Purification and cDNA cloning of a novel neurotoxic peptide (Acra3) from the scorpion Androctonus crassicauda

► Acra3, a novel toxic peptide from Androctonus crassicauda scorpion was isolated. ► The amino acid sequence of Ara3 and a cDNA clone were sequenced. ► Acra3 is neurotoxic to mouse, but non-toxic to insects and crustaceans. ► Although similar to Na-channel affecting peptide has no effect on Nav1.1-Nav1.6. ► Phylogenetic tree clustered Acra3 with other peptide of non-clear functions.