TABLE 2.

Nitrocefin hydrolysis kinetics of CHDLs^b

CDHL	kcat (s−1)	Km (μM)	kcat/Km (μM−1 s−1)	[S]a (μM)
OXA-23	177 ± 52	170 ± 45	1.04	350
OXA-24/40	27.0 ± 15.1	29.1 ± 7.7	0.93	100
OXA-58	50.9 ± 25.7	30.2 ± 5.6	1.68	100
OXA-143	20.3 ± 4.9	41.4 ± 15.4	0.49	150
OXA-235	130 ± 73	59.9 ± 11.6	2.17	150
OXA-51	123 ± 8	248 ± 44	0.50	350

^aConcentration of nitrocefin, which was used as a reporter substrate.

^bData represent the means from three independent experiments.