Table 2.
Kinetic characteristics of the reaction of CGL acting on various amino acids. The data for this study was obtained as described in Fig. 5 for the compounds indicated below
| Reactions | Km (mM) | Vmax (nmol min−1 mg−1) | Kcat (s−1) | Kcat/Km (M−1 s−1) |
|---|---|---|---|---|
| Cystine → cysteine persulfide + pyruvate + NH4+ | 0.22 ± 0.00 (3)§ | 0.66 ± 0.01 (3) | 1.33 | 6093 |
| Cystathionine → cysteine + 2-oxobutanoate + NH4+ | 2.28 ± 0.07 (3) | 6.78 ± 0.41 (3) | 13.7 | 6008 |
| Homoserine → 2-oxobutanoate + NH4+ | 12.4 ± 0.23 (3) | 11.6 ± 0.55 (3) | 23.4 | 1897 |
| Homocysteine-cysteine → homocysteine persulfide + pyruvate + NH4+ | 82.0 ± 3.14 (3) | 1.73 ± 0.94 (3) | 3.49 | 42.6 |
| Homocystine → homocysteine persulfide + 2-oxobutanoate + NH4+ | 60.7 ± 1.48 (3) | 0.45 ± 0.64 (3) | 0.92 | 15.1 |
§Mean ± SE (n)