XB-IMG-124054
Xenbase Image ID: 124054
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Figure 7. Effect of 10 µM CdCl2 on heteromeric channels formed by coexpressing 1:1 mixtures of WT and A43C RNA. (A) Heteromeric channels were treated with 20 µM DTT and washed with Cs-MES, 1.8 mM Ca2+ bath solution before the application of Cd2+ shown in the trace segment. After the reduction of macroscopic currents by treatment with 10 µM CdCl2, currents were restored to 75% of pre-cadmium levels by washing with cadmium-free bath solution. The result is interpreted to indicate that 25% of channels form a high affinity cadmium site that “locks” the channel in a closed conformation (see Results). (B) Comparison of the kinetics of channel activation upon depolarization to 50 mV before (black trace), during (green trace), and after (red trace) the application of Cd2+ in the trace shown in A. The two current traces before Cd2+ were averaged, as were the final two current traces after wash. The green trace is current trace obtained just before wash with Cd2+-free solution. The similarity among normalized traces indicates that the differences in current levels are not a consequence of differences in the kinetics of activation, but most likely reflects the proportion of channels that can be activated by the voltage step. Image published in: Tang Q et al. (2009) © 2009 Tang et al. Creative Commons Attribution-NonCommercial-ShareAlike license Larger Image Printer Friendly View |