PDBsum entry 1h5o

Toxin

PDB id: 1h5o

Contents

Protein chain

42 a.a. *

* Residue conservation analysis

PDB id:

1h5o

Name:

Toxin

Title:

Solution structure of crotamine, a neurotoxin from crotalus durissus terrificus

Structure:

Crotamine. Chain: a. Synonym: crt,myotoxin

Source:

Crotalus durissus terrificus. Tropical rattlesnake. Organism_taxid: 8732. Other_details: venom of the rattlesnake crotalus durissus terrificus

NMR struc:

26 models

Authors:

G.Nicastro,L.Franzoni,C.De Chiara,C.A.Mancin,J.R.Giglio,A.Spisni

Key ref:

G.Nicastro et al. (2003). Solution structure of crotamine, a Na+ channel affecting toxin from Crotalus durissus terrificus venom. Eur J Biochem, 270, 1969-1979. PubMed id: 12709056 DOI: 10.1046/j.1432-1033.2003.03563.x

Date:

23-May-01 Release date: 09-May-03

Protein chain

Q9PWF3  (MYC2_CRODU) -  Crotamine from Crotalus durissus terrificus

Seq: 65 a.a.

Struc: 42 a.a.

DOI no: 10.1046/j.1432-1033.2003.03563.x

Eur J Biochem 270:1969-1979 (2003)

PubMed id: 12709056

Solution structure of crotamine, a Na+ channel affecting toxin from Crotalus durissus terrificus venom.

G.Nicastro, L.Franzoni, C.de Chiara, A.C.Mancin, J.R.Giglio, A.Spisni.

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.

Selected figure(s)

Figure 5.
Fig. 5. Solution structure of crotamine. Stereo view of the 26 NMR models superimposed over the backbone atoms of residues 2–39.

Figure 6.
Fig. 6. Comparison of the electrostatic potential surface between crotamine (A and B), AaHII (PDB accession no. 1PTX) (C and D) and HBD3(PDB accession no. 1KJ6)(E and F). Positively and negatively charged regions are coloured in blue and red, respectively. The orientation in A, C and E is the same as in Fig. 7 Go-. The views in B, D and F result from a 180° rotation of A, C and E around their vertical axis.

The above figures are reprinted by permission from the Federation of European Biochemical Societies: Eur J Biochem (2003, 270, 1969-1979) copyright 2003.

Figures were selected by an automated process.