Table 1

Kinetic properties of PpAOS1 with different hydroperoxy fatty acid substrates
Substrate KM[μM] Vmax[μM/min] kcat[1/min] kcat/KM[min-1M-1× 106]
9-HPOD 121 +/− 61 0.98 +/− 0.29 32680 270
9- HPOT(n-3) 39 +/− 14 0.20 +/− 0.03 6706 172
9-HPOT(n-6) 46 +/− 17 2.35 +/− 0.37 156733 3426
13-HPOD 83 +/− 42 0.96 +/− 0.27 31856 384
13-HPOT(n-3) 95 +/− 27 0.90 +/− 0.16 30070 316
13-HPOT(n-6) 107 +/− 57 2.77 +/− 0.88 184500 1731
12-HPETE 7 +/− 2 0.23 +/− 0.02 7657 1176

Kinetic properties were determined by measuring the initial time-dependent substrate consumption at 234 nm at different substrate concentrations typically ranging from 2–100 μM. In some cases the highest substrate concentration applied was 150 μM. For analysis between 20 and 30 data points were fitted to the Michaelis-Menten equation. Note that PpAOS1-concentrations used for incubations with 9- and 13-HPOT(n-6) were different (0.05 nM) from those used for incubations with the other substrates (0.1 nM). Kcat values are corrected to 100% heme occupancy from the ~30% heme content in the enzyme preparation.

Scholz et al.

Scholz et al. BMC Plant Biology 2012 12:228   doi:10.1186/1471-2229-12-228

Open Data