Table 1. Steady-state kinetic parameters of the wild-type and mutant forms of the TEM-1 β-lactamase.

Form	kcat (s−1)	KM (M)	kcat/KM (s−1·M−1)
Ampicillin
Wild-type	1040±34	(6.5±1.9)×10−5	(1.6±0.5)×107
V216C	873±13	(1.4±0.1)×10−4	(6.3±0.1)×106
Labelled V216C	650±58	(7.0±0.8)×10−4	(9.2±1.9)×105
Penicillin G
Wild-type	746±31	(1.3±0.2)×10−4	(5.5±1.2)×106
V216C	491±13	(1.6±0.2)×10−4	(3.0±0.4)×106
Labelled V216C	148±9	(2.6±0.4)×10−4	(5.6±1.2)×105