TABLE 3.

Kinetic properties of some subclass B3 metallo-β-lactamases with relevant β-lactam compounds^a

Substrate	BJP-1		L1		FEZ-1		GOB-1
	Km (μM)	kcat/Km (M−1·s−1)	Km (μM)	kcat/Km (M−1·s−1)	Km (μM)	kcat/Km (M−1·s−1)	Km (μM)	kcat/Km (M−1·s−1)
Ampicillin	670	1.9 × 104	40	4.4 × 106	>5,000d	1.1 × 104	—e	—
Piperacillin	700	6.7 × 104	20	7.0 × 106	4,200	1.2 × 104	170	1.7 × 106
Ticarcillin	NDb	NHc	140	2.7 × 106	>5,000d	1.3 × 104	150	5.2 × 105
Cephalothin	230	5.8 × 105	8.9	9.2 × 106	120	2.5 × 106	24	6.7 × 105
Ceftazidime	>700d	4.3 × 103	145	2.0 × 105	>1,000d	4.0 × 103	71	7.6 × 105
Imipenem	260	6.0 × 104	90	7.3 × 105	>1,000d	2.0 × 105	60	6.6 × 105
Meropenem	190	8.3 × 105	10	4.5 × 106	85	5.0 × 105	5	5.3 × 106

^aData for the various enzymes are from the following references: BJP-1, 49; L1, 8, 20, and 45; FEZ-1, 35; GOB-1, 5.

^bND, not determined.

^cNH, no hydrolysis detected.

^dFirst-order kinetics were observed with the substrate.

^e—, data not available.