Figure 3. Inhibition of BKCa channels by a CaM-binding peptide.
A shows macroscopic currents recorded during voltage clamp steps from −90 to +180 mV in the presence of 3 μm cytoplasmic free calcium. Addition of a CaM-binding peptide (CK219–317) derived from the autoregulatory domain of CaM kinase II (Payne et al. 1988) to the cytoplasmic face of the excised patch produced a dose-dependent decrease in both outward and inward current amplitude (B and C). Conductance-voltage relations derived from tail current data in the absence and presence of CK291–317 are shown in D.