Table 1.
Kinetic Properties of Wild-Type and Mutant Forms of IDH
| isocitratea |
NAD+b |
||||
|---|---|---|---|---|---|
| enzyme | Vmax (U/mg) (−AMP/+AMP) | S0.5 (mM) (−AMP/+AMP) | Hill coef. (−AMP/+ AMP) | Vmax(U/mg) | S0.5 (mM) |
| wild-type | 30.5/31.8 (±1.0/1.6) | 0.57/0.10 (±0.04/0.01) | 3.6/3.5 (±0.1/0.3) | 35.0 | 0.12 |
| C56S/C242S | 29.8/31.7 (±1.5/2.1) | 1.11/0.16 (±0.02/0.04) | 3.6/3.1 (±0.1/0) | 30.7 | 0.08 |
| C150S | 38.7/40.3 (±1.4/2.5) | 0.85/0.19 (±0.01/0.02) | 2.5/2.5 (±0.4/0.3) | 39.9 | 0.10 |
a
Kinetic properties were determined as described under Experimental Procedures. Properties with respect to isocitrate were determined in the absence or presence of 100μM AMP, and values represent three independent measurements (±standard deviations).
b
Values for kinetic properties with respect to NAD+ represent averages of two independent measurements.