Table 1.
Kinetics of IDH isoforms as compared to homodimeric mutant enzymes with clinically relevant mutations. Unless specified “reductive”, forward reactions were measured. “n.d.”: not determined.
| Enzyme | Organism/tissue | Mutation | conditions | Km isocitrate (μM) | Kl, 2-oxo-glutarate (μM) | Km NADP+ (μM) | V max (μmol·min−1·mg−1) | Reference |
|---|---|---|---|---|---|---|---|---|
| IDH1 | Human | wt | 65 | 1900 | 49 | 44000 s−1 | [96] | |
| Human | R132H | 370 | 24 | 84 | 38 s−1 | [96] | ||
| Human | R132H | Reductive | 2OG: 965 | n.d | NADPH: 0.44 | 1000 s−1 | [96] | |
| Human | wt | 6.4 | n.d. | n.d. | 14 | [101] | ||
| Human | R132H | 1280 | n.d. | n.d. | 0.8 | [101] | ||
| Rat liver | wt | 120 | n.d. | 150 | 70 | [102] | ||
|
| ||||||||
| IDH2 | Porcine | wt | 8.4 | n.d. | 5.6 | 43 | [103] | |
| Porcine | wt | 6 | n.d. | 5 | 40 | [51] | ||
| Porcine | R133Q | 990 | n.d. | 11 | 21 | [51] | ||
| Rat liver | wt | 70 | n.d. | 60 | 66 | [102] | ||
| Rat heart | wt | 45 | 80 | 46 | 16 | [104] | ||
| Rat heart | wt | Ischemic | 17 | 250 | 46 | 38 | [104] | |
|
| ||||||||
| IDH3 | Human | wt | No ADP | 2000 | n.d. | NAD+: 60 | 26 | [105] |
| Human | wt | +1 mM ADP | 50 | n.d. | n.d. | n.d. | [105] | |