Overview
Alomone Labs ShK (Stichodactyla Toxin) inhibits KV1.3 channels heterologously expressed in Xenopus oocytes.A. Time course of ShK (Stichodactyla Toxin) (#STS-400) action on KV1.3 currents. Current amplitude at +35 mV was plotted as a function of time. Membrane potential was held at -80 mV and cells were stimulated by a 100 ms voltage ramp to +40 mV. 0.1 nM for 240 sec (green) and 1 nM for 120 sec (red) Stichodactyla toxin were perfused as indicated by the bars. B. Superimposed examples of KV1.3 channel current in the absence (control) and presence of 0.1 nM (green) and 1 nM (red) Stichodactyla Toxin (taken from the experiment in A).
ShK (Stichodactyla Toxin) is a peptidyl toxin originally isolated from the nematocyst of the sea anemone Stichodactyla helianthus.1
ShK blocks KV1.3, KV1.1, KV1.4, and KV1.6 at subnanomolar concentrations and KV3.2 channels at 1000-fold higher concentration than that required to inhibit KV1.3 channels. It has been shown to block KV current in DRG neurons, to displace radioactive Dendrotoxin from brain synaptosomes1 and inhibit I125-Charybdotoxin binding to Jurkat T lymphocytes with an IC50 of 32 pM.2,4
Evidence also suggests that native KV currents in the central nervous system, which are predominantly carried by KV1.2 channels, are highly sensitive to this toxin.5
A fluorescently labeled synthetic ShK is used to recognize and to sort KV1.3 containing lymphocytes.4,6
