Fig. 2

Macroscopic current relaxations for Y1219 and W401 mutants. a Representative traces of Y1219G and W401G macroscopic currents responding to a rapid application and removal of 5 mM ATP. The extended trace marks part of the slow current decay of Y1219G-CFTR after ATP removal. Note that the current traces reveal some minor channel activities supposed to be in a minor gating modes of CFTR [8, 9]. b Macroscopic current relaxations upon ATP wash-out for Y1219G, Y1219I, Y1219F and Y1219W. The current relaxations were fitted with a double exponential function. The time constant and the fraction of the slow component are summarized in Fig. 3. c Single channel recording of Y1219G-CFTR showing a long opening even after ATP removal