Table 3.

Kinetic parameters of Toho-2 β-lactamase

Antibiotickcata (s−1)Km or apparent Ki (μM)kcat/Km (μM−1s−1)
Penicillin G3.660.6
Ampicillin1.2120.1
Oxacillin9.1910.1
Carbenicillin14180.8
Piperacillin130841.6
Cephalothin12,00047025
Cephaloridine4,50018025
Cefoxitin<0.14.8<0.1
Ceftizoxime301500.2
Ceftazidime1.3160<0.1
Cefotaxime220663.3
Aztreonam0.1140<0.1
Imipenem4.8
Clavulanic acid2.4
Sulbactam4.5
Tazobactam0.3
  • a Absolute k catvalue.