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1h5o
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(New page: 200px<br /><applet load="1h5o" size="450" color="white" frame="true" align="right" spinBox="true" caption="1h5o" /> '''SOLUTION STRUCTURE OF CROTAMINE, A NEUROTOXI...)
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Revision as of 14:18, 20 November 2007
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SOLUTION STRUCTURE OF CROTAMINE, A NEUROTOXIN FROM CROTALUS DURISSUS TERRIFICUS
Overview
Crotamine 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.
About this Structure
1H5O is a Single protein structure of sequence from Crotalus durissus terrificus. Full crystallographic information is available from OCA.
Reference
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
Page seeded by OCA on Tue Nov 20 16:25:40 2007
