Fig. 3

Coenzyme preference of the recombinant AcCR. Reaction conditions: 0.25 mM NADH or NADPH (0.5 mM NAD⁺ or NADP⁺), 2 mL 50 mM citrate–phosphate buffer (pH 6.5 for the reduction or pH 8.0 for oxidation), and 5 mM 4′-chloroacetophenone (150 mM isopropanol) were incubated for 5 min at 35 °C before adding 20 μL purified recombinant AcCR (about 0.008 mg of the purified enzyme), and then the changes of absorbance for 3 min were recorded