Table 2.
Effects of the mutant IpTxa on Psubstate of purified RyR1. Psubstate, max and EC50 for Psubstate of purified RyR1 were calculated as described in the legend to Table 1. Values are means ± SE of 4–10 experiments. The average lengths of the substate events were determined at 30 nM concentration. Asterisks indicate significant differences from the wild type for each parameter (Student t-test, P < 0.05). ND: not determined.
| Psubstate | Mean duration of substate (s) | ||
|---|---|---|---|
| Psubstate, max | EC50 (nM) | ||
| Wild type | 0.86 ± 0.05 | 17.08 ± 2.31 | 3.97 ± 0.18 |
| K8A | 0.85 ± 0.02 | 5.29 ± 4.84* | ND |
| R33A | 0.18 ± 0.06* | 19.25 ± 1.05 | 1.43 ± 0.09* |
| K30A | 0.16 ± 0.05* | 15.66 ± 5.99 | 1.88 ± 0.22* |
| R31A | 0.15 ± 0.02* | 18.23 ± 1.65 | 3.15 ± 0.10* |