Purification and characterization of Ts15, the first member of a new α-KTX subfamily from the venom of the Brazilian scorpion Tityus serrulatus

► We isolated and characterized a new toxin from T. serrulatus scorpion venom. ► A wide electrophysiological screening with potassium and sodium channels was carried out. ► The novel toxin named Ts15, preferentially blocks Kv1.2 and Kv1.3. ► Ts15 is the unique member of the new α-Ktx21 subfamily.