Conotoxin TVIIA, a novel peptide from the venom of Conus tulipa 2. Three-dimensional solution structure.Hill, J.M., Alewood, P.F., Craik, D.J.
(2000) Eur.J.Biochem. 267: 4649-4657
- PubMed: 10903497
- PubMed Abstract:
- Solution structure of the sodium channel antagonist conotoxin GS: a new molecular caliper for probing sodium channel geometry
Hill, J.M.,Alewood, P.F.,Craik, D.J.
(1997) Structure 5: 571
- Conotoxin TVIIA, a novel peptide from the venom of Conus tulipa 1. Isolation, characterisation and chemical synthesis
Hill, J.M.,Atkins, A.R.,Loughnan, M.L.,Jones, A.,Adams, D.A.,Martin, R.,Lewis, R.J.,Craik, D.J.,Alewood, P.F.
(2000) Eur.J.Biochem. 267: 4642
The three-dimensional solution structure of conotoxin TVIIA, a 30-residue polypeptide from the venom of the piscivorous cone snail Conus tulipa, has been determined using 2D 1H NMR spectroscopy. TVIIA contains six cysteine residues which form a 'four ...
The three-dimensional solution structure of conotoxin TVIIA, a 30-residue polypeptide from the venom of the piscivorous cone snail Conus tulipa, has been determined using 2D 1H NMR spectroscopy. TVIIA contains six cysteine residues which form a 'four-loop' structural framework common to many peptides from Conus venoms including the omega-, delta-, kappa-, and muO-conotoxins. However, TVIIA does not belong to these well-characterized pharmacological classes of conotoxins, but displays high sequence identity with conotoxin GS, a muscle sodium channel blocker from Conus geographus. Structure calculations were based on 562 interproton distance restraints inferred from NOE data, together with 18 backbone and nine side-chain torsion angle restraints derived from spin-spin coupling constants. The final family of 20 structures had mean pairwise rms differences over residues 2-27 of 0.18+/-0.05 A for the backbone atoms and 1.39+/-0.33 A for all heavy atoms. The structure consists of a triple-stranded, antiparallel beta sheet with +2x, -1 topology (residues 7-9, 16-20 and 23-27) and several beta turns. The core of the molecule is formed by three disulfide bonds which form a cystine knot motif common to many toxic and inhibitory polypeptides. The global fold, molecular shape and distribution of amino-acid sidechains in TVIIA is similar to that previously reported for conotoxin GS, and comparison with other four-loop conotoxin structures provides further indication that TVIIA and GS represent a new and distinct subgroup of this structural family. The structure of TVIIA determined in this study provides the basis for determining a structure-activity relationship for these molecules and their interaction with target receptors.
Centre for Drug Design and Development, The Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.