Table 2.
Enzyme Species | Zn2+ (moles/subunit) | kcat/Km (M−1 s−1) |
---|---|---|
PR-AMP Cyclohydrolase | 1.1, 0.88, 1.07 | 4.1 ± 0.8 × 105 |
D92E | 0.72, 0.51 | 2.3 ± 0.2 × 103 |
C93A | 0.003, 0.020 | Inactive |
D94A | 0.60, 0.43 | Inactive |
D94E | 0.65, 0.63 | 1.8 ± 0.2 × 102 |
C109A | 0.37, 0.22 | Inactive |
H110A | 1.16, 1.09 | 8.3 ± 2 × 102 |
C116A | 0.99, 0.90 | Inactive |
C109/116A | 0.027, 0.007 | Inactive |
DTNB or MMTS* | 0.27, or 0.19*, 0.52* |
The average percent deviation for the independent Zn2+ measurements is 10%.