FIGURE 1.

Methanethiosulfonate reagent (MTSET) inhibition of D4S6 cysteine mutant. Cells were held at –140 mV and depolarized to –10 mV for 20 ms at 5 s intervals. Currents are shown immediately after whole-cell break-in (P₁) and after 5 min (P₆₀). (A,C) In the absence of reagent the currents increased 29.1 ± 3.6% (n = 15) for wild-type and 21.6 ± 2.6% (n = 9) for Y1767C after 5 min. (B) Including 1 mM MTSET in the patch pipette had no effect on wild-type currents. (D) Internal MTSET inhibited the Y1767C currents by 42.1 ± 4.6% after 5 min.