Solution structures of the cis- and trans-Pro30 isomers of a novel 38-residue toxin from the venom of Hadronyche Infensa sp. that contains a cystine-knot motif within its four disulfide bonds

K Johan Rosengren; David Wilson; Norelle L Daly; Paul F Alewood; David J Craik

doi:10.1021/bi011932y

Solution structures of the cis- and trans-Pro30 isomers of a novel 38-residue toxin from the venom of Hadronyche Infensa sp. that contains a cystine-knot motif within its four disulfide bonds

Biochemistry. 2002 Mar 12;41(10):3294-301. doi: 10.1021/bi011932y.

Authors

K Johan Rosengren¹, David Wilson, Norelle L Daly, Paul F Alewood, David J Craik

Affiliation

¹ Institute for Molecular Bioscience, ARC Special Research Centre for Functional and Applied Genomics, University of Queensland, Brisbane QLD 4072, Australia.

PMID: 11876637
DOI: 10.1021/bi011932y

Abstract

The primary sequence and three-dimensional structure of a novel peptide toxin isolated from the Australian funnel-web spider Hadronyche infensa sp. is reported. ACTX-Hi:OB4219 contains 38 amino acids, including eight-cysteine residues that form four disulfide bonds. The connectivities of these disulfide bonds were previously unknown but have been unambiguously determined in this study. Three of these disulfide bonds are arranged in an inhibitor cystine-knot (ICK) motif, which is observed in a range of other disulfide-rich peptide toxins. The motif incorporates an embedded ring in the structure formed by two of the disulfides and their connecting backbone segments penetrated by a third disulfide bond. Using NMR spectroscopy, we determined that despite the isolation of a single native homologous product by RP-HPLC, ACTX-Hi:OB4219 possesses two equally populated conformers in solution. These two conformers were determined to arise from cis/trans isomerization of the bond preceding Pro30. Full assignment of the NMR spectra for both conformers allowed for the calculation of their structures, revealing the presence of a triple-stranded antiparallel beta sheet consistent with the inhibitor cystine-knot (ICK) motif.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
Animals
Base Sequence
Chromatography, High Pressure Liquid
Cystine / chemistry*
DNA Primers
Disulfides / chemistry*
Isomerism
Molecular Sequence Data
Neurotoxins / chemistry*
Neurotoxins / isolation & purification
Nuclear Magnetic Resonance, Biomolecular
Protein Conformation
Sequence Homology, Amino Acid
Solutions
Spider Venoms / chemistry*
Spider Venoms / isolation & purification
Spiders

Substances

DNA Primers
Disulfides
Neurotoxins
Solutions
Spider Venoms
atracotoxin-Hi-OB4219
Cystine

Associated data

PDB/1KQH
PDB/1KQI