Table 1.

Kinetic properties of wild-type CSE (WT) and the indicated mutants using β-CA as substrate. CSEs β-lyase reactions were determined by coupling a color enzymatic reaction with pyruvate oxidase and peroxidase, as described in the Materials and Methods section. Values represent the mean ± S.E. for three independent experiments. Km and Vmax values were determined from double-reciprocal plots (Lineweaver-Burk) of data obtained from experiments performed with four concentrations (1–30 mM) of β-CA.

CSE	WT	C136V	C171V	C136V/C171V
Km (mM)	7.57 ± 2.23	11.77 ± 2.58	6.13 ± 0.43	8.40 ± 0.64
Vmax (µmol/min/mg CSE)	29.93 ± 12.06	28.30 ± 6.67	22.00 ± 4.39	29.12 ± 3.52
Vmax/Km	3.95	2.40	3.58	3.46