Table 3. Kinetic constants for the hydrolysis of ampicillin^a.

Protein	Km (µM)		k cat (S-1)		k cat/Km ratioc
	− Maltose	+ Maltose	− Maltose	+ Maltose
Ph8	730±120	700±100	1870±220	1950±110	1.1±0.3
c4	73±4	77±8	2280±120	2350±110	1.0±0.1
BLAb	32	−	1050	−	−

^aAssays were at 37°C in 10 mM phosphate buffer (pH 7.0) with or without 5 mM maltose.

^bAt 30°C in 50 mM phosphate buffer (pH 7.0) [9]. Previous studies have shown that BLA enzyme activity is unaffected by maltose [4].

^c(k _cat/K_m)_+maltose/(k _cat/K_m)_−maltose.