Table 1.
Channel characteristics of CyaA-Hly wild type and mutants.
| Toxins a | z b | Hemolytic Activity c | gK (pS) d | Open Lifetime (ms) e | Open Probability f |
|---|---|---|---|---|---|
| WT | −6 | 10.1 ± 1.1% | 36.1 ± 1.7 | 236 ± 1 | 0.29 |
| Q574K | −3 | 35.9 ± 1.0% | 17.1 ± 0.2 | 1620 ± 12 | 0.78 |
| Q574R | −3 | 36.6 ± 0.7% | 22.0 ± 0.3 | 2980 ± 20 | 0.53 |
| Q574E | −9 | 1.6 ± 0.1% | - g | - g | - g |
| E581K | 0 | 35.1 ± 1.1% | 19.3 ± 0.2 | 1920 ± 16 | 0.71 |
| E581R | 0 | 30.0 ± 1.0% | 16.4 ± 0.6 | 2500 ± 14 | 0.82 |
| E581Q | −3 | 32.3 ± 1.0% | 34.7 ± 0.4 | 147 ± 2 | 0.76 |
a Ni2+-NTA purified toxins; b Surface charge of interior pore in trimeric model; c % Hemolytic activities of CyaA-Hly toxins (1 μg/mL) against sheep erythrocytes at 6 h; d The single channel conductance of 1 μg/mL toxins recorded in 1 M KCl solution (pH 7.4), and presented as mean ± SEM from three independent experiments; e The open channel lifetime was calculated from ~100 open events in 1 M KCl solution (pH 7.4) at 100 mV holding potential from equation; N(t)/N(0) = exp(−t/τ); f Open probability was calculated from ~100 open events in 1 M KCl solution (pH 7.4) at 100 mV holding potential from equation Popen = topen/(topen + tclosed); g The event cannot be observed.