TABLE 1.
Functional properties of TacDAT compared with DAT
All values are means (S.E. interval) for the K values and mean ± S.E. for Vmax and Bmax derived from three independent experiments performed in HEK293 cells. The Km and Kd values were calculated from the pIC50 values determined by non-linear regression analysis of [3H]dopamine uptake and [3H]CFT binding data as described previously (12, 26). The S.E. intervals were calculated from pK ± S.E. The Ki values were calculated from IC50 values determined by non-linear regression analysis of uptake data and using the equation Ki = IC50/(1+ (L + Km)) where L is the concentration of [3H]dopamine. The S.E. interval was calculated from pK ± S.E. All data calculations were done using Prism 5.0 from GraphPad Software, San Diego, CA.
| DAT | TacDAT | |
|---|---|---|
| [3H]Dopamine Km (μm) | 0.92 (0.62–1.4) | 0.40 (0.36–0.47) |
| [3H]Dopamine Vmax (fmol/min/105) | 2486 ± 236 | 511 ± 104 |
| Cocaine Ki (nm) | 154 (128–187) | 86.4 (66.6–112) |
| Nomifensine Ki (nm) | 75.1 (49.3–114) | 45.7 (31.9–65.4) |
| [3H]CFT Kd (nm) | 18.8 (15.3–23.0) | 8.32 (7.80–8.87) |
| [3H]CFT Bmax (nm) | 217 ± 33 | 69.0 ± 8.0 |