Table 1. Steady-state kinetic parameters of the recombinant RdPT1 and the A149Q mutant enzyme

Data are presented as means ± sd of three technical replicates.

EnzymeSubstrate (Cosubstrate)Apparent Affinity (Km)Catalytic Rate (Vmax)Catalytic Efficiency (Vmax/Km)
μmpmol s−1 mg−1 microsomal proteinpmol s−1 mg−1 microsomal protein μm−1
RdPT1OSA (FPP)47.0 ± 7.4140 ± 93.00 ± 0.27
GPP (OSA)224 ± 4436.9 ± 5.60.17 ± 0.01
FPP (OSA)10.0 ± 2.795.0 ± 2.89.94 ± 2.61
GGPP (OSA)4.16 ± 2.112.26 ± 0.150.65 ± 0.33
RdPT1 A149QOSA (FPP)90.5 ± 5.145.1 ± 1.10.47 ± 0.02
GPP (OSA)247 ± 498.63 ± 1.220.035 ± 0.003
FPP (OSA)9.70 ± 3.8239.6 ± 3.14.71 ± 1.67
GGPP (OSA)33.7 ± 5.01.08 ± 0.040.032 ± 0.004