Table 2 Effect of pH and temperature on the activity and stability of wild type and mutant phytases.

From: Engineering the residual side chains of HAP phytases to improve their pepsin resistance and catalytic efficiency

Enzyme

pH optimum

Temperature optimum (°C)

pH stability

Thermostability

Residual activity (%) a at pH 1.0 for 1 h

Residual activity (%) a at 60 °C for 30 min

Half-life (min) at 60 °C

YkAPPA

 WT

4.5

55

pH 1.0–1.5, 63.7–77.0; pH 2.0–10.0, >90.5

16.1 ± 0.41

12.5 ± 0.52

 E230G

4.5

55

pH 1.0–1.5, >92.4; pH 2.0–10.0, >99.3

34.7 ± 1.23

21.7 ± 0.82

 E230A

4.5

55

pH 1.0–1.5, >87.0; pH 2.0–10.0, >99.2

16.0 ± 0.73

12.4 ± 0.33

 E153P

4.5

60

pH 1.0–1.5, <78.0; pH 2.0–10.0, >87.8

41.7 ± 1.74

25.6 ± 0.48

 E230R

4.0

55

pH 1.0–1.5, >86.8; pH 2.0–10.0, >94.6

22.6 ± 0.83

14.5 ± 0.37

 E230S

4.5

55

pH 1.0–1.5, <78.7; pH 2.0–10.0, >89.2

33.6 ± 1.82

19.9 ± 0.77

 E230T

4.5

55

pH 1.0–1.5, <78.3; pH 2.0–10.0, >91.1

33.4 ± 2.42

19.5 ± 0.73

 E230D

4.5

55

pH 1.0–1.5, <76.5; pH 2.0–10.0, >90.8

16.5 ± 0.76

12.7 ± 0.38

 E230K

4.5

55

pH 1.0–1.5, >80.0; pH 2.0–10.0, >94.6

16.1 ± 0.63

12.5 ± 0.52

 L162V

4.5

60

pH 1.0–1.5, >83.5; pH 2.0–10.0 >93.6

30.5 ± 1.45

17.9 ± 0.39

 L162A

4.5

55

pH 1.0–1.5, >85.1; pH 2.0–10.0 >93.2

16.8 ± 0.43

12.8 ± 0.44

 L162G

4.5

55

pH 1.0–1.5, >89.9; pH 2.0–10.0 >99.7

16.6 ± 0.51

12.7 ± 0.37

 L99A

4.5

55

pH 1.0–1.5, <78.1; pH 2.0–10.0 >92.1

15.8 ± 0.48

12.1 ± 0.58

 L99A/L162G

4.5

55

pH 1.0–1.5, >90.3; pH 2.0–10.0 >99.2

16.2 ± 0.55

12.6 ± 0.62

 L99A/L162G/E230G

4.5

55

pH 1.0–1.5, >90.3; pH 2.0–10.0 >99.2

35.1 ± 1.31

21.9 ± 0.77

YeAPPA

 WT

5.0

45

pH 1.0–2.0, <12.3; pH 3.0–9.0, >88.7

0.6 ± 0.02

1.1 ± 0.04

 E230G

5.0

45

pH 1.0–2.0, >32.1; pH 3.0–9.0, >99.6

21.4 ± 0.94

13.8 ± 0.43

 E230P

5.0

50

pH 1.0–2.0, >24.3; pH 3.0–9.0, >99.4

11.5 ± 0.82

12.9 ± 0.46

 E230R

4.0

45

pH 1.0–2.0, >29.7; pH 3.0–9.0, >99.3

8.9 ± 0.04

11.3 ± 0.37

 L162V

5.0

45

pH 1.0–2.0, >13.5; pH 3.0–9.0, >92.3

9.5 ± 0.04

11.7 ± 0.42

 L162A

5.0

45

pH 1.0–2.0, >17.6; pH 3.0–9.0, >96.4

0.6 ± 0.04

1.1 ± 0.24

 L162G

5.0

45

pH 1.0–2.0, >20.1; pH 3.0–9.0, >99.4

0.6 ± 0.004

1.1 ± 0.31

 L99A

5.0

45

pH 1.0–2.0, >13.3; pH 3.0–9.0, >90.1

0.7 ± 0.004

1.1 ± 0.29

 L99A/L162G

5.0

45

pH 1.0–2.0, >21.8; pH 3.0–9.0, >99.6

0.6 ± 0.005

1.1 ± 0.27

 L99A/L162G/E230G

5.0

45

pH 1.0–2.0, >38.8; pH 3.0–9.0, >99.2

21.7 ± 0.89

13.9 ± 0.61

  1. aThe phytase activity towards sodium phytate (1.5 mM) at 37 °C for 30 min was regarded as 100%. The residual activity was indicated as percentage of activity of untreated enzyme.
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