- Alomone Labs AmmTx3 Toxin inhibits KV4.2 currents heterologously expressed in Xenopus oocytes.A. Time course of AmmTx3 Toxin (#STA-305) blocking action on KV4.2 currents. Maximum current amplitudes were plotted as a function of time. Membrane potential was held at –90 mV and cells were stimulated by a 120 ms voltage step to 0 mV. 5 µM AmmTx3 Toxin were perfused as indicated by the bar (green) during 280 sec application. B. Superimposed examples of KV4.2 channel current in the absence (control) and presence (green) of 5 µM AmmTx3 Toxin (taken from the experiment in A).
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 KV4.2 and KV4.3 subunits and requires for its action the expression of the KV4 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 bridges1,2.
AmmTx3 Toxin (#STA-305) is a highly pure, synthetic, and biologically active peptide toxin.