Blocks voltage-gated non-inactivating potassium channels (Kv) and unblocks inactivating potassium channels blocked by alpha-dendrotoxin in synaptosomes. It is not toxic to mice and crustaceans, but has a paralysing effect on crickets. Expressed by the venom gland. Has the structural arrangement of an alpha-helix connected to a beta-sheet by disulfide bonds (CSalpha/beta). The N-terminus is probably essential for channel affinity. NTX2 has a thousandfold less affinity than NTX, for the potassium channels (Kv) of synaptosomes. In addition, it shows a lower potency (over two logarithm units) than noxiustoxin (AC P08815) in producing 50% blockade of the probability of opening small conductance calcium-activated potassium (KCa) (obtained from cultured bovine aortic endothelial cells). Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 02 subfamily.