TABLE 1.
Mutant channel properties
| Channel | Surface expressiona | Patch activity | ATP sensitivity (IC50)b | Single channel conductancec |
|---|---|---|---|---|
| % | μm | Picosiemens | ||
| WT | 100 | Yes | 15.4 ± 2.5 | 75 ± 2 |
| N160D | N.D.d | Yes | 102.0 ± 17.1 | ∼75e |
| G156R/N160D | 37 ± 4 | Yes | 21.8 ± 4.3 | 67 ± 1 |
| G156R/N160E | 29 ± 2 | Yes | 12.3 ± 1.7 | 76 ± 2 |
| G156K/N160D | 69 ± 4 | Yes | 47.7 ± 7.3 | 18 ± 2 |
| G156K/N160E | 38 ± 3 | Yes | 7.2 ± 1.5 | 35 ± 3 |
| G156D/N160R | 56 ± 8 | Nof | ||
| G156D/N160K | ND | No | ||
| G156E/N160R | ND | No | ||
| G156E/N160D | ND | No | ||
| G156R/A161D | ND | No | ||
| G156R/L164D | ND | No |
a The value represents the means ± S.E. of 4–10 chemiluminescence experiments.
b ATP sensitivity was determined in K-INT solution containing 1 mm EDTA to minimize rundown; the IC50 values, therefore, tend to be higher than in those reported in studies by others where no EDTA was included in the K-INT solution. The value represents the mean ± S.E. of 4–6 patches.
c Values represent the averaged data of three recordings; error is S.E.
d ND, values not determined.
e Single channel conductance for N160D is from Shyng et al. (31).
f From three-seven patches.