Abstract:
:Studies in Shaker, a voltage-dependent potassium channel, suggest a coupling between activation and inactivation. This coupling is controversial in hERG, a fast-inactivating voltage-dependent potassium channel. To address this question, we transferred to hERG the S3-S4 linker of the voltage-independent channel, rolf, to selectively disrupt the activation process. This chimera shows an intact voltage-dependent inactivation process consistent with a weak coupling, if any, between both processes. Kinetic models suggest that the chimera presents only an open and an inactivated states, with identical transition rates as in hERG. The lower sensitivity of the chimera to BeKm-1, a hERG preferential closed-state inhibitor, also suggests that the chimera presents mainly open and inactivated conformations. This chimera allows determining the mechanism of action of hERG blockers, as exemplified by the test on ketoconazole.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Choveau FS,El Harchi A,Rodriguez N,Louérat-Oriou B,Baró I,Demolombe S,Charpentier F,Loussouarn Gdoi
10.1016/j.bpj.2009.05.060subject
Has Abstractpub_date
2009-09-02 00:00:00pages
1323-34issue
5eissn
0006-3495issn
1542-0086pii
S0006-3495(09)01162-Xjournal_volume
97pub_type
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