TABLE 2.
Substrate profile of AmpC-type β-lactamase of strain CF01Ent1
| Substrate | Relative Vmaxa (%) | Km or Kib (μM) | Relative Vmax/Kmc (%) |
|---|---|---|---|
| Benzylpenicillin | 100 | 4.5 | 100 |
| Amoxicillin | 5 | 12 | 2 |
| Ticarcillin | <1 | 0.5 | |
| Cephalothin | 130 | 6 | 100 |
| Cefazolin | 770 | 80 | 45 |
| Cefuroxime | <1 | 0.05 | |
| Cefoxitin | <1 | 0.7 | |
| Cefotaxime | <1 | 0.2 | |
| Ceftazidime | <1 | 20 |
a
Vmax values are given as percentages of benzylpenicillin taken as 100%.
b
Ki values were determined by substrate competition with cephalothin.
c
Vmax/Km values are given as percentages of the relative Vmax/Km ratio for benzylpenicillin, which was defined as 100%.