TABLE 2.
Kinetic parameters for the β-lactamase purified from P. penneri R15 and P. vulgaris Ro104
| Antimicrobial agent |
P. penneri
|
P. vulgarisa
|
|||||
|---|---|---|---|---|---|---|---|
| kcatb (s−1) | Kmb (μM) | kcat/Km (s−1 mM−1) | kcatb (s−1) | Kmb (μM) | kcat/Km (s−1 mM−1) | ||
| Benzylpenicillin | 10 | 6.0 | 1,700 | 19 | 4.0 | 4,875 | |
| Amoxicillin | 10 | 14.7 | 700 | 20 | 12.3 | 1,626 | |
| Ticarcillinc | 0.5 | 5.0 | 100 | 1.1 | 4.6 | 239 | |
| Cephalothin | 260 | 28 | 9,300 | 695 | 26 | 26,700 | |
| Cephaloridine | 210 | 83 | 2,500 | 496 | 92 | 6,500 | |
| Cefuroxime | 165 | 190 | 860 | 195 | 40 | 4,900 | |
| Cefamandole | 376 | 320 | 1,175 | 4,480 | 190 | 23,600 | |
| Cefotaxime | 60 | 950 | 63 | 75 | 170 | 447 | |
| Ceftriaxone | 65 | 500 | 130 | 79 | 45 | 1,800 | |
| Ceftazidimec | 0.5 | 350 | 1.4 | 1.0 | 170 | 6.0 | |
| Cefoxitinc | 5 | 2.3 | |||||
| Moxalactamc | 10 | 5.1 | |||||
| Imipenemc | 6 | NDd | ND | ND | |||
a
Data were taken from Peduzzi et al. (19).
b
For kcat values standard deviations (SD) are lower than 10%, and for Km values, standard deviations are lower than 20%.
c
For compounds with poor (ticarcillin, ceftazidime) or undetectable (cefoxitin, moxalactam, imipenem) hydrolytic activities, Ki instead of Km values were determined by competition procedures with cephalothin as the reporter substrate.
d
ND, not determined.