Ordered binding of Na+ and amino acid to SA1
| Vm (mV) | Km ± SEM | I/IND6 ± SEM | |
|---|---|---|---|
| Km alanine, ND6 | −90 | 0.51 ± 0.14 | 1 |
| −50 | 0.79 ± 0.21 | 1 | |
| −30 | 1.07 ± 0.29 | 1 | |
| +10 | 2.41 ± 0.8 | 1 | |
| Km alanine, ND96 | −90 | 0.22 ± 0.03 | 1.1 ± 0.08 |
| −50 | 0.24 ± 0.03 | 1.1 ± 0.04 | |
| −30 | 0.28 ± 0.05 | 1.1 ± 0.08 | |
| +10 | 0.46 ± 0.08 | 1.3 ± 0.10 | |
| I/I0.1A | |||
| Km Na+, 0.1 mmalanine | −90 | 63.5 ± 57.3 | 1 |
| −50 | 116 ± 94.4 | 1 | |
| −30 | 128 ± 106 | 1 | |
| +10 | 52.3 ± 37.6 | 1 | |
| Km Na+, 1 mmalanine | −90 | 5.5 ± 1.4 | 1.8 ± 0.25 |
| −50 | 9.4 ± 1.8 | 1.5 ± 0.36 | |
| −30 | 13 ± 2.5 | 1.5 ± 0.38 | |
| +10 | 27.7 ± 6.7 | 2.7 ± 0.40 |
The Km for alanine was determined in individual oocytes at two concentrations of Na+ (6 and 96 mm) by replacing the NaCl in ND96 with choline chloride. The Km for Na+ was determined in individual oocytes at two different concentrations of alanine (0.1 and 1 mm). The currents are normalized to the maximum current observed in an individual oocyte at ND6 (I/IND6) or at 0.1 mmalanine (I/I0.1A); n= 3 for all.