Table 2. Kinetic parametersa of recombinant laccases on benchmark substrates (mean ± SD).
Lcc4A | Lcc5 | Lcc7 | Lcc1A | Lcc1B | |||||||||||
Substrate | Km (µM) | Vmax (U mg−1)b | Vmax/Km (U mg−1 M−1)b | Km (µM) | Vmax (U mg−1)b | Vmax/Km (U mg−1 M−1)b | Km (µM) | Vmax (U mg−1)b | Vmax/Km (U mg−1 M−1)b | Km (µM) | Vmax (U mg−1)b | Vmax/Km (U mg−1 M−1)b | Km (µM) | Vmax (U mg−1)b | Vmax/Km (U mg−1 M−1)b |
ABTS | 11.2±0.9 | 0.61±0.01 | (5.44±0.31)×104 | 325±47 | 2.26±0.36 | (6.94±0.16) ×103 | 36.3±1.9 | 19.7±0.6 | (5.43±0.23) ×105 | 14.3±1.9 | 2.65±0.65 | (1.92±0.75)×105 | 42.5±10.3 | 5.61±2.26 | (1.28±0.22)×105 |
CAT | 255±76 | 0.91±0.11 | (3.72±0.75)×103 | 6280±680 | 2.65±0.10 | (4.24±0.31) ×102 | 38800±5300 | 0.53±0.05 | 13.8±0.08 | 2030±140 | 0.62±0.13 | (3.08±0.85)×102 | 3540±230 | 0.94±0.31 | (2.69±0.95)×102 |
DMP | 26.0±2.4 | 0.26±0.03 | (1.00±0.03)×104 | 113±8 | 0.60±0.03 | (5.30±0.28) ×103 | 12000±1000 | 1.73±0.09 | (1.44±0.05) ×102 | 120±4 | 1.08±0.24 | (8.94±1.79)×103 | 115±17 | 1.41±0.52 | (1.20±0.29)×104 |
DOPA | 1040±150 | 1.07±0.10 | (1.03±0.05)×103 | 10500±700 | 1.66±0.15 | (1.58±0.07) ×102 | n.a.c | n.a. | n.a. | 4550±570 | 0.49±0.19 | (1.06±0.28)×102 | 5520±850 | 0.65±0.15 | (1.22±0.45)×102 |
GUA | 648±105 | 0.16±0.01 | (2.46±0.27)×102 | 1270±90 | 0.32±0.01 | (2.57±0.17) ×102 | 8630±2120 | 0.18±0.05 | 21.4±0.3 | 943±58 | 0.73±0.13 | (7.85±1.72)×102 | 913±68 | 0.96±0.25 | (1.07±0.35)×103 |
SGZ | n.d.d | 0.09±0.01 | n.d. | n.d. | 0.02±0.00 | n.d. | n.d. | 2.52±0.81 | n.d. | n.d. | 0.98±0.20 | n.d. | n.d. | 0.75±0.07 | n.d. |
TYR | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. |
Apparent values. Parameters of Lcc1A and Lcc1B were obtained from our previous study [2].
One U was defined as the number of µmol of respective oxidized product formed in one minute under standard assay condition.
No measurable activity.
Not determined.