Skip to main content

Table 5 Kinetic parameters of the purified wild-type and mutant enzymes toward oNPG as substrate

From: Effect of mutations to amino acid A301 and F361 in thermostability and catalytic activity of the β-galactosidase from Bacillus subtilis VTCC-DVN-12-01

Enzyme

Vmax (IU/mg)

Km (mM)

Kcat (s−1)

Kcat/Km s−1mM−1

Kcat/Km (%)

Wild-type LacA

2.61 ± 0.12

9.28 ± 0.72

21.74 ± 0.99

2.35 ± 0.08

100

LacA-301 V

0.76 ± 0.02

5.57 ± 0.56

3.72 ± 0.09

0.67 ± 0.08

28.65

LacA-361Y

1.03 ± 0.03

8.02 ± 0.27

8.56 ± 0.24

1.07 ± 0.01

45.50

  1. K m Michaelis constant, K cat turnover rate, K cat /K m catalytic efficiency
  2. The relative activity of β-galactosidase was determined in 100 mM buffer Z (pH 7.0) at 55 °C with oNPG as a substrate