Skip to main content

Table 2 Kinetic parameters of the alkaline serine protease DHAP and its variants at different temperaturesa

From: Engineering Bacillus pumilus alkaline serine protease to increase its low-temperature proteolytic activity by directed evolution

Variants

15 Â°C

50 Â°C

Km (mM)

k cat

kcat/Km

(s− 1·M− 1)

Fold

(â—Š)

Km (mM)

k cat

kcat/Km

(s− 1·M− 1)

Fold

(â—Š)

(s−1)

(s−1)

wt

0.16 Â± 0.02

102 Â± 03

0.64E × 106

1.00

0.23 Â± 0.018

609 Â± 14

2.65E × 106

1.00

P9S

0.41 Â± 0.09

362 Â± 43

0.88E × 106

1.37

0.43 Â± 0.045

829 Â± 81

1.97E × 106

0.74

A1G/K27Q

0.20 Â± 0.04

373 Â± 27

1.87E × 106

2.92

0.36 Â± 0.081

1719 Â± 161

4.78E × 106

1.83

A38V

0.13 Â± 0.02

176 Â± 11

1.35E × 106

2.11

0.20 Â± 0.096

952 Â± 123

4.76E × 106

1.79

A116T

0.22 Â± 0.05

262 Â± 22

1.19E × 106

1.86

0.25 Â± 0.040

778 Â± 71

3.11E × 106

1.17

T162I

0.17 Â± 0.03

300 Â± 20

1.76E × 106

2.75

0.26 Â± 0.026

1149 Â± 53

4.41E × 106

1.66

S182R

0.19 Â± 0.03

259 Â± 18

1.36E × 106

2.13

0.23 Â± 0.50

897 Â± 102

3.90E × 106

1.47

T351S

0.31 Â± 0.05

283 Â± 24

0.91E × 106

1.42

0.25 Â± 0.053

989 Â± 97

3.96E × 106

1.49

P9S/T162I

0.30 Â± 0.013

450 Â± 10.2

1.50E × 106

2.34

0.26 Â± 0.009

1169 Â± 22

4.50E × 106

1.70

P9S/K27Q

0.35 Â± 0.035

645 Â± 28.5

1.84E × 106

2.88

0.32 Â± 0.015

1555 Â± 40

4.86E × 106

1.83

K27Q/T162I

0.21 Â± 0.013

288 Â± 5.9

1.37E × 106

2.14

0.25 Â± 0.018

1092 Â± 22

4.37E × 106

1.65

P9S/K27Q/T162I

0.34 Â± 0.016

579 Â± 19.9

1.70E × 106

2.65

0.34 Â± 0.016

1596 Â± 47

4.69E × 106

1.77

  1. aThe hydrolytic reaction was performed in 20 mM Tris-HCl buffer (pH 8.0) containing 2 mM CaCl2 with 0.05–1.2 mM AAPF-pN as substrate and 50 ng (at 15 Â°C) or 25 ng (at 50 Â°C) of enzyme
Back to article page

BMC Biotechnology

ISSN: 1472-6750

Contact us