Ion permeation, selectivity, and electronic polarization in fluoride channels.

ABSTRACT: Fluoride channels (Flucs) export toxic F^- from the cytoplasm. Crystallography and mutagenesis have identified several conserved residues crucial for fluoride transport, but the permeation mechanism at the molecular level has remained elusive. Herein, we have applied constant-pH molecular dynamics and free-energy-sampling methods to investigate fluoride permeation through a Fluc protein from Escherichia coli. We find that fluoride is facile to permeate in its charged form, i.e., F^-, by traversing through a non-bonded network. The extraordinary F^- selectivity is gained by the hydrogen-bonding capability of the central binding site and the Coulombic filter at the channel entrance. The F^- permeation rate calculated using an electronically polarizable

SUBMITTER: Yue Z 

PROVIDER: S-EPMC9034187 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature