Table 2.
Kinetic data for the pure IMP-28 and IMP-1 β-lactamasesa
| Antibiotic |
kcat (s−1) |
Km (μM) |
kcat/Km (μM−1 s−1) |
|||
|---|---|---|---|---|---|---|
| IMP-1 | IMP-28 | IMP-1 | IMP-28 | IMP-1 | IMP-28 | |
| Nitrocefin | 63 ± 10 | 35.86 ± 12 | 27 ± 3 | 17.6 ± 4 | 2.3 | 2.03 |
| Ampicillin | 950 ± 50 | 0.649 ± 0.14 | 200 ± 25 | 359 ± 172 | 4.8 | 1.8 10−3 |
| Cefoxitin | 16 ± 1 | 0.75 ± 0.07 | 8 ± 1 | 7 ± 0.3 | 2 | 0.1 |
| Cefotaxime | 1.3 ± 5 | 0.98 ± 0.042 | 4 ± 0.5 | 9.4 ± 0.5 | 0.35 | 0.104 |
| Ceftazidime | 8 ± 1 | 0.35 ± 0.046 | 44 ± 3 | 112 ± 10 | 0.18 | 3 10−3 |
| Cefepime | 7 ± 0.5 | 0.145 ± 0.01 | 11 ± 1 | 72 ± 9 | 0.66 | 2 10−3 |
| Imipenem | 46 ± 3 | 8.66 ± 0.17 | 39 ± 4 | 90 ± 21 | 1.2 | 0.096 |
| Meropenem | 50 ± 5 | 3.05 ± 0.1 | 10 ± 2 | 14.4 ± 0.4 | 5 | 0.21 |
a
Data are means ± standard deviations (where applicable) and are from Laraki et al. (8).