Table 1.
Vmax |
|||||||
---|---|---|---|---|---|---|---|
Kt, μM | Mutant/WT | Ki, μM | Rate: pmol·mg protein−1·min−1 | Relative expression at the cell surface (P425R/WT) | Corrected for expression | Mutant/WT–corrected for expression | |
WT | |||||||
MTX | 2.03 ± 0.54 | 3.1 ± 0.4 | 277.4 ± 22.9 | 1.0 | |||
PMX | 0.60 ± 0.08 | 102.9 ± 3.9 | |||||
P425R | |||||||
MTX | 10.1 ± 1.53 | 4.98 | 29 ± 2 | 120.4 ± 8.6 | 0.58 | 208 | 0.73 |
PMX | 0.41 ± 0.07 | 0.68 | 25.3 ± 1.2 | 44 | 0.44 |
Values are means ± SE. A comparison of methotrexate (MTX) and pemetrexed (PMX) influx kinetics (Kt and Kt) based on experiments represented in the data of Figs. 4 and 5. Relative expression was measured by ImagejJ densitometry from 2 separate experiments and used to normalize the influx Vmax values. PCFT, proton-coupled folate transporter; WT, wild type.