Table 2.

Kinetic parameters of purified β-lactamase RAHN-1a

Substratekcat(s−1)Km(μM)kcat/Km (mM s−1)
Benzylpenicillin210240
Amoxicillin0.51540
Ticarcillin0.2540
Piperacillin110100
Cephalothin1170160
Cephaloridine613045
Cefuroxime110100
Cefoxitin<0.01NDbND
Cefotaxime0.51050
Ceftazidime<0.01ND ND
Ceftriaxone0.55120
Cefpirome765010
Cefepime514005
Aztreonam0.53401
Imipenem<0.01ND ND
  • a Standard deviations of the kinetic parameters were within 15%.

  • b ND, not determined.