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Myotoxin
Structure of crotamine, a Na+ channel affecting toxin from Crotalus durissus terrificus venom. [1]
Identifiers
SymbolMyotoxins
Pfam PF00819
InterPro IPR000881
PROSITE PDOC00435
SCOP2 1h5o / SCOPe / SUPFAM
Available protein structures:
Pfam   structures / ECOD  
PDB RCSB PDB; PDBe; PDBj
PDBsum structure summary
PDB 1h5oA:1-42

Myotoxins are small, basic peptides found in snake venoms (e.g. rattlesnakes) [2] [3] and lizard venoms (e.g. Mexican beaded lizard). [4] This involves a non-enzymatic mechanism that leads to severe muscle necrosis. These peptides act very quickly, causing instantaneous paralysis to prevent prey from escaping and eventually death due to diaphragmatic paralysis.

The first myotoxin to be identified and isolated was crotamine, from the venom of Crotalus durissus terrificus, a tropical South American rattlesnake, by Brazilian scientist José Moura Gonçalves, in the 1950s. Its biological actions, molecular structure and gene responsible for its synthesis were all elucidated in the last two decades.

References

  1. ^ Nicastro G, Franzoni L, de Chiara C, Mancin AC, Giglio JR, Spisni A (May 2003). "Solution structure of crotamine, a Na+ channel affecting toxin from Crotalus durissus terrificus venom". Eur. J. Biochem. 270 (9): 1969–79. doi: 10.1046/j.1432-1033.2003.03563.x. PMID  12709056.
  2. ^ Griffin PR, Aird SD (1990). "A new small myotoxin from the venom of the prairie rattlesnake (Crotalus viridis viridis)". FEBS Lett. 274 (1): 43–47. doi: 10.1016/0014-5793(90)81325-I. PMID  2253781. S2CID  45019479.
  3. ^ Samejima Y, Aoki Y, Mebs D (1991). "Amino acid sequence of a myotoxin from venom of the eastern diamondback rattlesnake (Crotalus adamanteus)". Toxicon. 29 (4): 461–468. doi: 10.1016/0041-0101(91)90020-r. PMID  1862521.
  4. ^ Whittington, CM; Papenfuss, AT; Bansal, P; Torres, AM; Wong, ES; Deakin, JE; Graves, T; Alsop, A; Schatzkamer, K; Kremitzki, C; Ponting, CP; Temple-Smith, P; Warren, WC; Kuchel, PW; Belov, K (Jun 2008). "Defensins and the convergent evolution of platypus and reptile venom genes". Genome Research. 18 (6): 986–94. doi: 10.1101/gr.7149808. PMC  2413166. PMID  18463304.