Table 1 The kinetic parameter (±SD) of different DapDH for different substrate with NADPH or NADP⁺ as cofactor^a.

Enzymes	Cofactor	Reaction	Substrate	V_max (U/mg)	K_m (mmol/L)	K_cat (/s)	K_cat/K_m
CgDapDH	NADPH	Amination	THDPA	2.1 ± 0.3	0.27 ± 0.02	41.9 ± 4.4	155.2
	NADPH	Amination	\({{\rm{NH}}}_{4}^{+}\)	38.4 ± 3.4	39.2 ± 6.5	768.3 ± 62.5	23.8
	NADP⁺	Deamination	meso-DAP	5.8 ± 0.6	2.8 ± 0.3	115.4 ± 15.8	41.2
BsDapDH	NADPH	Amination	THDPA	3.2 ± 0.2	0.23 ± 0.05	64.7 ± 7.3	281.3
	NADPH	Amination	\({{\rm{NH}}}_{4}^{+}\)	25.6 ± 2.3	10.8 ± 1.02	511.9 ± 27.6	47.4
	NADP⁺	Deamination	meso-DAP	7.7 ± 0.5	2.4 ± 0.1	154.2 ± 0.4	64.3
CtDapDH	NADPH	Amination	THDPA	13.9 ± 0.3	0.11 ± 0.03	278.2 ± 25.3	2318.3
	NADPH	Amination	\({{\rm{NH}}}_{4}^{+}\)	90.8 ± 10.1	89 ± 14.2	1815.6 ± 125.3	205.4
	NADP⁺	Deamination	meso-DAP	17.2 ± 1.3	0.21 ± 0.05	344.3 ± 31.4	1638.6
StDapDH	NADPH	Amination	THDPA	2.7 ± 0.1	0.24 ± 0.3	52.8 ± 4.5	220.0
	NADPH	Amination	\({{\rm{NH}}}_{4}^{+}\)	19.4 ± 2.6	6.3 ± 0.7	387.4 ± 45.3	61.5
	NADP⁺	Deamination	meso-DAP	7.3 ± 0.5	1.8 ± 0.08	145.7 ± 1.4	80.9
BfDapDH	NADPH	Amination	THDPA	0.24 ± 0.03	0.57 ± 0.14	4.9 ± 0.3	8.6
	NADPH	Amination	\({{\rm{NH}}}_{4}^{+}\)	8.04 ± 0.96	4.2 ± 0.5	160.8 ± 21.2	38.3
	NADP⁺	Deamination	meso-DAP	0.39 ± 0.05	0.11 ± 0.02	7.7 ± 0.4	70.0
UtDapDH	NADPH	Amination	THDPA	2.5 ± 0.1	0.26 ± 0.3	50.6 ± 4.5	194.6
	NADPH	Amination	\({{\rm{NH}}}_{4}^{+}\)	17.3 ± 2.2	6.5 ± 0.5	347.7 ± 25.8	53.4
	NADP⁺	Deamination	meso-DAP	6.2 ± 0.4	1.9 ± 0.2	123.3 ± 9.4	64.9

^aThe mixture for measuring NADPH oxidation contained 200 mmol/L Na₂CO₃-NaHCO₃ (pH 8.5), 0.5 mmol/L NADPH, 200 mmol/L NH₄Cl, 5.0 mmol/L THDPA and 25 μg of pure recombinant DapDH. The production of NADP⁺ was monitored continuously at A340. The mixture for measuring NADP⁺ reduction contained 200 mmol/L Na₂CO₃-NaHCO₃ (pH 10.0), 5 mmol/L meso-DAP, 0.5 mmol/L NADP⁺ and 25 μg of pure recombinant DapDH. The production of NADPH was monitored continuously at A340. The kinetic parameters were determined by varying substrate concentrations while keeping the co-substrate level constant at the set concentration. All assays were carried out at 30 °C.
All data are meaning values of three determinations of three independent experiments with ±SD.

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