Table 3.

Effect of mutations to the lidocaine binding site of ELIC on the time course of desensitization

Channel τdesensitization P-value Number of patches 
 (mean ± SE; ms) (range; ms)   
Wild-type ELIC 4,533 ± 584 2,397–8,026 – 
I266A ELIC 6,324 ± 1,132 2,834–8,081 0.11 
Y14′A ELIC 272 ± 96 146–415 1.5 × 10−3 
Y17′A ELIC 383 ± 64 282–541 4.7 × 10−4 
Y14′A + Y17′A ELICa 112 (56%) – – 
4,820 – 
Channel τdesensitization P-value Number of patches 
 (mean ± SE; ms) (range; ms)   
Wild-type ELIC 4,533 ± 584 2,397–8,026 – 
I266A ELIC 6,324 ± 1,132 2,834–8,081 0.11 
Y14′A ELIC 272 ± 96 146–415 1.5 × 10−3 
Y17′A ELIC 383 ± 64 282–541 4.7 × 10−4 
Y14′A + Y17′A ELICa 112 (56%) – – 
4,820 – 
a

The macroscopic recordings obtained from this double mutant had low peak-current amplitudes. Hence, we averaged 27 responses from 7 different outside-out patches to obtain a proper fit; the desensitization time course was fitted adequately with two exponential components. In an attempt to compare these double-exponential kinetics with the mono-exponential kinetics of the wild type and single mutants, we calculated the corresponding decay half-times. These values were as follows (in ms): 3,142, 189, 265, and 219 for wild-type, Y14′A, Y17′A, and Y14′A + Y17′A ELIC, respectively.

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