Skip to main content
. Author manuscript; available in PMC: 2012 Apr 23.
Published in final edited form as: Circulation. 2007 Jun 25;116(2):134–142. doi: 10.1161/CIRCULATIONAHA.106.659086

Figure 3.

Figure 3

Functional characterization of L179F in HEK293 cells stably transfected with SCN5A-encoded Nav1.5 α-subunit. A, Representative traces of sodium channel current recorded with the whole-cell configuration of the patch-clamp technique for a clamp step from −140 mV to various potentials. Current amplitude and time course are shown on each panel for the sodium channel alone, sodium channel plus WT-β4, and sodium channel plus β4 mutant. No significant differences in amplitude or current/time course were noted (Summary data in Table 2). B, Steady-state voltage dependence of activation (right plot) and inactivation (left plot) with and without WT-β4 or L179F-β4. Data are means of measurements, and the lines are Boltzmann fits with n numbers and parameters of the fit found in Table 2. C, Detail of the “window” current where the activation curves overlap the inactivation curves. L179F increases window current. INa indicates robust sodium current; GNa, sodium conductance (calculated from peak sodium current [INa] divided by the driving force [V–Na reversal potential]).