TABLE 2.
Relative Specificity for Zn2+ and Fe2+ for WT and mutant hZIP4 transporters
A final concentration of 5 μm of indicated metal was applied to oocytes expressing WT or mutant hZIP4 protein. Data originated from 8–11 oocytes, values are means ± S.E. Zn2+/Fe2+ uptake values for mutant proteins statistically different (p > 0.05) from WT hZIP4 are in bold. Similar results were obtained upon application of 10 μm of indicated metal. ND = none detected.
| Zn2+ uptake | Fe2+ uptake | Zn2+/Fe2+ uptake | |
|---|---|---|---|
| pmol/oocyte/h | pmol/oocyte/h | ||
| WT | 2.2 ± 0.2 | 0.61 ± 0.07 | 3.6 ± 0.7 |
| H379A | 1.3 ± 0.3 | 0.64 ± 0.04 | 2.0 ± 0.6 |
| H507A | 2.7 ± 0.3 | 0.38 ± 0.07 | 7 ± 2 |
| H536A | 1.4 ± 0.2 | 2.1 ± 0.1 | 0.7 ± 0.1 |
| H540A | 3.5 ± 0.5 | 0.65 ± 0.04 | 5 ± 3 |
| H550A | 1.9 ± 0.2 | 0.46 ± 0.07 | 4.1 ± 0.8 |
| H624A | ND | 0.24 ± 0.05 | Undefined |
| H624Q | 2.4 ± 0.2 | 0.26 ± 0.06 | 9 ± 2 |