Skip to main content

Table 3 Steady-state kinetic constants (Km (μM), Kcat (s −1), kcat/Km (M−1 s−1)) for the oxidation of ABTS, DMP and RB 19 by Il-DyP4 and the W264 variants

From: Revealing two important tryptophan residues with completely different roles in a dye-decolorizing peroxidase from Irpex lacteus F17

 

Kinetic constantsa

Il-DyP4c

W264F c

W264H c

W264R c

W264Y c

ABTS

Km

67.29 ± 13.05

71.87 ± 20.86

68.90 ± 14.06

19.47 ± 4.41

62.30 ± 14.99

kcat

790 ± 56.06

384.85 ± 42.27

684.34 ± 52.02

52.78 ± 2.86

243.13 ± 23.59

kcat/Km

(1.17 ± 0.43) × 107

(5.35 ± 2.02) × 106

(9.93 ± 3.70) × 106

(2.71 ± 0.65) × 106

(3.90 ± 1.57) × 106

DMP

Km

8.98 ± 1.02

229.05 ± 30.78

42.64 ± 6.32

1082.00 ± 283.00

953.00 ± 102.70

kcat

58.99 ± 0.45

71.21 ± 2.60

54.29 ± 1.08

18.28 ± 2.30

56.25 ± 2.81

kcat/Km

(6.57 ± 0.44) × 106

(3.11 ± 0.84) × 105

(1.27 ± 0.17) × 106

(1.69 ± 0.81) × 104

(5.90 ± 2.74) × 104

RB19

Km

139.87 ± 42.85

27.60 ± 7.70

66.50 ± 25.31

b

b

kcat

187.90 ± 37.00

46.11 ± 5.91

86.87 ± 19.20

b

b

kcat/Km

(1.34 ± 0.86) × 106

(1.67 ± 0.76) × 106

(1.31 ± 0.76) × 106

b

b

  1. aAll data were fitted using the hyperbola function by Origin
  2. bNot detected
  3. cSubstrate oxidation was measured at pH 3.5 (10 mM sodium tartrate buffer) using 3.3 nM of enzyme concentration obtained from a molar extinction coefficient