Inhibits voltage-dependent potassium channels of the Kv1 family (Kv1.1/KCNA1 (Kd=6 nM), Kv1.2/KCNA2 (Kd=15 nM), Kv1.3/KCNA3 (Kd=10-39 nM), Kv1.6/KCNA6, and KCa3.1/KCNN4 (Kd=172 nM)). Monoisotopic mass. LD(50) is 4.5 ug/kg by intracerebroventricular injection into mice. Symptoms observed are trembling of tail, fasciculations, salivation, paralysis and death. Does not act on Kv3.1 up to 125 nM of the toxin (PubMed:9063464). Does not show effect on crabs. Belongs to the sea anemone type 1 potassium channel toxin family. Type 1b subfamily.