title: Studies on peptides. LXXXVII. Synthesis of an octacosapeptide amide corresponding to the entire amino acid sequence of chicken vasoactive intestinal polypeptide (VIP).
abstract: The octacosapeptide amide corresponding to the entire amino acid sequence of chicken VIP was synthesized in a conventional manner, using a new arginine derivative, NG-mesitylene-2-sulfonylarginine, Arg(Mts). Treatment of a fragment, Z(OMe)-Thr-Asp-Asn-Tyr-NHNH2 with methanesulfonic acid or HBr was found to give a product with a low recovery of Asp, after aminopeptidase digestion. Ring closure of the Asp-Asn unit seemed to be responsible for this phenomenon. Deprotection with HF or TFA exhibited definitely less such a tendency. In the final step of the synthesis, all protecting groups, including the Mts group, were removed by HF in the presence of m-cresol and the deprotected peptide was purified by ion-exchange chromatography on CM-cellulose followed by isoelectric focusing in Ampholine pH 9--1. Synthetic peptide exhibited the identical Rf value with that of natural chicken VIP and was active as the natural peptide.
mesh_terms: D000577:Amides / Q000138:chemical synthesis* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives; D002645:Chickens; D002852:Chromatography, Ion Exchange; D005768:Gastrointestinal Hormones / Q000138:chemical synthesis*; D007525:Isoelectric Focusing; D010446:Peptide Fragments; D014660:Vasoactive Intestinal Peptide / Q000138:chemical synthesis* / Q000302:isolation & purification
chemical_list: D000577:Amides; D005768:Gastrointestinal Hormones; D010446:Peptide Fragments; D014660:Vasoactive Intestinal Peptide; D001120:Arginine