The structure of spider toxin huwentoxin-II with unique disulfide linkage: evidence for structural evolution.Shu, Q., Lu, S.Y., Gu, X.C., Liang, S.P.
(2002) Protein Sci. 11: 245-252
- PubMed: 11790834
- DOI: 10.1110/ps.30502
- PubMed Abstract:
- Purification and Characterization of Huwentoxin-II, a Neurotoxic Peptide from the Venom of the Chinese Bird Spider Selenocosmia huwena
Shu, Q.,Liang, S.P.
(1999) J.PEPT.RES. 53: 486
- Sequence-specific Assignment of 1H-NMR Resonance and Determination of the Secondary Structure of HWTX-II
Shu, Q.,Lu, S.Y.,Gu, X.C.,Liang, S.P.
(2001) ACTA BIOCHIM.BIOPHYS.SINICA 33: 65
- Assignment of Disulfide Bonds of Huwentoxin-II by Edman Degradation Sequencing and Stepwise Thiol Modification
Shu, Q.,Huang, R.H.,Liang, S.P.
() TO BE PUBLISHED --: --
The three-dimensional structure of huwentoxin-II (HWTX-II), an insecticidal peptide purified from the venom of spider Selenocosmia huwena with a unique disulfide bond linkage as I-III, II-V, and IV-VI, has been determined using 2D (1)H-NMR. The resul ...
The three-dimensional structure of huwentoxin-II (HWTX-II), an insecticidal peptide purified from the venom of spider Selenocosmia huwena with a unique disulfide bond linkage as I-III, II-V, and IV-VI, has been determined using 2D (1)H-NMR. The resulting structure of HWTX-II contains two beta-turns (C4-S7 and K24-W27) and a double-stranded antiparallel beta-sheet (W27-C29 and C34-K36). Although the C-terminal double-stranded beta-sheet cross-linked by two disulfide bonds (II-V and IV-VI in HWTX-II, II-V and III-VI in the ICK molecules) is conserved both in HWTX-II and the ICK molecules, the structure of HWTX-II is unexpected absence of the cystine knot because of its unique disulfide linkage. It suggests that HWTX-II adopts a novel scaffold different from the ICK motif that is adopted by all other spider toxin structures elucidated thus far. Furthermore, the structure of HWTX-II, which conforms to the disulfide-directed beta-hairpin (DDH) motif, not only supports the hypothesis that the ICK is a minor elaboration of the more ancestral DDH motif but also suggests that HWTX-II may have evolved from the same structural ancestor.
Life Science College, Peking University, Beijing 100871, People's Republic of China.