Two Novel Toxins from the Venom of the Scorpion Pandinus imperator Show that the N-terminal Amino Acid Sequence is Important for their Affinities towards Shaker B K+ Channels

  title={Two Novel Toxins from the Venom of the Scorpion Pandinus imperator Show that the N-terminal Amino Acid Sequence is Important for their Affinities towards Shaker B K+ Channels},
  author={Froyl{\'a}n G{\'o}mez-Lagunas and Timoteo Olamendi‐Portugal and Fernando Z. Zamudio and Lourival Domingos Possani},
  journal={The Journal of Membrane Biology},
Abstract. Two novel peptides were purified from the venom of the scorpion Pandinus imperator, and were named Pi2 and Pi3. Their complete primary structures were determined and their blocking effects on Shaker B K+ channels were studied. Both peptides contain 35 amino acids residues, compacted by three disulfide bridges, and reversibly block the Shaker B K+ channels. They have only one amino acid changed in their sequence, at position 7 (a proline for a glutamic acid). Whereas peptide Pi2… 
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