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Table 1 Catalytic parameters and expression levels of wild-type and CotA mutants.

From: Improving the functional expression of a Bacillus licheniformislaccase by random and site-directed mutagenesis

Enzyme variant

KM (μM)a

Specific activity (μmol min-1 mg-1)a

Catalytic efficiency (μmol min-1 mg-1 μM-1)

Volumetric activity

(U l-1)a

Protein yield

(mg l-1)b

Improvement factor

CotA

6.5 ± 0.2

16.0 ± 0.2

2.46

410 ± 10

26

1

D500G

9.5 ± 0.2

11.1 ± 0.1

1.17

2200 ± 200

199

7.8

K316N

10.0 ± 0.3

14.0 ± 0.2

1.40

1100 ± 100

79

3.1

K316N/D500G

8.4 ± 0.2

11.7 ± 0.2

1.39

3400 ± 100

291

11.4

  1. a Determined using ABTS as substrate in 0.1 M citrate/phosphate buffer, pH 4.0. Each value was calculated from three independent experiments.
  2. b Calculated on the basis of volumetric activity and specific activity of each laccase variant.