title: Purification and cDNA cloning of a novel neurotoxic peptide (Acra3) from the scorpion Androctonus crassicauda.
abstract: Androctonus crassicauda is one of the Southeastern Anatolian scorpions of Turkey with ethno-medical and toxicological importance. Two toxic peptides (Acra1 and Acra2) were isolated and characterized from the venom of this scorpion. In this communication, the isolation of an additional toxin (Acra3) by chromatographic separations (HPLC and TSK-gel sulfopropyl) and its chemical and functional characterization is reported. Acra3 is a 7620Da molecular weight peptide, with 66 amino acid residues crosslinked by four disulfide bridges. The gene coding for this peptide was cloned and sequenced. Acra3 is anticipated to undergo post-translational modifications at the C-terminal region, having an amidated serine as last residue. Injection of Acra3 induces severe neurotoxic events in mice, such as: excitability and convulsions, leading to the death of the animals within a few minutes after injection. Electrophysiological assays conducted with pure Acra3, using cells that specifically expressed sodium channels (Nav1.1-Nav1.6) showed no clear effect. The exact molecular target of Acra3 remained undiscovered, similar to three other scorpion peptides that clustered very closely in the phylogenetic tree included here. The exact target of these four peptides is not very clear.
authors: Department of Biology, Faculty of Science and Art, Eskisehir Osmangazi University, 26480 Eskisehir, Turkey.
authors: Figen
authors: F
authors: Caliskan
authors: Blanca I
authors: BI
authors: García
authors: Fredy I V
authors: FI
authors: Coronas
authors: Rita
authors: R
authors: Restano-Cassulini
authors: Ferhan
authors: F
authors: Korkmaz
authors: Yalcin
authors: Y
authors: Sahin
authors: Gerardo
authors: G
authors: Corzo
authors: Lourival D
authors: LD
authors: Possani
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D056148:Chromatography, Reverse-Phase; D003001:Cloning, Molecular; D017124:Conserved Sequence; D003445:Crustacea; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D006135:Gryllidae; D006801:Humans; D007928:Lethal Dose 50; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology / Q000633:toxicity; D010802:Phylogeny; D012604:Scorpion Venoms / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology / Q000633:toxicity; D012605:Scorpions / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D010455:Peptides; D012604:Scorpion Venoms