Table 5.

β-Lactam Synthetase as a Carbapenam Synthetase Compared to the Wild-Type CPS and β-LS Catalytic Reactions^a

	varied substrate	kcat (s−1)	−Δ	Km (mM)	+Δ
β-LS	CEA	0.695 ± 0.007	1	0.040 ± 0.001	1
CPS	CMPr	0.304 ± 0.005	2.3	0.17 ± 0.01	4.3
β-LS	CMPr	0.026 ± 0.002	27	4.9 ± 0.7	123

^a−Δ shows a fold decrease in k_cat and ⁺Δ a fold increase in K_m,CMPr of β-LS and CPS at pH 8.3 and 8.67, respectively, relative to β-LS and its natural substrate, CEA, at pH 8.3.