GsAF-I

GsAF-I (also termed β-theraphotoxin-Gr1b) was originally isolated from the venom of Grammostola rosea spider. This peptide toxin is reported to block the following voltage-gated sodium channels: Nav1.1, Nav1.2, Nav1.3, Nav1.4, Nav1.6 and Nav1.7 with respective IC50 values of 0.4, 0.6, 1.3, 0.3, 1.2 and 0.04 µM. In addition, the toxin blocks the hERG1 isoform with an IC50 value of 4.8 µM.