Fig. 4

Predicted amphiphilic α-helices in Sp-CTx α- and β-subunits. Two potential amphiphilic α-helices were predicted by Helical Wheel Projections by Schiffer-Edmundson [39, 40]. Residues are colored according to their chemical character as follows: acidic (blue), basic (red), uncharged polar (green) and nonpolar (yellow). a Amphiphilic α-helix from Ile275 to Asp292 in Sp-CTx-α subunit; b Amphiphilic α-helix from Cys300 to Val311 in the Sp-CTx-β subunit