The declining current appears to result from a reduction in the number of active channels without a change in their high open probability.
We note that while conductance assays require higher open probability for detection, dye permeability experiments are more sensitive and can detect even a small probability of opening.
Second, the mediation by a higher open probability of voltage-gated Ca2+ channels in response to the depolarizing effect caused by the Kv channel block and an increase of intracellular Ca2+ [8].
It led to high open probability of LTCC but accelerated inactivation and insufficient recovery of LTCC.
MVP is a hyperpolarization-activated K+ channel that displays high open probability at the large cell-negative membrane voltages characteristic of E. coli [ 40].
The first reason is that the proportion of sublevels is tremendously decreased at the higher open probability or more positive voltages such as +60 mV.
However, in contrast to rat, human T-LTCCs had significantly higher open probability than C-LTCCs: P open) at –6.7mV: 0.03±0.002 for T-LTCCs versus 0.017±0.001 for C-LTCCs, P<0.001.
The size-exclusion-purified Cry1Ab 250 kDa oligomers readily incorporate into the bilayer, inducing ion pores with a stable conductance state and high open probability [ 16, 25– 27] for several minutes [ 16].
Its high open probability further shows itself in an extended recording with three channels in the bilayer and from the amplitude histogram of a typical single channel (right panel lower histogram).
Analyses of pore-formation activity in black lipid bilayers of these oligomeric structures showed the induction of stable ion pores with high open probability as reported previously [ 16, 25– 27].
The L97D mutant, on the other hand, mitigates Ca2+ deactivation and maintains a fairly high open probability (Po ∼ 0.4) even in the presence of 3 mM Ca2+, suggesting that this inner helix mutation favors the pore in an open conformation and thereby weakens the inhibitory gating effect of Ca2+.
