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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.