PROSITE documentation PDOC00435
Myotoxins family signature and profile


Myotoxins [1,2] are small basic peptides (42 to 45 residues) from the venom of rattlesnakes that cause severe muscle necrosis by a non-enzymatic mechanism. Myotoxins act extremely rapidly and serve two primary biological functions: limiting the flight of prey by causing instantaneous paralysis of the hind limbs and promoting rapid death by paralysis of the diaphragm.

Myotoxins contain six cysteines involved in three disulfide bonds as shown in the following schematic representation:

                    |                  |
             |             |                 ||
'C': conserved cysteine involved in a disulfide bond.
'+': conserved basic residue (Arg, Lys, or His).

The structure of all known myotoxins is very conserved. We chose to build a pattern based solely on the position of conserved cysteines and basic residues. We also developed a profile that covers the whole myotoxin.

Last update:

December 2007 / Text revised; profile added.


Technical section

PROSITE methods (with tools and information) covered by this documentation:

MYOTOXINS_2, PS51345; Myotoxins family profile  (MATRIX)

MYOTOXINS_1, PS00459; Myotoxins signature  (PATTERN)


1AuthorsGriffin P.R. Aird S.D.
TitleA new small myotoxin from the venom of the prairie rattlesnake (Crotalus viridis viridis).
SourceFEBS Lett. 274:43-47(1990).
PubMed ID2253781

2AuthorsNicastro G. Franzoni L. de Chiara C. Mancin A.C. Giglio J.R. Spisni A.
TitleSolution structure of crotamine, a Na+ channel affecting toxin from Crotalus durissus terrificus venom.
SourceEur. J. Biochem. 270:1969-1979(2003).
PubMed ID12709056

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