A Novel Spider Toxin Inhibits Fast Inactivation of the Na_v1.9 Channel by Binding to Domain III and Domain IV Voltage Sensors.

ABSTRACT: Venomous animals have evolved to produce peptide toxins that modulate the activity of voltage-gated sodium (Na_v) channels. These specific modulators are powerful probes for investigating the structural and functional features of Na_v channels. Here, we report the isolation and characterization of δ-theraphotoxin-Gr4b (Gr4b), a novel peptide toxin from the venom of the spider Grammostola rosea. Gr4b contains 37-amino acid residues with six cysteines forming three disulfide bonds. Patch-clamp analysis confirmed that Gr4b markedly slows the fast inactivation of Na_v1.9 and inhibits the currents of Na_v1.4 and Na_v1.7, but does not affect Na_v1.8. It was also found that Gr4b significantly shifts the steady-state activat

SUBMITTER: Peng S 

PROVIDER: S-EPMC8685421 | biostudies-literature | 2021

REPOSITORIES: biostudies-literature