Table 5.
ΔΨ formation in inverted vesicles and wild-type and mutant enzymes reconstituted in proteoliposomes.
| Na+ stimulation | ||||
|---|---|---|---|---|
| Subunit | Mutant | Purified Enzyme | Reconstituted Enzyme | ΔΨ (mV) |
| WT | 7.74 | 9.6 | −165 | |
| B | ||||
| E28A | 1.87 | 2.6 | −35 | |
| E144L | 2.48 | 3.5 | −65 | |
| D224A | 3.87 | −90 | ||
| E274A | 4.50 | |||
| D346A | 1.30 | 1.12 | UD | |
| E380A | 3.92 | |||
| D397A | 0.90 | 1.1 | UD | |
| D | ||||
| D17A | 5.22 | |||
| E40L | 4.05 | |||
| D88L | 1.87 | 2.3 | −25 | |
| E119A | 5.76 | |||
| D133A | 1.67 | 1.8 | −10 | |
| E153A | 4.46 | |||
| E | ||||
| E15A | 4.96 | |||
| E95A | 1.30 | 1.6 | UD | |
| E138A | 5.96 | |||
| E162G | 4.64 | |||
ΔΨ formation was measured in preparations of purified enzyme reconstituted into proteoliposomes, using Oxonol IV, as indicated in the Materials and Methods section. The spectrophotometric signal of Oxonol IV was calibrated by changing the diffusion potential of potassium. UD, undetectable (<−5mV).