title: N-Terminal sequence of human big gastrin: sequence, synthetic and immunochemical studies.
abstract: The previously assigned structure of human big gastrin is revised as a result of sequencing and immunological studies on synthetic peptides. A nonadecapeptide has been synthesized and found to have full immunochemical potency compared with natural human G34 in a radioimmunoassay which is specific for the N-terminal sequence. Syntheses of the peptides were achieved using the stepwise procedure with benzyloxycarbonyl-amino acids and fragment couplings mediated mainly by the dicyclohexylcarbodiimide procedure in the presence of either N-hydroxysuccinimide or 1-hydroxybenzotriazole. Purification of the peptide fragments was by Sephadex LH-20 chromatography and removal of protecting groups was effected using 90% trifluoroacetic acid in the presence of scavengers. Purification of the nonadecapeptide was achieved by high performance liquid chromatography.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids; D055598:Chemical Phenomena; D002621:Chemistry; D005755:Gastrins / Q000138:chemical synthesis*; D006801:Humans; D011498:Protein Precursors; D011863:Radioimmunoassay; D015043:Zollinger-Ellison Syndrome / Q000032:analysis
chemical_list: D000596:Amino Acids; D005755:Gastrins; D011498:Protein Precursors; C013706:big gastrin