title: Biochemical and physiological characterization of a new Na(+)-channel specific peptide from the venom of the Argentinean scorpion Tityus trivittatus.
abstract: A new peptide with 61 amino acids cross-linked by 4 disulfide bridges, with molecular weight of 6938.12Da, and an amidated C-terminal amino acid residue was purified and characterized. The primary structure was obtained by direct Edman degradation and sequencing its gene. The peptide is lethal to mammals and was shown to be similar (95% identity) to toxin Ts1 (gamma toxin) from the Brazilian scorpion Tityus serrulatus; it was named Tt1g (from T. trivittatus toxin 1 gamma-like). Tt1g was assayed on several sub-types of Na(+)-channels showing displacement of the currents to more negative voltages, being the hNav1.3 the most affected channel. This toxin displays characteristics typical to the β-type sodium scorpion toxins. Lethality tests and physiological assays indicate that this peptide is probably the most important toxic component of this species of scorpion, known for causing human fatalities in the South American continent.
authors.affiliation: Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico.
authors.forename: Fredy I V
authors.initials: FI
authors.lastname: Coronas
authors.affiliation: Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico.
authors.forename: Elia
authors.initials: E
authors.lastname: Diego-García
authors.affiliation: Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico.
authors.forename: Rita
authors.initials: R
authors.lastname: Restano-Cassulini
authors.affiliation: Laboratorio de Toxinopatología, Centro de Patología Experimental y Aplicada, Facultad de Medicina, Universidad de Buenos Aires and Ministerio de Salud de la Nación, Argentina. Electronic address: aderoodt@gmail.com.
authors.forename: Adolfo R
authors.initials: AR
authors.lastname: de Roodt
authors.affiliation: Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Mexico. Electronic address: possani@ibt.unam.mx.
authors.forename: Lourival D
authors.initials: LD
authors.lastname: Possani
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001118:Argentina; D060829:Arthropod Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001483:Base Sequence; D057809:HEK293 Cells; D006801:Humans; D007928:Lethal Dose 50; D051379:Mice; D008969:Molecular Sequence Data; D062552:NAV1.3 Voltage-Gated Sodium Channel / Q000378:metabolism; D012604:Scorpion Venoms / Q000737:chemistry*; D012605:Scorpions / Q000737:chemistry*; D026941:Sodium Channel Blockers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D015222:Sodium Channels / Q000378:metabolism
chemical_list: D060829:Arthropod Proteins; D062552:NAV1.3 Voltage-Gated Sodium Channel; C424715:SCN3A protein, human; D012604:Scorpion Venoms; D026941:Sodium Channel Blockers; D015222:Sodium Channels
keywords: Na(+)-channel peptide; Primary structure; Scorpion; Tityus; cDNA cloning; β-Toxin