A single-channel recording of cysless/344C showing the effect of MTSET. (A) Gating behavior in the presence of 2 mM ATP before modification (left top trace), after modification (left middle trace, blue), and after the reversal of the modification by DTT (left bottom trace) in the same patch. Corresponding all-point histograms (gray bars) and their Gaussian fits (black and blue lines) were plot on the right. (B) The Po, obtained from the traces in A, of the cysless/I344C channel before (black) and after (blue) modification. Those of the cysless/WT (gray) in the presence of 2 mM ATP are included for comparison (traces not depicted). n = 7 for cysless/I344C. n = 6 for cysless/WT. (C) Single-channel amplitude of the cysless/I344C channel before and after modification. Star indicates significant difference as determined by Student’s paired t test; n = 7.