RESUMO
Chemical analyses of the hemagglutinating fraction from Scorpaena plumieri venom revealed that it contains five components (Sp-CL 1-5) with similar chromatographic elution profiles (35-38% of acetonitrile), molecular masses (16,800-17,000 Da) and N-terminal sequences, suggesting that they are isoforms of the same protein. The amino acid sequence of Sp-CL4 was determined and shown to have homology with fish C-type lectins. These data demonstrate for the first time the presence of C-type isolectins in a scorpionfish venom.
Assuntos
Venenos de Peixe/química , Lectinas/isolamento & purificação , Perciformes , Sequência de Aminoácidos , Animais , beta-Globulinas/química , beta-Globulinas/isolamento & purificação , Venenos de Peixe/isolamento & purificação , Lectinas/química , Lectinas Tipo C/química , Lectinas Tipo C/isolamento & purificação , Dados de Sequência Molecular , Peso Molecular , Alinhamento de SequênciaAssuntos
Toxicologia , Toxicologia , Biodiversidade , Venenos , Intoxicação , Toxinas Biológicas , ToxicologiaAssuntos
Toxicologia , Toxicologia , Biodiversidade , Venenos , Intoxicação , Toxinas Biológicas , Toxicologia , Alergia e Imunologia , Zoologia , BiodiversidadeRESUMO
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.
