title: Purification, characterization and molecular modelling of two toxin-like proteins from the Androctonus australis Hector venom.
abstract: Two toxin-like proteins (AahTL1 and AahTL3) were purified from the venom of the scorpion Androctonus australis Hector (Aah). AahTL1 and AahTL3 are the first non toxic proteins cross-reacting with AahI toxins group which indicates that these proteins can be used as a model of vaccins. In order to study structure-function relationships, their complete amino-acid sequences (66 residues) were determined, by automated Edman degradation. They show more than 50% of similarity with both AahI and AahIII antimammal toxins. Three-dimensional structural models of AahTL1 and AahTL3 constructed by homology suggest that the two proteins are structurally similar to antimammal scorpion alpha-toxins specific to voltage dependent Na+ channels. The models showed also that amino-acid changes between potent Aah toxins and both AahTL1 and AahTL3 disrupt the electrostatic potential gradient at their surface preventing their interaction with the receptor, which may explain their non toxicity.
authors.affiliation: Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, Tunisia. najet.abid@pasteur.rns.tn
authors.forename: N
authors.initials: N
authors.lastname: Srairi-Abid
authors.forename: P
authors.initials: P
authors.lastname: Mansuelle
authors.forename: T
authors.initials: T
authors.lastname: Mejri
authors.forename: H
authors.initials: H
authors.lastname: Karoui
authors.forename: H
authors.initials: H
authors.lastname: Rochat
authors.forename: F
authors.initials: F
authors.lastname: Sampieri
authors.forename: M
authors.initials: M
authors.lastname: El Ayeb
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D008958:Models, Molecular; D008969:Molecular Sequence Data; D012604:Scorpion Venoms / Q000737:chemistry* / Q000302:isolation & purification* / Q000633:toxicity; D012605:Scorpions; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity
chemical_list: C414757:AahTL1 toxin; C414758:AahTL3 toxin; D012604:Scorpion Venoms