursors / Q000032:analysis* / Q000235:genetics; D011499:Protein Processing, Post-Translational; D011863:Radioimmunoassay; D051381:Rats; D014660:Vasoactive Intestinal Peptide / Q000032:analysis* / Q000235:genetics
D011498:Protein Precursors; C069765:vasoactive intestinal peptide, Gly-; D014660:Vasoactive Intestinal Peptide