|PROSITE documentation PDOC60022 [for PROSITE entry PS60022]|
The spider venoms often contain many active peptides such as neurotoxins, lectins, inhibitors to enzyme, etc. These peptides are very important for spider's hunting and defending. During the long history of spider evolution, the peptides evolved into different structures and functions. The following peptides share high similarity and belong to the huwentoxin-2 family [1,2,3,4]:
Peptides of the huwentoxin-2 family contain 6 cysteine residues involved in three disulfide bonds. The three disulfid bridges of HWTX-II have been assigned as C1-C3, C2-C5 and C4-C6 . The structure of HWTX-II contains two β-turns and a double stranded antiparallel β-sheet cross-linked by two disulfide bonds (2-5 and 4-6) (see <PDB:1I25>). Due to its unique 1-3,2-5,4-6 disulfide bond-pairing, HTWX-II does not form a cystine-knot like other spider toxins .
We developed a pattern for huwentoxin-2 family proteins, which contains the six conserved cysteines.Expert(s) to contact by email:
August 2005 / First entry.
PROSITE method (with tools and information) covered by this documentation:
|Title||An overview of peptide toxins from the venom of the Chinese bird spider Selenocosmia huwena Wang [=Ornithoctonus huwena (Wang)].|
|2||Authors||Diao J. Lin Y. Tang J. Liang S.|
|Title||cDNA sequence analysis of seven peptide toxins from the spider Selenocosmia huwena.|
|3||Authors||Shu Q. Huang R. Liang S.-P.|
|Title||Assignment of the disulfide bonds of huwentoxin-II by Edman degradation sequencing and stepwise thiol modification.|
|Source||Eur. J. Biochem. 268:2301-2307(2001).|
|4||Authors||Shu Q. Lu S.-Y. Gu X.-C. Liang S.-P.|
|Title||The structure of spider toxin huwentoxin-II with unique disulfide linkage: evidence for structural evolution.|
|Source||Protein Sci. 11:245-252(2002).|