TABLE 2.

Effect of ionic strength and chloride ion on kinetic parameters for formation of cysteine synthase

Data were obtained at pH 7. ND means not defined, and IS means ionic strength.

	0.017 m IS	0.117 m IS	0.517 m IS	0.5 m Cl−a
k3 (s−1)	99 ± 13b	35 ± 3b	ND	ND
Kd (μm)	4 ± 1b	2.8 ± 0.7b	ND	ND
k3/Kd (m−1 s−1)c	25 ± 7b	12 ± 3b	(2.1 ± 0.2)b	(0.75 ± 0.02)b
	13 ± 1d	12.0 ± 0.1d	2.3 ± 0.1d	0.65 ± 0.08d

^a Ionic strength was 0.517 m.

^b Parameters were obtained with OASS varied and SAT fixed. Values in parentheses were calculated from the slope of the dependence of k_obs on [OASS].

^c Values were multiplied by 10⁻⁶.

^d Parameters were obtained with SAT varied and OASS fixed. Values were calculated from the slope of the dependence of k_obs on [SAT].