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.

EnzymeSubstrateProductKmkcatkcat/Km
µms−1mm−1 s−1
LeSAT1ShikoninAcetylshikonin159 ± 250.185 ± 0.0311.23 ± 0.32
Acetyl-CoAAcetylshikonin53 ± 40.093 ± 0.0171.77 ± 0.27
Isobutyryl-CoAIsobutyrylshikonin78 ± 180.083 ± 0.0181.07 ± 0.11
Isovaleryl-CoAIsovalerylshikonin39 ± 50.048 ± 0.0071.24 ± 0.13
LeAAT1AlkanninAcetylalkannin54 ± 130.68 ± 0.2712.7 ± 4.4
Acetyl-CoAAcetylalkannin92 ± 390.94 ± 0.3011.9 ± 3.6
Isobutyryl-CoAIsobutyrylalkannin116 ± 600.78 ± 0.307.87 ± 2.5
Isovaleryl-CoAIsovalerylalkannin20 ± 70.14 ± 0.049.72 ± 4.1