1H5O

Solution structure of Crotamine, a neurotoxin from Crotalus durissus terrificus

Summary for 1H5O

• Entry DOI: 10.2210/pdb1h5o/pdb
• Descriptor: Crotamine (1 entity in total)
• Functional Keywords: toxin, sodium channel affecting toxin, venom
• Biological source: Crotalus durissus terrificus (tropical rattlesnake)
• Cellular location: Secreted: Q9PWF3
• Total number of polymer chains: 1
• Total formula weight: 4902.88

Authors

Nicastro, G.,Franzoni, L.,De Chiara, C.,Mancin, C.A.,Giglio, J.R.,Spisni, A. (deposition date: 2001-05-23, release date: 2003-05-09, Last modification date: 2024-12-04)

Primary citation

Nicastro, G.,Franzoni, L.,De Chiara, C.,Mancin, A.C.A.,Giglio, J.R.,Spisni, A.
Solution Structure of Crotamine, a Na+ Channel Affecting Toxin from Crotalus Durissus Terrificus Venom
Eur.J.Biochem., 270:1969-, 2003

PubMed Abstract: 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.

PubMed: 12709056
DOI: 10.1046/J.1432-1033.2003.03563.X

Experimental method

SOLUTION NMR