PROSITE documentation PDOC60029
Spider toxin CSTX family signature


Spider toxins of the CSTX family are ion channel toxins containing an inhibitor cystine knot (ICK) structural motif or Knottin scaffold (see <PDOC60004>) [E1]. The four disulfide bonds present in the CSTX spider toxin family are arranged in the following pattern: 1-4, 2-5, 3-8 and 6-7.

This family includes:

  • Cupiennius salei (Wandering spider) toxin CSTX-1 and its proteolytic products CSTX-2a and CSTX-2b [1].
  • Cupiennius salei (Wandering spider) CSTX-9 [2].
  • Cupiennius salei (Wandering spider) CSTX-13, a neurotoxic enhancer. In contrast to CSTX-1 and CSTX-9, CSTX-13 is a two-chain peptide with two interchain and two intrachain disulfide bridges [3].

We have developed a pattern that contains the six conserved cysteines with a cysteine arrangement C-C-CC-C-C which are also found in the A chain of CSTX-13.

Expert(s) to contact by email:

Ramakumar S.

Last update:

February 2006 / First entry.


Technical section

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

SPIDER_CSTX, PS60029; Spider toxin CSTX family signature  (PATTERN)


1AuthorsKuhn-Nentwig L. Schaller J. Kaempfer U. Imboden H. Malli H. Nentwig W.
TitleA lysine rich C-terminal tail is directly involved in the toxicity of CSTX-1, a neurotoxic peptide from the venom of the spider Cupiennius salei.
SourceArch. Insect Biochem. Physiol. 44:101-111(2000).
PubMed ID10897091

2AuthorsSchaller J. Kaempfer U. Schuerch S. Kuhn-Nentwig L. Haeberli S. Nentwig W.
TitleCSTX-9, a toxic peptide from the spider Cupiennius salei: amino acid sequence, disulphide bridge pattern and comparison with other spider toxins containing the cystine knot structure.
SourceCell. Mol. Life Sci. 58:1538-1545(2001).
PubMed ID11693532

3AuthorsWullschleger B. Kuhn-Nentwig L. Tromp J. Kaempfer U. Schaller J. Schuerch S. Nentwig W.
TitleCSTX-13, a highly synergistically acting two-chain neurotoxic enhancer in the venom of the spider Cupiennius salei (Ctenidae).
SourceProc. Natl. Acad. Sci. U.S.A. 101:11251-11256(2004).
PubMed ID15272079


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