TABLE 2.
Kinetic parameters of CMY-2, CMY-172, and CMY-178
| Moleculea | Datab by variant |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CMY-2 |
CMY-172 |
CMY-178 |
||||||||||
| Km (μM) | Kcat (s−1) | Kcat/Km (μM−1 s−1) | Ki (μM) | Km (μM) | Kcat (s−1) | Kcat/Km (μM−1 s−1) | Ki (μM) | Km (μM) | Kcat (s−1) | Kcat/Km (μM−1 s−1) | Ki (μM) | |
| NCF | 59.88 ± 2.59 | 732.18 ± 16.07 | 12.25 ± 0.60 | 12.02 ± 0.66 | 52.41 ± 2.65 | 4.36 ± 0.05 | 12.50 ± 0.31 | 55.81 ± 1.04 | 4.46 ± 0.08 | |||
| CAZ | NMc | (32.10 ± 2.10) × 10−3 | NM | (1.06 ± 0.00) × 10−3 | NM | (9.27 ± 0.29) × 10−3 | ||||||
| TAZ | 0.76 ± 0.07 | 2.12 ± 0.34 | 2.49 ± 0.51 | |||||||||
a
NCF, nitrocefin; CAZ, ceftazidime; TAZ, tazobactam.
b
Km, kcat, and Ki values are shown as the means ± standard deviation from three independent experiments.
c
NM, not measurable due to a low initial rate of hydrolysis.