GsAF-II

GsAF-II (also termed Kappa-theraphotoxin-Gr2c) was originally isolated from the venom of Grammostola rosea spider. This peptide toxin has antinociceptive and antiarrhythmic effects in mammals. The peptide is reported to block the following voltage-gated sodium channels: Nav1.1, Nav1.2, Nav1.3, Nav1.4, Nav1.6 and Nav1.7 with IC50 values of, respectively, 5.7, 12, 24, 4, 6.6 and 1.3 µM. This peptide also blocks hERG1 with an IC50 value of 4.7 µM.