TABLE 3.
Steady-state kinetic results for tVIM-7, tVIM-7-F218Y, and tVIM-7-H224Y
| Compound | tVIM-7 |
tVIM-7-F218Y |
tVIM-7-H224Y |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Km (μM) | kcat (s−1) | kcat/Km (s−1 · μM−1) | Km (μM) | kcat (s−1) | kcat/Km (s−1 · μM−1) | Km (μM) | kcat (s−1) | kcat/Km (s−1 · μM−1) | |
| Penicillins | |||||||||
| Benzylpenicillina | 23 ± 3 | 59 ± 7 | 2.5 | 2.2 ± 0.6 | 198 ± 14 | 89 | 29.8 ± 3.0 | 144 ± 12 | 4.83 |
| Ampicillina | 23.3 ± 1.7 | 17.6 ± 1.1 | 0.76 | 0.78 ± 0.26 | 17 ± 5 | 20 | 37 ± 11 | 170 ± 4 | 4.63 |
| Cephalosporins | |||||||||
| Cefepime | 179 ± 14 | 0.450 ± 0.023 | 0.0025 | 79 ± 9 | 1.66 ± 0.08 | 0.02 | 108 ± 20 | 4.4 ± 0.3 | 0.041 |
| Ceftazidime | 61 ± 19 | 0.120 ± 0.007 | 0.0020 | 62 ± 20 | 1.4 ± 0.3 | 0.02 | 30 ± 6 | 0.39 ± 0.02 | 0.013 |
| Cefoxitin | 20 ± 4 | 0.64 ± 0.03 | 0.032 | 12.7 ± 0.8 | 3.50 ± 0.08 | 0.278 | 15.5 ± 2.0 | 3.9 ± 0.1 | 0.25 |
| Cefuroxime | 12.9 ± 2.5 | 4.57 ± 0.05 | 0.35 | 6.3 ± 0.6 | 22.5 ± 0.5 | 3.6 | 13.7 ± 2.1 | 5.5 ± 0.2 | 0.40 |
| Carbapenems | |||||||||
| Ertapenem | 18.9 ± 2.2 | 12.810 ± 0.013 | 0.68 | 6.4 ± 0.3 | 6.06 ± 0.07 | 0.95 | 14.0 ± 1.1 | 8.95 ± 0.13 | 0.64 |
| Imipenem | 29 ± 10 | 7.71 ± 0.17 | 0.27 | 9.3 ± 0.6 | 24.7 ± 0.3 | 2.7 | 27.8 ± 2.4 | 50.0 ± 0.9 | 1.80 |
| Meropenem | 20.0 ± 1.6 | 25.580 ± 0.026 | 1.28 | 15.9 ± 0.6 | 11.7 ± 0.1 | 0.74 | 25.3 ± 2.7 | 23.9 ± 0.5 | 0.94 |
a
The Km values were measured as inhibition constants (Ki) in a competitive model using nitrocefin as the reporter substrate.