. Author manuscript; available in PMC: 2013 Oct 9.

Published in final edited form as: Biochemistry. 2012 Sep 25;51(40):7940–7952. doi: 10.1021/bi300893v

Table 2.

Kinetic analysis of the mechanism of V51D GCL by stopped-flow CD under different experimental conditions.

Expt^a)	Conditions T° C, pH [glyoxylate]	Glycolyl-ThDP formation k₁ (s⁻¹)	Glycolyl-ThDP decarboxylation k₂ (s⁻¹)	TSA-ThDP complex k₃ (s⁻¹)	TSA release k₄ (s⁻¹)
1	6 °C, pH 7.6 1 mM	6.2 ± 0.6 ^b) 0.58 ± 0.03	n.d. ^c)	n.d.	n.d.
2	15°C, pH 7.6 1 mM	n.d.	35 ± 4	2.9 ± 0.6 ^b) 0.56 ± 0.09	n.d.
3	6°C, pH 7.6 8 mM	n.d.	n.d.	3.2 ± 1.1 ^b) 0.34 ± 0.13	0.16 ± 0.12
4	6 °C, pH 6.5 ^d) 1 mM	n.d.	n.d.	3.4 ± 0.4 ^b) 0.55 ± 0.04	0.04 ± 0.01

^a)

Experiments are numbered according to the text in Results. The experimental data are presented in Figures 6 A-D.

^b)

The experimental curves were treated as a double exponential leading to two rate constants fast and slow.

^c)

n.d., not detected.

^d)

Experiment was conducted at pH 6.5, favorable for V51D GCL as demonstrated in this publication.