TABLE 2

Steady state kinetic parameters of mAOX1, mAOX3, mAOX4, and mAOX2

Steady-state kinetics were corrected to molybdenum saturation of 100%. Kinetic parameters were recorded in 50 mM Tris-HCl, 200 mM NaCl, and 1 mM EDTA (pH 8.0) in the presence of 100 μM DCPIP as electron acceptor. Data are mean values from three independent measurements (±S.D.).

SubstrateKinetic ParametersmAOX1mAOX3mAOX4mAOX2
Pyridoxalkcat (min−1)N.D.N.D.N.D.N.D.
KM (μM)
kcat / KM (min−1 × μM−1)
Vanillinkcat (min−1)449.9 ± 26.4159.5 ± 3.815.9 ± 2.280.4 ± 11.5
KM (μM)104.0 ± 17.74.6 ± 0.55.4 ± 0.52.3 ± 0.7
kcat / KM (min–1. μM−1)4.334.52.942.1
p-DMACkcat (min–1)116.2 ± 7.388.5 ± 4.830.5 ± 4.244.8 ± 3.7
KM (μM)3.3 ± 0.20.5 ± 0.10.8 ± 0.10.4 ± 0.1
kcat / KM (min–1. μM−1)34.1196.736.3125.3
N1-Methylnicotinamidekcat (min−1)N.D.19.6 ± 4.8N.D.49.1 ± 5.7
KM (μM)27.9 ± 2.59.4 ± 3.2
kcat / KM (min–1. μM−1)0.75.2
Salicylaldehydekcat (min–1)137.5 ± 2.7213.0 ± 23.4205.2 ± 6.7221.8 ± 49.7
KM (μM)89.6 ± 2.93.5 ± 0.113.2 ± 2.421.1 ± 12.0
kcat / KM (min–1. μM−1)1.560.415.610.5
Retinaldehydekcat (min−1)122.7 ± 5.146.5 ± 6.810.6 ± 1.227.9 ± 0.4
KM (μM)16.5 ± 2.432.1 ± 5.612.6 ± 2.326.4 ± 1.57
kcat / KM (min–1. μM−1)7.41.40.81.1
  • N.D., no activity was detectable