CSTX (for "Cupiennius salei toxins") is a name given to a group of closely related neurotoxic peptides present in the venom of the wandering spider Cupiennius salei. There are twenty types so far described for this protein group. However, some are reclassified into cupiennins group of toxin, including CSTX-3, -4, -5, and -6, because of their chemical affinity. The first thirteen were isolated and identified in 1994 by Lucia Kuhn-Nentwig, Johann Schaller, and Wolfgang Nentwig of the Zoological Institute at the University of Bern, Switzerland.[1] The different types are most likely the products of splicing variant of the same gene. They are all L-type calcium channel blockers, and also exhibit cytolytic activity by forming an alpha-helix across the cell membrane in mammalian neurons. They also inhibit voltage-gated calcium channels in insect neurons.[2]
- ^ Kuhn-Nentwig L, Schaller J, Nentwig W (1994). "Purification of toxic peptides and the amino acid sequence of CSTX-1 from the multicomponent venom of Cupiennius salei (Araneae:Ctenidae)". Toxicon. 32 (3): 287–302. Bibcode:1994Txcn...32..287K. doi:10.1016/0041-0101(94)90082-5. PMID 8016851.
- ^ Kuhn-Nentwig L, Schaller J, Nentwig W (2004). "Biochemistry, toxicology and ecology of the venom of the spider Cupiennius salei (Ctenidae)". Toxicon. 43 (5): 543–553. Bibcode:2004Txcn...43..543K. doi:10.1016/j.toxicon.2004.02.009. PMID 15066412.