Table 3. Relative anion permeabilities of WT EAAT1 and R477H.
| pH | Transporter | Erev | PX−/PCl− | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Cl− | Br− | I− | NO3− | PBr−/PCl− | PI−/PCl− | PNO3−/PCl− | |||
| mV | mV | mV | mV | ||||||
| pH 5.5 | EAAT1 | 51 ± 4 | 28 ± 3 | −4 ± 3 | −10 ± 3 | 2.5 ± 0.1 | 9.0 ± 0.5 | 11.1 ± 0.6 | |
| R477H | 14 ± 2 | 0 ± 1 | −29 ± 1 | −25 ± 2 | 1.75 ± 0.07 | 5.8 ± 0.4 | 5.1 ± 0.5 | ||
| pH 8.5 | EAAT1 | 50 ± 2 | 46 ± 2 | 17 ± 2 | 13 ± 2 | 1.19 ± 0.03 | 3.8 ± 0.2 | 4.4 ± 0.3 | |
| R477H | −21 ± 3 | −21 ± 3 | −24 ± 3 | −24 ± 2 | ND | ND | ND | ||
Reversal potentials (Erev) of saturating l-glutamate–elicited currents were obtained in buffers containing 10 mM Cl−, Br−, I−, and NO3− salts. Relative anion permeabilities were calculated from Erev measurements using the Goldman–Hodgkin–Katz equation (Eq. 3). ND indicates that no relative anion permeability could be measured as Cl− is not permeant through R477H at pH 8.5. Data shown represent the mean ± SEM (n ≥ 4).