Table 1. Kinetic Parameters and their Corresponding Primary KIEs for the Epimerization of CDP-Glc at Distinct Temperatures^a.

T (°C)	substrate	kcat (min–1)	KM (mM)	Dkcat	Dkcat/KM
20	CDP-Glc	(1.20 ± 0.06) × 10–2	0.24 ± 0.05	2.20 ± 0.75	2.06 ± 0.67
	CDP-[2-2H]Glc	(0.62 ± 0.02) × 10–2	0.25 ± 0.03
60	CDP-Glc	0.88 ± 0.03	0.30 ± 0.04	4.30 ± 0.30	3.80 ± 0.40
	CDP-[2-2H]Glc	0.21 ± 0.01	0.26 ± 0.03
80	CDP-Glc	1.31 ± 0.04	0.16 ± 0.03	3.34 ± 0.09	3.19 ± 0.24
	CDP-[2-2H]Glc	0.40 ± 0.02	0.15 ± 0.04

^aThe k_cat and K_M values were determined by a non-linear fit to the specific rates (V/[E], min^–1) dependent on the substrate concentration. Data for the protio and deuterio substrate were fitted separately. The KIEs on k_cat (^Dk_cat) and on k_cat/K_M (^Dk_cat/K_M) were obtained by a global nonlinear fit to the data for both isotopologue substrates. The procedures used are described under Materials and Methods.