Table 6.
The conditional burst length distributions, and the distributions of the number of openings per burst, for 100 nm ACh
| Conditional on starting in the diliganded open state | Conditional on starting in the a monoliganded state | Conditional on starting in the b monoliganded open state | Unconditional distribution | |
|---|---|---|---|---|
| Wild-type | ||||
| Mean burst length (ms) | 2.73 | 0.26 | 0.14 | 0.44 |
| φ | 0.1 | 0.37 | 0.53 | — |
| a (%) | ||||
| τ= 0.016 ms | — | — | 81 | 43 |
| τ= 0.274 | — | 100 | — | 37 |
| τ= 0.319 | — | — | 16 | 8 |
| τ= 2.69 | 100 | — | 3 | 11 |
| Mean openings per burst | 5.07 | 1.01 | 1.30 | 1.56 |
| a (%) | ||||
| μ= 1.01 | — | 100 | — | 37 |
| μ= 1.17 | — | — | 97 | 51 |
| μ= 4.93 | 100 | — | 3 | 12 |
| εL78P | ||||
| Mean burst length (ms) | 42.1 | 0.48 | 15.8 | 14.0 |
| φ | 2.7 × 10−3 | 0.12 | 0.88 | — |
| a (%) | ||||
| τ= 0.004 ms | — | — | 2 | 1.3 |
| τ= 0.16 ms | — | 42 | — | 5 |
| τ= 0.46 ms | — | 58 | — | 7 |
| τ= 12 ms | — | — | 77 | 68 |
| τ= 30.6 ms | 100 | — | 21 | 19 |
| Mean openings per burst | 90.9 | 1.59 | 65.9 | 58.3 |
| a (%) | ||||
| μ= 1.26 | — | 99.6 | — | 12 |
| μ= 26.2 | −57 | — | 3 | 3 |
| μ= 67.3 | 157 | 97 | 85 | |
The values are calculated from the microscopic rate constants for wild-type and εL78P receptors that were given in Table 5, without allowance for missed events (the ‘true’ distributions). The upper part of the table shows results for wild-type, and the lower part for εL78P receptors. The overall means are given for each sort of distribution. The φ-values give the predicted probabilities that a burst starts in each of the three open states, and are followed by the components of the distribution. Burst length distributions are all given by a mixture of six exponential pdfs because entry into the unliganded R state was the criterion for the end of a burst). The time constants for the exponential components are identical for the unconditional, and all three conditional distributions, so they are given only once, on the left. It is only the areas that vary from one component to another that are tabulated. Many of these components have effectively zero area (indicated by dash) so only those components with areas greater than 1% are shown here. The distributions of the number of openings per burst are mixtures of three geometric distributions (because there are three open states), and again components with very small area are omitted for simplicity.