TABLE 1.

Steady-state kinetic constants of recombinantly expressed and native human TKT

Assay conditions are detailed under “Experimental Procedures.”

	Aspec	kcat	Km(X5P)	Km(R5P)
	units/mg	s−1	μm	μm
Recombinant human TKT-His6 (30 °C, this study)	2.7 ± 0.1	3.1 ± 0.1	303 ± 79	610 ± 36
Recombinant human TKT (30 °C, this study)	5.5 ± 0.1	6.3 ± 0.1	255 ± 37	480 ± 41
Recombinant human His6-TKT (37 °C)a	13.5	15.5	270 ± 20	510 ± 50
Native human TKT (37 °C)a	12–17	14–19	490 ± 140	530 ± 40

^a Data from Ref. 1.