2MXM

NMR solution structure of TRTX-Tp1a from the tarantula Thrixopelma pruriens


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with acceptable covalent geometry 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Identification and Characterization of ProTx-III [ mu-TRTX-Tp1a], a New Voltage-Gated Sodium Channel Inhibitor from Venom of the Tarantula Thrixopelma pruriens.

Cardoso, F.C.Dekan, Z.Rosengren, K.J.Erickson, A.Vetter, I.Deuis, J.R.Herzig, V.Alewood, P.F.King, G.F.Lewis, R.J.

(2015) Mol.Pharmacol. 88: 291-303

  • DOI: 10.1124/mol.115.098178

  • PubMed Abstract: 
  • Spider venoms are a rich source of ion channel modulators with therapeutic potential. Given the analgesic potential of subtype-selective inhibitors of voltage-gated sodium (NaV) channels, we screened spider venoms for inhibitors of human NaV1.7 (hNaV ...

    Spider venoms are a rich source of ion channel modulators with therapeutic potential. Given the analgesic potential of subtype-selective inhibitors of voltage-gated sodium (NaV) channels, we screened spider venoms for inhibitors of human NaV1.7 (hNaV1.7) using a high-throughput fluorescent assay. Here, we describe the discovery of a novel NaV1.7 inhibitor, μ-TRTX-Tp1a (Tp1a), isolated from the venom of the Peruvian green-velvet tarantula Thrixopelma pruriens. Recombinant and synthetic forms of this 33-residue peptide preferentially inhibited hNaV1.7 > hNaV1.6 > hNaV1.2 > hNaV1.1 > hNaV1.3 channels in fluorescent assays. NaV1.7 inhibition was diminished (IC50 11.5 nM) and the association rate decreased for the C-terminal acid form of Tp1a compared with the native amidated form (IC50 2.1 nM), suggesting that the peptide C terminus contributes to its interaction with hNaV1.7. Tp1a had no effect on human voltage-gated calcium channels or nicotinic acetylcholine receptors at 5 μM. Unlike most spider toxins that modulate NaV channels, Tp1a inhibited hNaV1.7 without significantly altering the voltage dependence of activation or inactivation. Tp1a proved to be analgesic by reversing spontaneous pain induced in mice by intraplantar injection in OD1, a scorpion toxin that potentiates hNaV1.7. The structure of Tp1a as determined using NMR spectroscopy revealed a classic inhibitor cystine knot (ICK) motif. The molecular surface of Tp1a presents a hydrophobic patch surrounded by positively charged residues, with subtle differences from other ICK spider toxins that might contribute to its different pharmacological profile. Tp1a may help guide the development of more selective and potent hNaV1.7 inhibitors for treatment of chronic pain.


    Organizational Affiliation

    Institute for Molecular Bioscience (F.C.C., Z.D., I.V., J.R.D., V.H., P.F.A., G.F.K., R.J.L.), School of Biomedical Sciences (K.J.R.), and School of Chemistry and Molecular Biosciences (A.E.), The University of Queensland, Brisbane, Queensland, Australia.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
entity
A
33Thrixopelma pruriensN/A
Find proteins for P0DL64 (Thrixopelma pruriens)
Go to UniProtKB:  P0DL64
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with acceptable covalent geometry 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2015-01-08 
  • Released Date: 2015-06-03 
  • Deposition Author(s): Rosengren, K.

Revision History 

  • Version 1.0: 2015-06-03
    Type: Initial release
  • Version 1.1: 2015-07-15
    Type: Database references