AmmTX3 is a member of the α-KTX15 family of scorpion toxins which includes 6 homologous peptides found in four species of scorpion venoms -Aa1, AaTX1, AaTX2, AmmTX3, BmTX3 and Discrepin. AmmTx3 shares homology of 94% with Aa1 and 91% with BmTx3 and is originally isolated from the venom of the scorpion Androctonus mauretanicus. This toxin selectively blocks A-type K⁺ channels in cerebellum granular cells or cultured striatum neurons from rat brain.

AmmTx3 is a pore blocker of K_V4.2 and K_V4.3 subunits and requires for its action the expression of the K_V4 associated protein dipeptidyl peptidase-like proteins 6 (DPP6). AmmTX3 structure consists of a single chain of 37 amino acid residues cross-linked by three disulphide bridges^1,2.