Long (4 C-C) scorpion toxin superfamily, Sodium channel inhibitor family, Beta subfamily
toxins bind to site 4 of voltage-gated sodium channels (Nav), specifically the extracellular loop of segments S3-S4 of domain II. These toxins trap segment S4, keeping it in the activated position. This interaction induces a shift in the voltage dependence of Nav activation in the hyperpolarizing direction, and a reduction in the sodium peak amplitude (
Cestele and Catterall, 2000
This group of toxins can be sub-divided into four categories (
Bosmans et al., 2007
toxins that selectively act on mammalian Nav channels (e.g.
toxins that selectively act on insect Nav channels (e.g.
toxins that act on both mammalian and insect Nav channels (e.g.
), and *β
α* toxins that have the primary structure of β-toxins, but exhibit a functional α-effect (e.g.
Long (4 C-C) scorpion toxin superfamily, Sodium channel inhibitor family, Alpha subfamily
Voltage-gated sodium channel impairing toxin
This protein family in
SIB Swiss Institute of Bioinformatics