Figure 2. The inhibition effect of iberiotoxin on BK channels (a+β1) could be enhanced after deglycosylation of β1 subunit. (A) Representative whole cell current traces from HEK 293T cells expressing wild-type BK channels (a+β1) before and after the application of IbTx 100 nM. The holding voltage was -80 mV and the currents were elicited by a pulse of +100 mV in the presence of 300 nM free Ca²⁺ in the pipette solution. (B) Representative whole cell current traces from HEK 293T cells expressing mutant BK channels N80A/N142A before and after the application of IbTx 100 nM. (C) Representative whole cell current traces from HEK 293T cells expressing mutant BK channels N80Q/N142Q before and after the application of IbTx 100 nM. (D) Statistical analysis of pharmacological modulation of wild-type BK channels (a+β1) (n = 7) and N80A/N142A (n = 7, ***p ＜ 0.001) or wild-type BK channels (a+β1) (n = 7) and N80Q/N142Q (n = 6, ^###p ＜ 0.001) by IbTx 100 nM. The inhibition ratios of IbTx on the currents of N80A/N142A and N80Q/N142Q were not significantly different (p ＞ 0.05).