Isolation and Characterization of CvIV4: A Pain Inducing α- Scorpion Toxin
A. CvIV4 (1 µM) slowed the fast inactivation of isoforms Nav1.2, Nav1.3, Nav1.4 and Nav1.7 expressed in human embryonic kidney cells (HEK). In contrast, CvIV4 had a minimal effect on Nav1.5 (expressed in HEK) and no effect on neuronal TTX-R sodium current isolated from adult rat dorsal root ganglia (DRG) neurons (500 nM TTX was used to block TTX-S sodium current). All sodium current traces were elicited by depolarizing to −10 mV from a holding potential of −100 mV. B. Dose-response curves for CvIV4 slowing the fast inactivation of five sodium channel isoforms (Nav1.2–1.7).