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. Author manuscript; available in PMC: 2014 Jan 10.
Published in final edited form as: Mol Pharmacol. 2008 Mar 27;73(6):1709–1721. doi: 10.1124/mol.108.045591

Fig. 8.

Fig. 8

BeKm-1 potentiated the activator effect of PD307243 but suppressed the activator effect of NS1643. A, cartoon of hERG pore domain with an extracellular BeKm-1 structure. Three hERG subunits are depicted, with the fourth one closest to viewers removed to reveal the narrow selectivity filter and wide inner cavity of the pore. Cylinders represent the S5-P helices. B, main plot, two time courses of changes in hERG current amplitude before and after exposure to 20 μM PD. Current amplitudes were measured from time-dependent currents during 1-s steps to 0 mV and normalized by the current right before PD application. One experiment (open symbols) was conducted in the absence of BeKm-1. The other (black symbols) was conducted in the presence of 10 μM BeKm-1. Inset, the complete time course of the second experiment. BeKm-1 suppressed the current by 80% and subsequent application of PD in the continuous presence of BeKm-1 effectively increased the current amplitude. C, NS (30 μM) effect on hERG in the absence or presence of BeKm-1. The format is the same as that of B. D, data summary. *, p < 0.05, data obtained in the presence of BeKm-1 versus those without BeKm-1.