• 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). (wikipedia.org)
  • The toxic effect of crotoxin is determined mainly by the phospholipase A2 action of CB. (wikipedia.org)
  • The CB subunit is a phospholipase A2 protein. (wikipedia.org)
  • The C-terminal (C-terminus) of the CB subunit is important for the interaction between both subunits as it interacts with an alpha helix of CA. The CA subunit thereby blocks a part of the enzyme surface of phospholipase A2, resulting in an impossibility to be activated. (wikipedia.org)
  • The different isoforms of both subunits CA and CB can form crotoxin complexes which can be subdivided into two classes: moderately toxic with a high phospholipase A2 activity or more toxic with a lower enzymatic activity. (wikipedia.org)
  • The presynaptic acetylcholine secretion inhibition is caused by the phospholipase A2 activity of the CB subunit. (wikipedia.org)
  • Crotoxin (CTX) is the main toxic compound in the snake venom of the South American rattlesnake, Crotalus durissus terrificus. (wikipedia.org)
  • Crotalus durissus terrificus snake venom and its major toxin, crotoxin or type II PLA2 (CB) subunit of this toxin, modulates immune and inflammatory responses, interfering with the activity of leukocytes. (fapesp.br)
  • Crotoxin was the first proteinic toxin to be crystallized (Protein crystallization). (wikipedia.org)
  • The relation between toxicity and enzym activity is a result of the synergistic manner (Synergy) of action of both subunits. (wikipedia.org)
  • For this the CA subunit enhances the toxicity of the CB subunit while it reduces its enzyme activity and anticoagulant activity. (wikipedia.org)
  • While the presynaptic effect is caused by the CB subunit, it is enhanced by the presence of the CA subunit. (wikipedia.org)
  • The CB subunit induce an inhibitory effect on spreading and phagocytosis in macrophages and decreased the number of circulating blood and lymph lymphocytes. (fapesp.br)
  • 15. Crotoxin: novel activities for a classic beta-neurotoxin. (nih.gov)
  • The interface between CA and CB is formed by three tryptophan amino acids which play an important role in the stability of the crotoxin complex. (wikipedia.org)