Figure 6.
αR350W has an increased channel open probability. A, representative traces of single channel recordings from oocytes expressing WT αβγ, αV351Aβγ, and αR350Wβγ. Cell-attached patches were performed at −80 mV (opposite to pipette potential) with a NaCl-110 bath solution and a pipette solution containing 110 mm LiCl. C and O represent closed and open states. Recordings were further filtered at 20 Hz with a low-pass Gaussian following 100 Hz of low-pass Gaussian algorithm by ClampFit 10 (Molecular Devices) for display. The filtering did not eliminate transitions, as judged by visual inspection. B, single channel conductances of WT and the two variants, determined by linear regression of unitary currents and clamping voltages in the range of −20 to −100 mV. Values were not significantly different (p > 0.05, one-way ANOVA). C, NPo as the product of N (channel number in patches) and Po (open probability) of WT and the mutant channels. D, N (channel numbers) of WT and mutant channels. E, Po of WT and mutant channels. B–E, data are shown as dot plots with mean and S.D. as bars. Significantly different values in C–E are noted (p < 0.05, one-way ANOVA followed with a Dunnett's post hoc test). NS, not significant.