TABLE 4.

Effect of pH on kinetic parameters for formation of cysteine synthase

Ionic strength was 0.017, 0.069, and 0.026 m at pH 7, 8, and 9, respectively.

	pH 7	pH 8	pH 9
k3 (s−1)	99 ± 13a	91 ± 15a	55 ± 10a
Kd (μm)	4 ± 1a	5 ± 1a	13 ± 3a
k3/Kd (m−1 s−1)b	25 ± 7a	18 ± 5a	4 ± 1a
	13 ± 1c	12.0 ± 0.2c	2.2 ± 0.1c

^a Parameters were obtained with OASS varied and SAT fixed.

^b Values were multiplied by 10⁻⁶.

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