Fig. 6.

D110C-CFTR gating was modulated by DTT and cadmium in a manner consistent with the macroscopic results. CFTR variants were activated by 1 mM ATP and 127 U/ml PKA, and recordings were made at V_m = −100 mV. A: single-channel traces of D110C-CFTR activated by intracellular ATP and PKA and standard pipette solution (D110C-CFTR naïve), pipette solution containing 1 mM DTT (D110C-CFTR + DTT), or pipette solution containing 20 μM cadmium after preincubation of the oocyte with 1 mM DTT (D110C-CFTR + Cd²⁺ after DTT), all with corresponding amplitude histograms fit to Gaussian distributions. Bottom trace: expanded representation of the bracketed area in the “D110C-CFTR + Cd²⁺ after DTT” trace. In naïve channels, subconductance (black arrowhead) and full-conductance (gray arrowhead) openings were observed in the same patches. B: mean open burst duration of D110C-CFTR for each condition. *P < 0.05.