Table 2. Steady-state kinetic parameters of the recombinant LeSAT1 and LeAAT1.

Data are means ± sd of three independently prepared samples with three technical replicates for each sample. Shikonin and alkannin were incubated with 0.25 mm of acetyl-CoA, and acyl-CoAs were incubated with 0.5 mm of shikonin or alkannin.

Enzyme	Substrate	Product	Km	kcat	kcat/Km
			µm	s−1	mm−1 s−1
LeSAT1	Shikonin	Acetylshikonin	159 ± 25	0.185 ± 0.031	1.23 ± 0.32
	Acetyl-CoA	Acetylshikonin	53 ± 4	0.093 ± 0.017	1.77 ± 0.27
	Isobutyryl-CoA	Isobutyrylshikonin	78 ± 18	0.083 ± 0.018	1.07 ± 0.11
	Isovaleryl-CoA	Isovalerylshikonin	39 ± 5	0.048 ± 0.007	1.24 ± 0.13
LeAAT1	Alkannin	Acetylalkannin	54 ± 13	0.68 ± 0.27	12.7 ± 4.4
	Acetyl-CoA	Acetylalkannin	92 ± 39	0.94 ± 0.30	11.9 ± 3.6
	Isobutyryl-CoA	Isobutyrylalkannin	116 ± 60	0.78 ± 0.30	7.87 ± 2.5
	Isovaleryl-CoA	Isovalerylalkannin	20 ± 7	0.14 ± 0.04	9.72 ± 4.1