Fig. 1

Screening of ω-transaminases from different sources and the determination of the enzymatic activity. A He-ωTA (H. elongate) and Cv-ωTA (C. violaceum) expression by SDS-PAGE analysis of whole cell (WC), purified enzymes (P), and protein marker (M). B Validation of the enzymatic activity of ω-transaminase catalyzing the conversion of cinnamaldehyde to cinnamamine. The substrate cinnamaldehyde and 2-(4-nitrophenyl)ethan-1-amine hydrochloride undergo transamination under the action of ω-transaminase to form an imine, and its tautomer produces a red precipitate. The activity of transaminase is reflected by the color change of the chromogenic reaction. C Determination of He-ωTA and Cv-ωTA conversion. Buffer without enzyme solution was added as a control. Data represent the mean ± SD (error bars) from three independent experiments