Table II.
Open- and closed-time components for NMDA receptors comprised of WT or double-cysteine–substituted subunits
| N1/N2A | N1(C,C)/N2A | N1/N2A(C,C) | DTT | |||
| N1/N2A | N1(C,C)/N2A | N1/N2A(C,C) | ||||
| n | 7 | 8 | 9 | 5 | 5 | 4 |
| τO1 | 0.12 ± 0.01 | 0.25 ± 0.05 | 0.45 ± 0.09 | 3.0 ± 2.7 | 1.0 ± 0.7 | 4.7 ± 2.2 |
| aO1 | 6 ± 1.1 | 25 ± 4.7 | 42 ± 9.6 | 10 ± 5.7 | 7.2 ± 1.2 | 17 ± 8.2 |
| τO2 | 8.7 ± 0.9 | 1.6 ± 0.2 | 1.9 ± 0.13 | 26 ± 7 | 17 ± 5.6 | 34 ± 6.9 |
| aO2 | 94 ± 1.1 | 75 ± 4.7 | 59 ± 9.6 | 90 ± 5.7 | 93 ± 1.2 | 83 ± 8.2 |
| τ1 | 0.14 ± 0.01 | 0.25 ± 0.04 | 0.11 ± 0.01 | 0.12 ± 0.01 | 0.13 ± 0.01 | 0.10 ± 0.004 |
| a1 | 20 ± 1.5 | 13 ± 1.3 | 3.7 ± 0.3 | 31 ± 2.8 | 26 ± 3.5 | 31 ± 3.1 |
| τ2 | 1.0 ± 0.1 | 1.7 ± 0.6 | 2.1 ± 0.3 | 0.77 ± 0.16 | 0.8 ± 0.1 | 0.42 ± 0.02 |
| a2 | 24 ± 3.4 | 14 ± 1.6 | 8.7 ± 1.4 | 38 ± 6.9 | 44 ± 5.6 | 37 ± 3.3 |
| τ3 | 4.2 ± 0.4 | 38 ± 8.6 | 56 ± 9.0 | 3.8 ± 1.5 | 2.5 ± 0.4 | 1.1 ± 0.1 |
| a3 | 52 ± 3.4 | 53 ± 3.6 | 48 ± 4.4 | 29 ± 8.6 | 29 ± 8.5 | 30 ± 6.6 |
| τ4 | 27 ± 5.6 | 210 ± 45 | 150 ± 27 | 35 ± 15 | 20 ± 4.9 | 9.1 ± 0.7 |
| a4 | 3.6 ± 1.3 | 17 ± 3 | 33 ± 4.9 | 2.5 ± 1.0 | 1.2 ± 0.3 | 7.0 ± 5.1 |
| τ5 | 1,800 ± 370 | 1,800 ± 310 | 2,900 ± 360 | 1,100 ± 450 | 1,200 ± 680 | 250 ± 52 |
| a5 | 0.13 ± 0.03 | 3 ± 0.9 | 5.7 ± 0.9 | 0.5 ± 0.2 | 0.13 ± 0.03 | 0.13 ± 0.02 |
Mean values (±SEM) for the exponential time constants (τ) and their relative areas (a) of the open- and closed-interval distributions. Idealization and MIL fitting with the sequential NMDA receptor gating model comprising five closed- and two open-channel states was done in QuB (see Materials and methods). These data are shown as ratios relative to WT receptors in Fig. 6.