Myotoxin

Last updated
Myotoxin
Crotamin 1H5O.png
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 1h5o A: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.

Related Research Articles

<span class="mw-page-title-main">Venom</span> Toxin secreted by an animal

Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved venom apparatus, such as fangs or a stinger, in a process called envenomation. Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin, and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism.

<span class="mw-page-title-main">Snake venom</span> Highly modified saliva containing zootoxins

Snake venom is a highly toxic saliva containing zootoxins that facilitates in the immobilization and digestion of prey. This also provides defense against threats. Snake venom is injected by unique fangs during a bite, whereas some species are also able to spit venom.

<span class="mw-page-title-main">Envenomation</span> Process of venom injection

Envenomation is the process by which venom is injected by the bite or sting of a venomous animal.

<span class="mw-page-title-main">Disintegrin</span> Proteins from viper venom inhibiting platelets aggregation

Disintegrins are a family of small proteins from viper venoms that function as potent inhibitors of both platelet aggregation and integrin-dependent cell adhesion.

<span class="mw-page-title-main">Convulxin</span>

Convulxin is a snake venom toxin found in a tropical rattlesnake known as Crotalus durissus terrificus. It belongs to the family of hemotoxins, which destroy red blood cells or, as is the case with convulxin, induce blood coagulation.

<i>Crotalus helleri</i> Species of snake

Crotalus helleri or Crotalus oreganus helleri, known as the Southern Pacific rattlesnake, black diamond rattlesnake, and by other names, is a pit viper species or subspecies found in southwestern California and south into Baja California, Mexico, that is known for its regional variety of dangerous venom types. It is sometimes considered a subspecies of Crotalus oreganus.

<span class="mw-page-title-main">Western diamondback rattlesnake</span> Species of snake

The western diamondback rattlesnake or Texas diamond-back is a rattlesnake species and member of the viper family, found in the southwestern United States and Mexico. Like all other rattlesnakes and all other vipers, it is venomous. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the greatest number of snakebites in the U.S. No subspecies are currently recognized.

<i>Crotalus viridis</i> Species of snake

Crotalus viridis is a venomous pit viper species native to the western United States, southwestern Canada, and northern Mexico. Currently, two subspecies are recognized, including the prairie rattlesnake, the nominate subspecies, and the Hopi rattlesnake.

<i>Crotalus durissus</i> Species of snake

Crotalus durissus, known as the South American rattlesnake, tropical rattlesnake, and by other names, is a highly venomous pit viper species found in South America. It is the most widely distributed member of its genus. Currently, seven subspecies are recognized.

<span class="mw-page-title-main">Tiger rattlesnake</span> Species of snake

The tiger rattlesnake is a highly venomous pit viper species found in the southwestern United States and northwestern Mexico. No subspecies are currently recognized. The specific name tigris,, refers to the many narrow dorsal crossbands, which create a pattern of vertical stripes when viewed from the side.

<span class="mw-page-title-main">Crotamine</span>

Crotamine is a toxin present in the venom of the South American rattlesnake. It is a 42-residue long protein containing 11 basic residues and 6 cysteines. It has also been isolated from the venom of North American prairie rattlesnake, Crotalus viridis viridis. It was first isolated and purified by Brazilian scientist José Moura Gonçalves, and later intensively studied by his group of collaborators at the Medical School of Ribeirão Preto of the University of São Paulo.

<i>Crotalus concolor</i> Species of snake

Crotalus concolor, commonly known as the midget faded rattlesnake, faded rattlesnake, and yellow rattlesnake, is a pit viper species found in the western United States. It is a small rattlesnake known for its faded color pattern. Like all other pit vipers, it is venomous.

<span class="mw-page-title-main">Beta defensin</span>

Beta defensins are a family of vertebrate defensins. The beta defensins are antimicrobial peptides implicated in the resistance of epithelial surfaces to microbial colonization.

<span class="mw-page-title-main">Evolution of snake venom</span> Origin and diversification of snake venom through geologic time

Venom in snakes and some lizards is a form of saliva that has been modified into venom over its evolutionary history. In snakes, venom has evolved to kill or subdue prey, as well as to perform other diet-related functions. While snakes occasionally use their venom in self defense, this is not believed to have had a strong effect on venom evolution. The evolution of venom is thought to be responsible for the enormous expansion of snakes across the globe.

Hepatozoon cuestensis is a species of alveolates known to infect snake species such as Crotalus durissus terrificus (rattlesnake).

Hepatozoon cevapii is a species of alveolates protists known to infect snake species such as Crotalus durissus terrificus (rattlesnake).

Hepatozoon massardii is a species of alveolates known to infect snake species such as Crotalus durissus terrificus (rattlesnake).

Crotoxin (CTX) is the main toxic compound in the snake venom of the South American rattlesnake, Crotalus durissus terrificus. Crotoxin is a heterodimeric beta-neurotoxin, composed of an acidic, non-toxic and non-enzymatic subunit (CA), and a basic, weakly toxic, phospholipase A2 protein (CB). This neurotoxin causes paralysis by both pre- and postsynaptic blocking of acetylcholine signalling.

<span class="mw-page-title-main">Snakebites in Latin America</span> Snake Attacks Causing Health Concern

Snakebite envenomation is considered a public health problem in Latin America, with an estimated 70,000 cases annually, but due to underreporting, these numbers may be even higher.

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.