In vitro N-reduction of N-hydroxy-melagatran to melagatran by liver and kidney microsomes and mitochondria of different species and kinetic data
| Km | Vmax | Vmax/Km | |
|---|---|---|---|
| mM | nmol/min/mg protein | l/min/mg protein | |
| Pig liver microsomes | 0.69 ± 0.04 2-a | 5.60 ± 0.08 | 8.12 × 10−6 |
| Human liver microsomes | 1.59 ± 0.04 | 2.26 ± 0.00 | 1.42 × 10−6 |
| Pig liver mitochondria | 0.30 ± 0.02 | 15.06 ± 0.67 | 5.02 × 10−5 |
| Human liver mitochondria | 0.98 ± 0.05 | 8.68 ± 0.15 | 8.86 × 10−6 |
| Pig kidney microsomes | 0.78 ± 0.06 | 13.83 ± 0.17 | 1.77 × 10−5 |
| Human kidney microsomes | 1.08 ± 0.14 | 3.93 ± 0.18 | 3.64 × 10−6 |
| Pig kidney mitochondria | 0.47 ± 0.03 | 20.67 ± 0.41 | 4.42 × 10−5 |
| Human kidney mitochondria | 1.40 ± 0.11 | 3.47 ± 0.07 | 2.48 × 10−6 |
Incubation mixtures have been optimized for protein content, NADH concentration, and substrate concentration. An incubation mixture consisted of 0.15 mg/ml microsomal or mitochondrial protein of pig or human liver or 0.05 mg/ml of pig kidney or 0.2 mg/ml of human kidney preparations, 2 mM N-hydroxy-melagatran as substrate, and 1 mM NADH as cosubstrate in 100 mM potassium phosphate buffer pH 6.3. For incubation conditions and HPLC analysis, see Materials and Methods.
↵2-a Conversion rates are means ± S.D. of four determinations.