A potent vasoactive cytolysin isolated from Scorpaena plumieri scorpionfish venom.
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.
Andrich
F
F
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.
Carnielli
J B T
JB
Cassoli
J S
JS
Lautner
R Q
RQ
Santos
R A S
RA
Pimenta
A M C
AM
de Lima
M E
ME
Figueiredo
S G
SG
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
D003603:Cytotoxins; D005397:Fish Venoms; D053878:Hemolytic Agents; D014665:Vasodilator Agents