Dual-function toxin that completely inhibits the activity of trypsin at a molar ratio of 1:1 (dissociation constant of 107 nM) and that inhibits mKv1.3/KCNA3 potassium channel currents with an IC(50) of 6.2 nM (where 1 uM inhibits 80% of currents). Also has weak inhibitory activity against mKv1.1/KCNA1 (where 1 uM inhibits less than 50% of currents), hKv1.2/KCNA2 (where 1 uM inhibits less than 50% of currents), and hKCa2.3/KCNN3. Expressed by the venom gland. Has no effect on chymotrypsin, nor elastase, nor the KCa1.1/KCNMA1 potassium channel. Belongs to the venom Kunitz-type family. Scorpion delta-Ktx subfamily. Delta-Ktx 1 sub-subfamily.