title: Purification and primary structure determination of Tf4, the first bioactive peptide isolated from the venom of the Brazilian scorpion Tityus fasciolatus.
abstract: In the present study Tityus fasciolatus crude venom toxicity was evaluated and we also report the purification and characterization of a 6.6 kDa neurotoxin isolated from T. fasciolatus venom. This new toxin, named Tf4, has a molecular mass of 6614Da and its primary structure is homologous to TbIT-I from T. bahiensis and TsTX-VI and TsNTxP from T. serrulatus. Tf4 delays frog sodium channel inactivation reversibly, but it is non-toxic to mammals or crustaceans. An attempt to identify the residues responsible for the partial loss of toxicity in Tf4 was carried out based on homology modeling and sequence comparison.
authors.affiliation: Laboratório de Toxinologia, Módulo 05, ICC Ala Sul, Subsolo, Departamento de Ciências Fisiológicas/IB, Universidade de Brasília, Brasília/DF, Brazil CEP 70.910-900.
authors.forename: Simone
authors.initials: S
authors.lastname: Wagner
authors.forename: Mariana S
authors.initials: MS
authors.lastname: Castro
authors.forename: João Alexandre R G
authors.initials: JA
authors.lastname: Barbosa
authors.forename: Wagner
authors.initials: W
authors.lastname: Fontes
authors.forename: Elisabeth N F
authors.initials: EN
authors.lastname: Schwartz
authors.forename: Antonio
authors.initials: A
authors.lastname: Sebben
authors.forename: Osmindo
authors.initials: O
authors.lastname: Rodrigues Pires
authors.forename: Marcelo V
authors.initials: MV
authors.lastname: Sousa
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Schwartz
mesh_terms: D000200:Action Potentials / Q000187:drug effects*; D000595:Amino Acid Sequence; D000818:Animals; D003445:Crustacea; D051379:Mice; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity*; D011892:Rana catesbeiana; D051381:Rats; D012584:Sciatic Nerve / Q000187:drug effects; D012604:Scorpion Venoms / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity*; D012605:Scorpions; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D009498:Neurotoxins; D012604:Scorpion Venoms