Figure 4. Tannic acid antagonizes suppression of CFTR and Kv1.3 currents by SMase C of B.anthracis (BaSMase C).
(A) and (B) Currents of an oocyte injected with cRNA encoding CFTR, which was activated as in Figure 1, before (pre) and after (post) addition of BaSMase C (0.6 ng/μl) without (A) and with (B) 200 nM TA present. (C) Time course of normalized CFTR currents at 50 mV without or with 200 nM TA present in the bath; arrow indicates addition of BaSMase C (mean ± s.e.m, n = 10). (D) and (E) Currents of an oocyte injected with cRNA encoding Kv1.3 before (pre) and after (post) addition of BaSMase C without (D) and with (E) 200 nM TA, elicited by stepping membrane voltage from the −80 mV holding potential to 20 mV and then back to −80 mV. (F) Time course of normalized Kv1.3 currents at 20 mV without or with 200 nM TA in the bath; arrow indicates addition of BaSMase C (mean ± s.e.m, n = 4).