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Solution structure of Crotamine, a neurotoxin from Crotalus durissus terrificusSolution structure of Crotamine, a neurotoxin from Crotalus durissus terrificus
Structural highlights
Function[MYXC_CRODU] This toxin specifically modifies voltage-gated sodium channels (Nav), it exhibits analgesic activity and causes severe muscle necrosis by a non-enzymatic mechanism. Moreover, it actively interacts with lipid membranes.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCrotamine is a component of the venom of the snake Crotalus durissus terrificus and it belongs to the myotoxin protein family. It is a 42 amino acid toxin cross-linked by three disulfide bridges and characterized by a mild toxicity (LD50 = 820 micro g per 25 g body weight, i.p. injection) when compared to other members of the same family. Nonetheless, it possesses a wide spectrum of biological functions. In fact, besides being able to specifically modify voltage-sensitive Na+ channel, it has been suggested to exhibit analgesic activity and to be myonecrotic. Here we report its solution structure determined by proton NMR spectroscopy. The secondary structure comprises a short N-terminal alpha-helix and a small antiparallel triple-stranded beta-sheet arranged in an alphabeta1beta2beta3 topology never found among toxins active on ion channels. Interestingly, some scorpion toxins characterized by a biological activity on Na+ channels similar to the one reported for crotamine, exhibit an alpha/beta fold, though with a beta1alphabeta2beta3 topology. In addition, as the antibacterial beta-defensins, crotamine interacts with lipid membranes. A comparison of crotamine with human beta-defensins shows a similar fold and a comparable net positive potential surface. To the best of our knowledge, this is the first report on the structure of a toxin from snake venom active on Na+ channel. Solution structure of crotamine, a Na+ channel affecting toxin from Crotalus durissus terrificus venom.,Nicastro G, Franzoni L, de Chiara C, Mancin AC, Giglio JR, Spisni A Eur J Biochem. 2003 May;270(9):1969-79. PMID:12709056[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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