[NMR paper] Sequence-specific 1H-NMR assignment and determination of the secondary structure of hainantoxin-III from the spider Ornithoctonus hainana.

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Sequence-specific 1H-NMR assignment and determination of the secondary structure of hainantoxin-III from the spider Ornithoctonus hainana.

Related Articles Sequence-specific 1H-NMR assignment and determination of the secondary structure of hainantoxin-III from the spider Ornithoctonus hainana.

Protein Pept Lett. 2013 Jul 1;20(7):761-6

Authors: Liu Z, Zhu Q, Hu W, Liang S

Abstract
Hainantoxin-III (HNTX-III) purified from the venom of the spider Ornithoctonus hainana is a novel neurotoxin preferentially inhibiting tetrodotoxin-sensitive voltage-gated sodium channels in rat dorsal root ganglion cells. The structure of this toxin in aqueous solution was investigated using 2-D 1H-NMR techniques. The complete sequencespecific assignments of proton resonances in the 1H-NMR spectra were obtained by analyzing a series of 2-D spectra, including DQF-COSY, TOCSY and NOESY spectra, in H2O or D2O. All the backbone protons and more than 95% of the side-chain protons have been assigned by d?N, d?N, and dNN connectivities in NOESY spectrum. Furthermore, the secondary structure of HNTX-III was identified from NMR data. It consists mainly of a short triple-stranded antiparallel ?-sheet formed by Asp7 to Cys9, Tyr21 to Ser23, and Lys27 to Val30. Because HNTX-III shares high sequence identity (>70%) with HWTX-I and HNTX-I, we proposed that they all share a structural scaffold known as the inhibitor cystine knot architectural motif. This study provides a basis for the further determination of the solution conformation of HNTX-III.


PMID: 22973848 [PubMed - indexed for MEDLINE]



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