TABLE 2.

Kinetic parameter of PJM-1 and other class B3 metallo-β-lactamases

Substrate	PJM-1			AIM-1c			kcat/Km (M−1 s−1)
	kcat (s−1)	Km (μM)	kcat/Km (M−1 s−1)	kcat (s−1)	Km (μM)	kcat/Km (M−1 s−1)	L1c	SMB-1c	THIN-Bc
Ampicillin	370 ± 3.1	51 ± 0.55b	7.2 × 106	594	41	1.4 × 106	4.4 × 106	2.4 × 106	3.7 × 105
Piperacillin	150 ± 4.4	14 ± 0.44b	1.1 × 107	337	17	2 × 107	7.0 × 106	1.8 × 105	2.0 × 105
Cephalothin	38 ± 0.36	13 ± 0.19	2.9 × 106	529	38	1.4 × 107	-	1.9 × 106	-
Cefuroxime	86 ± 1.8	120 ± 3.8	6.9 × 105	292	29	9.9 × 106	2.7 × 106	1.4 × 106	2.8 × 106
Cefoxitin	31 ± 0.50	26 ± 0.98	1.2 × 106	145	26	5.7 × 106	5.5 × 105	-	-
Cefotaxime	90 ± 1.9	130 ± 7.0	7.1 × 105	609	49	1.2 × 107	2.6 × 106	8.9 × 105	2.0 × 106
Ceftazidime	0.091 ± 0.00036	150 ± 3.7	6.2 × 102	7	148	4.9 × 104	-	7.7 × 104	1.4 × 105
Cefepime	1.0 ± 0.027	230 ± 6.1	4.3 × 103	93	594	1.6 × 105	1.9 × 104	3.6 × 103	7.9 × 103
Imipenem	66 ± 2.1	36 ± 1.4b	1.8 × 106	1,700	97	1.7 × 107	7.5 × 105	3.9 × 106	1.5 × 106
Meropenem	110 ± 3.8	34 ± 2.3	3.3 × 106	1,000	163	6.8 × 106	4.5 × 106	4.2 × 106	5.0 × 106
Ertapenem	190 ± 3.4	57 ± 1.3	3.3 × 106	-f	-	-	-	-	-
Aztreonama	NHd	>1,000b	NDe	NH	NH	ND	ND	ND	ND
Nitrocefin	79 ± 1.5	2.6 ± 0.11	3.1 × 107	-	-	-	2.9 × 106	-	-

^aThe K_i value for aztreonam exceeds the measurable range.

^bK_i value.

^cThe references values of AIM-1, L1, SMB-1, and THIN-B are 8, 3, 7, and 15, respectively.

^dNH, no hydrolysis.

^eND, not determined.

^f-, no data available.