Table 3.

Kinetic parameters of LlAdhA variants on related aldehydes.

Aldehydes	LlAdhA			LlAdhA^RE1			LlAdhA^29C8

	K_M [mM]	k_cat [s^−1]	kcat/K_M [mM⁻¹s⁻¹]	K_M [mM]	k_cat [s^−1]	kcat/K_M [mM⁻¹s⁻¹]	K_M [mM]	k_cat [s^−1]	kcat/K_M [mM⁻¹s⁻¹]
Isobutyraldehyde	12	30	2.8	1.70	140	82	0.68	300	440
Acetaldehyde	0.4	35	94	0.5	31	57	0.92	58	63
5-HMF	22	19	0.88	0.67	23	34	0.57	29	51
2-Furaldehyde	0.39	22	57	0.26	6.0	21	0.20	7	37
Cinnamaldehyde	0.7	27	39	0.24	28	140	0.16	31	210

All enzymes were purified prior to characterization. Errors are reported as standard deviations determined from a minimum of three independent experiments. The resulting standard errors are shown in Table S3, Supplemental Information. The enzyme assays were conducted in 100 mM Tris pH 7 with 1 mM DTT, 200 µM NADH, and 10 mM substrate. Concentrations of the purified enzymes were determined using the Bradford assay. The Michaelis-Menten constants for the substrate were measured with appropriate dilution series of isobutyraldehyde. Enzyme assays were performed at 25°C.