Table 2.
Current kinetic properties of tethered GABAA receptors
|
|
Activation 10-90% (msec) |
Desensitization |
Deactivation τweight (msec) |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Construct (n) |
τ1 (msec) |
τ2 (msec) |
%A1 |
%A2 |
%C |
||||||
| WT (6) | 4.8 ± 0.6 | 14.9 ± 2.3 | 178 ± 22 | 30 ± 1 | 21 ± 2 | 49 ± 3 | 224 ± 27 | ||||
| Hetβαβ (6) |
6.7 ± 1.0 |
15.7 ± 1.9 |
252 ± 27 |
40 ± 1a
|
25 ± 2 |
35 ± 2a
|
239 ± 15 |
||||
Current kinetic parameters were obtained from tethered wild-type (WT) and Hetβαβ receptors during a 400 msec step into 1 mm GABA. Activation time, weighted deactivation time (τweight), and the desensitization fast (τ1) and intermediate (τ2) time constants as well as the percentage components of fast (%A1), intermediate (%A2), and residual (%C) desensitization were calculated as described in Materials and Methods. The Hetβαβ receptors had significantly larger components of fast desensitization and smaller components of undesensitized receptors compared with wild type.
a
Statistically different from wild type.