title: Pepsin-catalyzed peptide synthesis in biphasic systems.
abstract: Pepsin catalyzed peptide synthesis in biphasic systems containing more than 95% (v/v) of organic phase was studied. Good yields were only obtained with more hydrophobic solvents, in spite of the low solubility of the substrates. The effects of the following parameters were also investigated: concentration of amino and carboxylic components, pH and buffer concentration, ratio between the aqueous and organic phases. The influence of different amino acid residues in the P2 position was investigated through the coupling between Z-Xyz-Phe-OH (where Xyz = Ala, Phe, Trp and Tyr) and Phe-OMe.
authors.affiliation: Department of Biochemistry, University of Sao Paulo, Brazil.
authors.forename: M P
authors.initials: MP
authors.lastname: Bemquerer
authors.forename: F C
authors.initials: FC
authors.lastname: Theobaldo
authors.forename: M
authors.initials: M
authors.lastname: Tominaga
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D004151:Dipeptides / Q000138:chemical synthesis / Q000737:chemistry; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry; D010434:Pepsin A / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D012995:Solubility; D012997:Solvents; D014867:Water
chemical_list: D004151:Dipeptides; D009842:Oligopeptides; D010455:Peptides; D012997:Solvents; D014867:Water; C051209:N-(benzyloxycarbonyl)phenylalanylphenylalanine methyl ester; D010434:Pepsin A