Lipid-mediated hydrophobic gating in the BK potassium channel.

ABSTRACT: Structures of the large-conductance, calcium-activated potassium (BK) channel in the Ca²⁺ -bound and Ca²⁺ -free states have suggested that K⁺ conduction is not gated via a steric closure of the pore-lining helices of the channel, in contrast to the gating mechanism of other 6TM channels. This has raised the question of how gating might occur in the absence of apparent steric hindrance by protein residues. To answer this question, we perform molecular simulations and free-energy calculations to develop a microscopic picture of the gating mechanism. Our results highlight an unexpected role for annular lipids, which appear to be an integral part of the gating machinery. In the Ca²⁺ -free ("closed") pore, methyl groups from lipid alkyl chains can ent

SUBMITTER: Coronel L 

PROVIDER: S-EPMC12335557 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature