TABLE 2.

Kinetic properties of representative β-lactamasesa

β-LactamaseAmbler classClavulanateSulbactamTazobactamReference(s)
KI (μM)IC50 (nM)tnKI (μM)IC50 (nM)tnKI (μM)IC50 (nM)tn
TEM-1A0.1601601.690010,0000.0197140 73, 180, 283
SHV-1A112608.612,00013,0000.071505 58, 153, 410, 411
SHV-5A201,80080 137
PC1A30180271 47, 58, 69
CTX-M-2A2002,10020 18
CcrAB>500,000>500,000>500,000400,0004,000 58
P99C>100,000>500,0005,6008.550 58
CMY-2C4,36510150116a
OXA-1D1,8004,7003801400 196, 328
OXA-2D1,4000.114010 211, 328
  • a The definition of KI may not be uniform from laboratory to laboratory. See the cited references for the methods used in each determination.