. Author manuscript; available in PMC: 2014 May 22.

Published in final edited form as: J Am Chem Soc. 2013 May 10;135(20):7583–7592. doi: 10.1021/ja400761x

Table 2.

Michaelis constants and dissociation constants of dUMP and CH₂H₄fol for ecTSase, in the absence (w/o) and presence (w/) of 50 mM MgCl₂ at 25 °C.

	$K_{M}^{dUMP}$ ^a (μM)	$K_{d}^{dUMP}$ ^b (μM)	$K_{M}^{{CH}_{4} H_{4} fol}$ ^a (μM)	$K_{d}^{{CH}_{4} H_{4} fol}$ ^c (μM)
w/ Mg²⁺	2.4 ± 0.2	14 ± 2	15 ± 1	8 ± 1
w/o Mg²⁺	0.5 ± 0.1	8.5 ± 0.9	17 ± 2	17 ± 2

Measured by steady-state kinetics (Figures 1 and S1).

Measured by the fluorescence assay (Figure 3B).

Calculated as describe at the Experimental Section, using Eq 5 and data from Table 3