Figure 7. Methionine oxidation affects hERG channel function.

A, time course of tail current reduction induced by extracellular application of 300 μm ChT to HEK293 cells expressing hERG1a and the indicated mutants thereof. B, relative remaining currents 100 s after ChT application (I₁₀₀) were: hERG1a, 17 ± 5% (n = 8); 3M, 32 ± 3% (n = 5); C723S, 42 ± 3% (n = 6); 3M/C723S, 61 ± 5% (n = 5). *P < 0.05; **P < 0.01. Significances: WT vs. 3M: P = 0.024; C723S vs. 3M/C723S: P = 0.0097. The bath solution contained (in mm): 140 NaCl, 10 KCl, 2 CaCl₂, 2 MgCl₂, 10 Hepes (pH 7.4 with NaOH); holding potential for the wild type and C723S was −100 mV, for 3M and 3M/C723S it was −120 mV.