AbstractThe transamination reaction of l‐phenylalanine with pyruvate as catalyzed by the artificial transaminase formed with synthetic bilayer aggregates was examined in aqueous media under mild kinetic conditions. Each catalyst system was constructed with a combination of a synthetic peptide lipid, a hydrophobic vitamin B6derivative, and metal ions. Modification of the active site in the present artificial transaminase was performed by changing a combination of molecular components constituting the catalytic system. While the catalytic activity was scarcely influenced by differences in aggregate structure, single‐ or multi‐walled bilayer, and in copper‐(II) concentration, molecular structures of the hydrophobic vitamin B6and an amino acid residue of the peptide lipid had significant effects on the rea