title: Optimization of enzyme-mediated peptide bond formation.
abstract: Enzyme-catalyzed peptide bond formation requires thorough examination and optimization of each coupling step. In order to identify factors influencing the selectivity between aminolysis and hydrolysis, a systematic study was carried out for the kinetically controlled peptide synthesis. The reaction temperature, the type of C-terminal protecting group, and different organic cosolvents showed little influence on the selectivity. The enzyme, excess nucleophile, pH, N-terminal protecting group, and ionic strength of the solution were identified as major factors controlling the selectivity and, therefore, the yield of the dipeptide synthesis. Under optimized conditions, the selectivity of the chymotrypsin-catalyzed synthesis of PheSer could be increased from 35 to 100%.
authors.affiliation: Institut für Biotechnologie, Jülich, Federal Republic of Germany.
authors.forename: A
authors.initials: A
authors.lastname: Schwarz
authors.forename: D
authors.initials: D
authors.lastname: Steinke
authors.forename: M R
authors.initials: MR
authors.lastname: Kula
authors.forename: C
authors.initials: C
authors.lastname: Wandrey
mesh_terms: D002268:Carboxypeptidases / Q000378:metabolism; D002384:Catalysis; D002918:Chymotrypsin / Q000378:metabolism; D004151:Dipeptides / Q000096:biosynthesis*; D004798:Enzymes / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D009994:Osmolar Concentration; D010206:Papain / Q000378:metabolism; D010649:Phenylalanine / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D013696:Temperature
chemical_list: D004151:Dipeptides; D004798:Enzymes; D012694:Serine; D010649:Phenylalanine; D002268:Carboxypeptidases; C022633:serine carboxypeptidase; D002918:Chymotrypsin; D010206:Papain