Table 1. Affinity constants of AtENT1, 3, 4, 6 and 7 for purine and pyrimidine nucleosides.
Km values were obtained by incubating yeast cells, expressing the respective proteins in 3H-labelled nucleosides for 2 min. The affinity constants were calculated according to Hanes plot. Results are means±S.E.M. for three independent experiments. n.d., not determined.
| Km (μM) | ||||
|---|---|---|---|---|
| Transporter | Adenosine | Guanosine | Cytidine | Uridine |
| AtENT1 | 3.6* | IC50 28.0* | IC50 20.0* | n.d. |
| AtENT3 | 15.5 | 18.0 | 10.8 | 9.5 |
| AtENT4 | 49.1 | 7.3 | 94.2 | 27.8 |
| AtENT6 | 3.0 | 11.5 | 21.2 | 6.4 |
| AtENT7 | 9.8 | 9.4 | 40.0 | 13.4 |
* Data taken from Möhlmann et al. [9].