This recombinant peptide reversibly and dose-dependently inhibits the transient outward potassium current (I(To)) of rabbit atrial myocyte and prolongs the action potential duration of rabbit atrial myocyte without affecting the action potential amplitude. Thus, the voltage-gated potassium channels Kv4.1/KCND1, Kv4.2/KCND2, Kv4.3/KCND3 may be the target of this toxin. Expressed by the venom gland. Belongs to the long chain scorpion toxin family. Class 2 subfamily. It is uncertain whether Met-1 or Met-2 is the initiator.