Figure 6. Mutant and hybrid αY93F and αW149F receptors activated by 10 mm TMA.
Single-channel activity and open and closed time histograms from the αY93F mutant (A) and hybrid (B) receptors, and αW149F mutant (C) and hybrid (D) receptors. For the αY93F mutant receptor, no clusters were detected at 10 mm TMA; an episode of 1200 ms in duration is shown. For the rest, a representative single-channel cluster is shown. The values within open and closed time histograms are results of fits to a single exponential. E, an effective opening rate (β') versus[TMA] for the αY93F and αW149F hybrid receptors. Each point represents data from one patch. The number of events per patch was 459-7378 (αY93F) and 598-4518 (αW149F). The continuous lines are fits to eqn (1). The concentration-response parameters are shown in Table 4.