Biochemical characterization of a functional recombinant aryl-alcohol dehydrogenase from Taiwanofungus camphorata

Botanical Studies

Table 1 Summary of the reactions catalyzed by TcAAD

Substrate	Cofactor	Product	V (nmole of NADH/min/mg of TcAAD)
benzyl alcohol	NAD⁺	benzyl aldehyde	262.72 ± 13.15 at pH 9.6
3,4-dimethoxybenzyl alcohol	NAD⁺	veratraldehyde	290.05 ± 13.15 at pH 9.6
2,4-dimethoxybenzyl alcohol	NAD⁺	2,4-dimethoxybenzyl aldehyde	232.35 ± 12.05 at pH 9.6
4-(hydroxymethyl)benzoic acid	NAD⁺		1099.47 ± 17.05 at pH 9.6
4-(hydroxymethyl)benzoic acid	NADP⁺		No reaction at pH 9.6
veratraldehyde	NADH	3,4-dimethoxybenzyl alcohol	No reaction at pH 6
veratraldehyde	NADPH	3,4-dimethoxybenzyl alcohol	V_max = 0.014 mM/min at pH 6

Enzymatic activity (V ± SD) was measured as described in Materials and Methods in the presence of 10 μg/0.1 mL enzyme, 4 mM NAD⁺, 0.1 mM alcohol related substrates at pH 9.6. The V was measured as the increase of NADH (355 nm) in the first 0.5-1 min reaction at 25°C. The reactions with veratraldehyde substrate were carried out in the presence of 3 μg/0.1 mL enzyme, 0.2 mM NADH or 0.2 mM NADPH and 0.2 mM veratraldehyde at pH 6. The V was measured as the decrease of NADH (355 nm) or NADPH (365 nm) in the first 0.5-1 min reaction at 25°C.