Figure 3.

Activity assays for the screening of novel transaminases (a) by formation of a blue copper complex with the produced α-amino acid, (b) by withdrawal of the produced pyruvate in a multi-enzymatic one-pot reaction system which ultimately leads to a pH drop, (c) by direct measurement of the absorbance of acetophenone produced from the transamination of α-methylbenzylamine, (d) by measuring the decrease in conductivity which results from the conversion of the two charged substrates to the uncharged/zwitterionic products and (e) by oxidation of the produced alanine which ultimately leads to the oxidation of the dye pyrogallol red by H₂O₂ in a multi-enzymatic one-pot reaction system. Abbreviations: LDH = lactate dehydrogenase, GDH = glucose dehydrogenase, AAO = amino acid oxidase, HRP = horse radish peroxidase.