Quantitative comparisons of current modifications by MTS reagents along the lateral window. (A) Superimposed current traces of T336C recorded in response to ATP without (black) and with (blue) MTSET application (blue bar) using a 2-min interval between traces to illustrate how modification is quantified. Traces were scaled using the current amplitude 1.5 s after ATP application. Percent modification was calculated according to: modification (%) = [(b/a)−1] × 100, where b is the normalized current after a 6-s MTSET application, and a is the current at the corresponding time in the control trace. (B) Averaged current modifications by MTSET (left) or MTS-TPAE (right) at each Cys mutant (n = 3–9). Error bars are SEM. Orange bars indicate positions where current reduction or potentiation was observed.