FIGURE 9.
Rectification of level-2 channels simulated by a macroscopic continuum model. The thin solid line indicates the observed I-V curve at pH 6.9 for di-alm and the open circles are the data points for alm. The thick smooth curve is the theoretical calculation using generalized Nernst-Planck equation, Eqs. 1–3 in a previous article (Asami et al., 2002), with the barrier parameters estimated on pages 224–226 of this reference. In the calculation, a hexameric helix bundle is assumed, the dipole moment per helix is 2.4 × 10−28 cm and the total charge due to ionized Glu18 is 0.6e.