title: Synthesis of cholecystokinin peptide CCK-4 exclusively by enzymatic methods.
abstract: The synthesis of CCK-4 (H-Trp-Met-Asp-Phe-NH2) by using enzymes exclusively was described. As protection group for the amino group we used the Phenylacetyl group (Phac) which had been cleaved at the end of the synthesis with Penicillin G Amidase (PGA) without affecting the peptide bonds. Thus, beginning with Phac-Trp-OH we had successfully synthesized the target peptide with following 4 enzymes, alpha-Chymotrypsin, Papain, Thermolysin and PGA in four reaction steps. All reactions were carried out in aqueous buffer in reasonable yields (> 65%). FAB-MS or FD-MS verified the correct molecular mass of all peptides.
authors.affiliation: School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030.
authors.forename: Zimin
authors.initials: Z
authors.lastname: Lü
authors.forename: Li
authors.initials: L
authors.lastname: Guo
authors.forename: Dietmar
authors.initials: D
authors.lastname: Huettner
authors.forename: Heiner
authors.initials: H
authors.lastname: Eckstein
mesh_terms: D002918:Chymotrypsin; D004800:Enzymes, Immobilized; D010206:Papain; D010455:Peptides; D013758:Tetragastrin / Q000138:chemical synthesis*; D013820:Thermolysin
chemical_list: D004800:Enzymes, Immobilized; D010455:Peptides; D013758:Tetragastrin; D002918:Chymotrypsin; D010206:Papain; D013820:Thermolysin