Table 2.

Hydrolysis parameters for SHV-1 and SHV-11 β-lactamases for selected β-lactamsc

AntibioticWavelengthΔɛ(M−1cm−1)SHV-1 J53R1010 (reference)aSHV-11 (S. dysenteriae)
Benzylpenicillin232800100100
Ampicillin235670150300
Oxacillin260400<0.196
Cloxacillin260140<0.145
Carbenicillin2358302045
Nitrocefin48215,000 NDc 150
Cephaloridine2559,0005035
Cefazolin2736,6001010
Cefuroxime2737,500<0.16
Cefotaxime2646,700<0.18
Cefacetrile2607,40054
Cefoperazone2605,700ND4
Cefaclor2607,200815
Ceftizoxime2555,000<0.118
Ceftazidime2608,600<0.1<0.1
Cefsulodin2655,800<0.1<0.1
Cefoxitin2657,380<0.1<0.1
Imipenem2979,000<0.1<0.1
  • a SHV-1 J53R1010 was a gift from Antone A. Medeiros.

  • b ND, not determined.

  • c Results are the means of three determinations (standard deviation, ≤10%). Rates of hydrolysis (V max) of β-lactams are expressed relative to the rate of hydrolysis of benzylpenicillin, which was set at 100.