The sequence has a large homology with iberiotoxin from Buthus tumulus, charybdotoxin from Leiurus quinquestriatus and noxiustoxin from Centruroides noxius.
An Important site of the toxin is the K27 side chain (a lysine at place 27 of the protein sequence), which enters the pore and protrudes into the selectivity filter of the channel.
[3][2][5][6] These channels control several regulating processes, including neurotransmitter release, heart rate, insulin secretion, smooth muscle contraction.
[8][9][10] The toxin binds to the external vestibule of the channel, and a critical lysine residue (K27), protrudes into the pore and plugs it.
[6][11] These dimensions are remarkably similar to that of the outer vestibule of the KcsA bacterial channel that was determined by X-ray crystallography [12][13][3][14]