TABLE 4.

β-Lactamase hydrolysis parametersa

EnzymeCephaloridinePenicillinCefotaximeCeftazidimeCefpodoximeAztreonamCefepime
Rel Vmaxkcat (s−1)Km (μM)kcat/Km (μM−1 s−1)Rel Vmaxkcat (s−1)Km (μM)kcat/Km (μM−1 s−1)Rel Vmaxkcat (s−1)Km (μM)kcat/Km (μM−1 s−1)Rel Vmaxkcat (s−1)Km (μM)kcat/Km (μM−1 s−1)Rel Vmaxkcat (s−1)Km (μM)kcat/Km (μM−1 s−1)Rel Vmaxkcat (s−1)Km (μM)kcat/Km (μM−1 s−1)Rel Vmaxkcat (s−1)Km (μM)kcat/Km (μM−1 s−1)
TEM-1100960b 700b1.471c560d14400.07c0.67dNHND0.01c0.096dNHND<0.02<0.19dNHND<0.14<1.3dNHND<0.13<1.2dNHND
TEM-310091 9.69.587791.942140130265.013121000.128274541.4<0.66<0.60NHND77701900.37
TEM-6100eND 42eND360eND6.9eND5eND18eND200eND240eND14ND63ND31eND35eND16ND68ND
TEM-10100e31 62eND170e53d5.8eND9.3e2.9d46eND200e62d150eND309.3d49ND32e10d28eND421382ND
TEM-12100fND 100fND175fND20fND4.2fND94fND6.7fND130fND19ND510ND11fND870fND40ND130ND
TEM-2610032 610.529229122.46.31.7130.13190601800.333311830.133612370.3285271050.26
TEM-28100eND 34eND300eND5.8eND3.3eND31eND76eND170eND13ND110ND17eND24eND13ND140ND
TEM-43100g170g 120g1.4140g240g26g9.24.1g6.9g33g0.2125g43g160g0.272034d990.3425g42g57g0.741729d690.42
SHV-5100150 121350751.55016245.04.869.09.20.987.211150.73<0.48<0.72NHND50751000.75
SHV-1810087 146.254473.91215138.71.54.43.7470.0796.65.75.11.10.460.4250.0161614810.17
CTX-M-10100150 1201.32843104.31523400.580.010.02NHND6.110400.250.250.38NHND6.1101100.091
FOX-5h1007901,3000.611.4119.21.2<0.01<0.08NHND<0.01<0.08NHND0.191.52.30.65<0.01<0.08NHND0.080.6860.007
K-1100430 1004.32301,00051204.3192400.079<0.01<0.01NHND3.7162800.057291234500.276.6294700.062
ACT-1100i1,200 380i3.27.1i85d10i8.50.006i0.072d7i0.0100.010.12d130.00920.11.2d130.092<0.1i<1.2dNHND<0.01<0.12dNHND
  • a Abbreviations: Rel Vmax, Vmax compared to the Vmax of cephaloridine (set at 100%); NH, hydrolysis too slow to measure Km accurately; ND, not determined.

  • b Reference 31.

  • c Reference 8.

  • d kcat calculated from relative rate and cephaloridine kcat value.

  • e Reference 3.

  • f Reference 2a.

  • g Reference 33.

  • h Reference 24.

  • i Reference 4.