TABLE 4.
Kinetic parameters of the purified β-lactamase VIM-2
| Antimicrobial agent | kcat (s−1) | Km (μM) | kcat/Km (μM−1 · s−1) |
|---|---|---|---|
| Benzylpenicillin | 55.8 | 49 | 1.14 |
| Amoxicillin | 29.7 | 54 | 0.55 |
| Ticarcillin | 31.7 | 46 | 0.69 |
| Piperacillin | 32.7 | 72 | 0.45 |
| Cephalothin | 56.2 | 44 | 1.28 |
| Cefoxitin | 2.8 | 24 | 0.12 |
| Cefuroxime | 12.1 | 22 | 0.55 |
| Cefoperazone | 29.8 | 49 | 0.61 |
| Cefsulodin | 26.0 | 521 | 0.05 |
| Cefotaxime | 27.5 | 32 | 0.86 |
| Cefpirome | 9.2 | 123 | 0.07 |
| Cefepime | 4.7 | 184 | 0.03 |
| Ceftazidime | 88.7 | 98 | 0.90 |
| Aztreonam | <0.5 | NDa | —b |
| Moxalactam | 14.8 | 80 | 0.18 |
| Meropenem | 1.4 | 5 | 0.28 |
| Imipenem | 9.9 | 10 | 0.99 |
a
ND, not determinable.
b
—, in this case, the hydrolysis parameters could not be calculated.