TABLE 3.
Catalytic activity of CjMan26C mutants
| CjMan26C varianta | kcat/Kmb | Activity relative to CjMan26Cc | Activity relative to CjMan26A |
|---|---|---|---|
| min−1M−1 | |||
| Wild type CjMan26C | 3.0 × 109 ± 3.3 × 108 | 1.0 | 2.1 × 102 |
| Wild type CjMan26A | 1.4 × 107 ± 2.8 × 105 | 4.6 × 10−3 | 1.0 |
| E221A | 7.5 × 102 ± 2.6 × 101 | 2.5 × 10−7 | 5.4 × 10−4 |
| E338A | 7.7 × 102 ± 1.3 × 101 | 2.6 × 10−7 | 5.5 × 10−4 |
| L129G | 4.0 × 106 ± 3.8 × 105 | 1.3 × 10−3 | 0.29 |
| L129A | 7.4 × 106 ± 1.5 × 105 | 2.5 × 10−3 | 0.53 |
| D130Gd | 2.7 × 105 ± 7.5 × 104 | 9.0 × 10−5 | 1.9 × 10−2 |
| D130Ad | 2.9 × 104 ± 3.1 × 103 | 9.7 × 10−6 | 2.1 × 10−3 |
| L129G/D130G | 8.2 × 107 ± 9.1 × 106 | 2.4 × 10−2 | 5.9 |
| L129A/D130Ad | 4.5 × 104 ± 4.5 × 103 | 1.5 × 10−5 | 3.2 × 10−3 |
| ΔL129/D130d | 2.7 × 105 ± 1.6 × 104 | 9.0 × 10−5 | 1.9 × 10−2 |
| ΔN128/L129/D130d | 2.7 × 104 ± 1.7 × 103 | 9.0 × 10−6 | 1.9 × 10−3 |
| ΔN128/L129/D130/A131d | 3.4 × 104 ± 6.6 × 102 | 1.1 × 10−5 | 2.4 × 10−3 |
a
The varants are all of CjMan26C.
b
The substrate used to measure catalytic efficiency was mannotetraose.
c
The activity is expressed as decrease in activity relative to wild type CjMan26C. For example, wild type CjMan26A is 210-fold less active than wild type CjMan26C.
d
Variants that display endo-activity (see Table 4).