Table 2

Kinetic properties of PpAOS2 with different hydroperoxy fatty acid substrates
Substrate KM[μM] Vmax[μM/min] kcat[1/min] kcat/KM[min-1M-1× 106]
9-HPOD 36 +/− 5 0.02 +/− 0.001 5 0.14
9- HPOT(n-3) 40 +/− 4 0.01 +/− 0.001 2.5 0.06
9- HPOT(n-6) 28 +/− 4. 0.03 +/− 0.002 7.5 0.27
13-HPOD 27+/− 3 0.04 +/− 0.002 10 0.37
13- HPOT(n-3) 30 +/− 5 0.02 +/− 0.002 5 0.17
13- HPOT(n-6) 42 +/− 10 0.02 +/− 0.002 5 0.12
12-HPETE 10 +/− 5 0.49 +/− 0.057 12250 1228.69

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. For analysis between 20 and 30 data points data points were fitted to the Michaelis-Menten equation. Note that the PpAOS2-concentration used for incubations with 12-HPETE was different (1 nM) from those used for incubations with the other substrates (100 nM). Kcat values are corrected to 100% heme occupancy from the ~4% 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