5T3M

Solution structure of a triple mutant of HwTx-IV - a potent blocker of Nav1.7


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

The structure, dynamics and selectivity profile of a NaV1.7 potency-optimised huwentoxin-IV variant.

Rahnama, S.Deuis, J.R.Cardoso, F.C.Ramanujam, V.Lewis, R.J.Rash, L.D.King, G.F.Vetter, I.Mobli, M.

(2017) PLoS One 12: e0173551-e0173551

  • DOI: 10.1371/journal.pone.0173551
  • Primary Citation of Related Structures:  
    5T3M

  • PubMed Abstract: 
  • Venom-derived peptides have attracted much attention as potential lead molecules for pharmaceutical development. A well-known example is Huwentoxin-IV (HwTx-IV), a peptide toxin isolated from the venom of the Chinese bird-eating spider Haplopelma schmitdi ...

    Venom-derived peptides have attracted much attention as potential lead molecules for pharmaceutical development. A well-known example is Huwentoxin-IV (HwTx-IV), a peptide toxin isolated from the venom of the Chinese bird-eating spider Haplopelma schmitdi. HwTx-IV was identified as a potent blocker of a human voltage-gated sodium channel (hNaV1.7), which is a genetically validated analgesic target. The peptide was promising as it showed high potency at NaV1.7 (IC50 ~26 nM) and selectivity over the cardiac NaV subtype (NaV1.5). Mutagenesis studies aimed at optimising the potency of the peptide resulted in the development of a triple-mutant of HwTx-IV (E1G, E4G, Y33W, m3-HwTx-IV) with significantly increased potency against hNaV1.7 (IC50 = 0.4 ± 0.1 nM) without increased potency against hNaV1.5. The activity of m3-HwTx-IV against other NaV subtypes was, however, not investigated. Similarly, the structure of the mutant peptide was not characterised, limiting the interpretation of the observed increase in potency. In this study we produced isotope-labelled recombinant m3-HwTx-IV in E. coli, which enabled us to characterise the atomic-resolution structure and dynamics of the peptide by NMR spectroscopy. The results show that the structure of the peptide is not perturbed by the mutations, whilst the relaxation studies reveal that residues in the active site of the peptide undergo conformational exchange. Additionally, the NaV subtype selectivity of the recombinant peptide was characterised, revealing potent inhibition of neuronal NaV subtypes 1.1, 1.2, 1.3, 1.6 and 1.7. In parallel to the in vitro studies, we investigated NaV1.7 target engagement of the peptide in vivo using a rodent pain model, where m3-HwTx-IV dose-dependently suppressed spontaneous pain induced by the NaV1.7 activator OD1. Thus, our results provide further insight into the structure and dynamics of this class of peptides that may prove useful in guiding the development of inhibitors with improved selectivity for analgesic NaV subtypes.


    Organizational Affiliation

    Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD, Australia.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Mu-theraphotoxin-Hs2aA35Haplopelma schmidtiMutation(s): 3 
UniProt
Find proteins for P83303 (Cyriopagopus schmidti)
Explore P83303 
Go to UniProtKB:  P83303
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 
  • OLDERADO: 5T3M Olderado

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Health and Medical Research Council (NHMRC, Australia)Australia1034958

Revision History  (Full details and data files)

  • Version 1.0: 2017-09-06
    Type: Initial release
  • Version 1.1: 2017-09-20
    Changes: Database references
  • Version 1.2: 2017-09-27
    Changes: Author supporting evidence
  • Version 1.3: 2017-11-01
    Changes: Author supporting evidence
  • Version 1.4: 2020-01-08
    Changes: Author supporting evidence, Data collection