Journal: bioRxiv

Article Title: The structural mechanism of eukaryotic fluoride channel activation and inhibition by monovalent cations

doi: 10.64898/2026.04.21.719972

Figure Lengend Snippet: (A) Left, cryo-EM map of the FEX-CA/10E8v4 Fab complex. Right, atomic model of FEX-CA/10E8v4 Fab complex. For both panels, FEX-CA is shown in yellow, the 10E8v4 Fab heavy chain in salmon pink, and the light chain in green. Dashed lines indicate the approximate boundaries of the plasma membrane, with the cytoplasmic (in) and extracellular (out) sides labeled. (B) Structural comparison of FEX-CA in the presence of NaCl and LiCl analyzed using Resi-Ruler . Domain 1 of the Na⁺ and Li⁺ structures are superimposed and the magnitude of the per-residue C α distance differences is displayed as a color gradient (purple, Na + -FEX-CA; orange, Li + -FEX-CA). (C-D). Cross-sectional views of FEX-CA structures determined with Li⁺ (top) or Na⁺ (bottom). Cavities of the functional pore are shown from the extracellular view (C) or side (D), with cross-sectional regions at the same level, as indicated by yellow dashed lines. Protein surfaces of FEX-CA are colored by electrostatic potential as shown in the scale.

Article Snippet: Lysate was extracted with 2% n-Dodecyl-β-D-Maltoside (DDM) (Anatrace, Maumee, OH) for 2 hours at room temperature and protein purified using Strep-Tactin XT 4Flow resin (IBA Lifescience, Pittsburgh, PA) equilibrated with wash buffer (20 mM Tris-HCl, pH 8.0, 100 mM NaCl, 5 mM NaF, 1 mM DDM) followed by size-exclusion chromatography (SEC) (Superdex 200, Cytiva, Marlborough, MA) in SEC buffer (20 mM 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES) pH 7.5, 150 mM LiCl, 5 mM NaF, and 0.5 mM DDM for cryo-EM or 1 mM DDM for functional studies.

Techniques: Cryo-EM Sample Prep, Clinical Proteomics, Membrane, Labeling, Comparison, Residue, Functional Assay

Journal: bioRxiv

Article Title: The structural mechanism of eukaryotic fluoride channel activation and inhibition by monovalent cations

doi: 10.64898/2026.04.21.719972

Figure Lengend Snippet: (A) Size exclusion chromatograms of MPER-tagged FEX-CA alone (gray dashed line) or with 10E8v4 Fab at a 1:1 molar ratio (blue trace) in the presence of 150 mM LiCl. Inset: Coomassie-stained SDS-PAGE of the peak fraction corresponding to the FEX-CA/10E8v4 Fab complex. (B) Representative cryo-EM micrograph and 2D averages of the FEX-CA/10E8v4 Fab complex in DDM micelles, with a 100 Å scale bar indicated. (C) Fourier shell correlation (FSC) curves as a function of resolution calculated between the half maps. (D) Local resolution map colored by local resolution estimate (B factor -137.8) using cryoSPARC. (E) Particle angular distribution plot.

Article Snippet: Lysate was extracted with 2% n-Dodecyl-β-D-Maltoside (DDM) (Anatrace, Maumee, OH) for 2 hours at room temperature and protein purified using Strep-Tactin XT 4Flow resin (IBA Lifescience, Pittsburgh, PA) equilibrated with wash buffer (20 mM Tris-HCl, pH 8.0, 100 mM NaCl, 5 mM NaF, 1 mM DDM) followed by size-exclusion chromatography (SEC) (Superdex 200, Cytiva, Marlborough, MA) in SEC buffer (20 mM 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES) pH 7.5, 150 mM LiCl, 5 mM NaF, and 0.5 mM DDM for cryo-EM or 1 mM DDM for functional studies.

Techniques: Staining, SDS Page, Cryo-EM Sample Prep