Table 1.
Apparent kinetic constants for wild-type and mutant human GCLC
| Glutamate | Cysteine | ATP | ||||
|---|---|---|---|---|---|---|
| Km (mM) | Vmax (μmol min−1 mg−1) | Km (mM) | Vmax (μmol min−1 mg−1) | Km (mM) | Vmax (μmol min−1 mg−1) | |
| Wild-type | 1.14 ± .07 | 1.00 ± .019 | 0.10 ± .02 | 1.41 ± .057 | 2.68 ± .19 | 1.43 ± .047 |
| Pro158Leu | 0.68 ± .09 | 1.18 ± .005 | 0.08 ± .01 | 1.78 ± .047 | 3.57 ± .21 | 2.13 ± .061 |
| Arg127Cys | 1.38 ± .14 | .544 ± .019 | 0.05 ± .01 | .676 ± .014 | 4.47 ± .56 | .837 ± .057 |
| His370Leua | ND | ND | ND | ND | ND | ND |
| Pro414Leua | ND | ND | ND | ND | ND | ND |
a
Steady state kinetic constants could not be determined.