5T3M

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

5T3M の概要

• エントリーDOI: 10.2210/pdb5t3m/pdb
• NMR情報: BMRB: 30160
• 分子名称: Mu-theraphotoxin-Hs2a (1 entity in total)
• 機能のキーワード: toxin
• 由来する生物種: Haplopelma schmidti (Chinese bird spider)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 3999.78

構造登録者

Rahnama, S.,Sharma, G.,Mobli, M. (登録日: 2016-08-25, 公開日: 2017-09-06, 最終更新日: 2024-10-30)

主引用文献

Rahnama, S.,Deuis, J.R.,Cardoso, F.C.,Ramanujam, V.,Lewis, R.J.,Rash, L.D.,King, G.F.,Vetter, I.,Mobli, M.
The structure, dynamics and selectivity profile of a NaV1.7 potency-optimised huwentoxin-IV variant.
PLoS ONE, 12:e0173551-e0173551, 2017

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. 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.

PubMed: 28301520
DOI: 10.1371/journal.pone.0173551

実験手法

SOLUTION NMR