Kinetic analysis of ABCC4-mediated [3H]LTB4 and [3H]LTC4 transport Rates of ATP-dependent transport of [3H]LTB4 in the presence of 5 mM GSH and of [3H]LTC4 were determined in membrane vesicles from ABCC4-transfected V79 cells and in plasma membrane fractions from human platelets under substrate concentrations described under Materials and Methods. The Km values were calculated from double-reciprocal plots. Data represent mean values ± S.D. from a triplicate determination.
Leukotriene | Km | Vmax/Km |
|---|---|---|
| μM | μl × min-1 × mg protein-1 | |
| Vesicles from V79-ABCC4 | ||
| LTB4 + 5 mM GSH | 5.2 ± 0.2 | 1.9 |
| LTC4 | 0.13 ± 0.02 | 287.7 |
| Vesicles from platelets | ||
| LTB4 + 5 mM GSH | 5.6 ± 0.6 | 0.3 |
| LTC4 | 0.32 ± 0.03 | 30.3 |