Table 3.

Kinetic parameters of the purified β-lactamase CME-2

Drugkcat(s−1)Km(μM)kcat/Km(μM−1 · s−1)
Cephaloridine30.623.41.31
Benzylpenicilllin12.37.41.66
Amoxicillin6.726.50.26
Ticarcillin1.85.80.31
Piperacillin0.3<1a
Cephalothin60.641.51.46
Cefoxitin<0.01
Cefuroxime57.381.60.70
Cefoperazone2.63.80.68
Cefotaxime12.120.80.58
Ceftazidime23.61250.19
Aztreonam3.210.50.31
Imipenem<0.01
  • a —, not detectable.