title: A potent vasoactive cytolysin isolated from Scorpaena plumieri scorpionfish venom.
abstract: A new vasoactive cytolytic toxin, referred to as Sp-CTx, has been purified from the venom of the scorpionfish Scorpaena plumieri by a combination of gel filtration and anion exchange chromatographies. An estimation of Sp-CTx native molecular mass, performed by size exclusion chromatography, demonstrated that it is a 121 kDa protein. Further physicochemical studies revealed its glycoproteic nature and dimeric constitution, comprising subunits of approximately 65 kDa (MALDI-TOF-MS). Such protein has proved to possess a potent hemolytic activity on washed rabbit erythrocytes (EC(50) 0.46 nM), whose effect was strongly reduced after treatment with antivenom raised against stonefish venom -Synanceja trachynis (SFAV). This cross-reactivity has been confirmed by western blotting. Like S. plumieri whole venom (100 microg/mL), Sp-CTx (1-50 nM) caused a biphasic response on phenylephrine pre-contracted rat aortic rings, characterized by an endothelium- and dose-dependent relaxation phase followed by a contractile phase. The vasorelaxant activity has been abolished by l-NAME, demonstrating the involvement of nitric oxide on the response. We report here the first isolation of a cytolytic/vasoactive protein from scorpionfish venom and the data provided suggest structural and functional similarities between Sp-CTx and previously published stonefish hemolytic toxins.
authors.affiliation: Departamento de Fisiologia e Biofísica, Departamento de Bioquímica e Imunologia, Laboratório de Venenos e Toxinas Animais (LVTA), ICB/UFMG, Av. Antônio Carlos, 6627, 31270-901 Belo Horizonte-MG, Brazil.
authors.forename: F
authors.initials: F
authors.lastname: Andrich
authors.forename: J B T
authors.initials: JB
authors.lastname: Carnielli
authors.forename: J S
authors.initials: JS
authors.lastname: Cassoli
authors.forename: R Q
authors.initials: RQ
authors.lastname: Lautner
authors.forename: R A S
authors.initials: RA
authors.lastname: Santos
authors.forename: A M C
authors.initials: AM
authors.lastname: Pimenta
authors.forename: M E
authors.initials: ME
authors.lastname: de Lima
authors.forename: S G
authors.initials: SG
authors.lastname: Figueiredo
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects; D003603:Cytotoxins / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D004912:Erythrocytes / Q000187:drug effects; D005397:Fish Venoms / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D005400:Fishes, Poisonous; D053878:Hemolytic Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects; D011817:Rabbits; D051381:Rats; D014665:Vasodilator Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity
chemical_list: D003603:Cytotoxins; D005397:Fish Venoms; D053878:Hemolytic Agents; D014665:Vasodilator Agents