Table 3.

Kinetic parameters for V. cholerae CARB-6 β-lactamase in comparison with the published values for β-lactamases TEM-1, SAR-1, and CARB-1 to CARB-3a

AntibioticKm(μM)Vm(relative)b
CARB-6SAR-1TEM-1CARB-1CARB-2CARB-3CARB-6SAR-1TEM-1CARB-1CARB-2CARB-3
Penicillin G964224137.39.8100100100100100100
Amoxicillin157 —c4313.616.421.8266846312897
Ampicillin68353020.9246311194.593100
Ticarcillin55104018.8215938812697
Carbenicillin19014122729512210126343147
Piperacillin74315.986
Mezlocillin58.524615.514201001008683111
Oxacillin376583124.55.2555.411.412.5
Cephaloridine5269395040.520841859.5217614.61644.2
Cephalothin<0.5201.250.80.5
  • a Data for TEM-1 (21), SAR-1 (29), and CARB-1 to CARB-3 (16, 18) have been published previously.

  • b Vm is expressed as a percentage of hydrolysis of benzylpenicillin (for which the Vm is equal to 100), which was used as a reference.

  • c —, not determined.