5TLR

Solution NMR structure of gHwTx-IV

Summary for 5TLR

• Entry DOI: 10.2210/pdb5tlr/pdb
• NMR Information: BMRB: 30190
• Descriptor: Mu-theraphotoxin-Hs2a (1 entity in total)
• Functional Keywords: spider toxin, disulfide-rich, sodium channel inhibitor, toxin
• Biological source: Haplopelma schmidti (Chinese bird spider)
• Total number of polymer chains: 1
• Total formula weight: 4036.82

Authors

Agwa, A.J.,Schroeder, C.I. (deposition date: 2016-10-11, release date: 2017-02-22, Last modification date: 2024-11-13)

Primary citation

Agwa, A.J.,Lawrence, N.,Deplazes, E.,Cheneval, O.,Chen, R.M.,Craik, D.J.,Schroeder, C.I.,Henriques, S.T.
Spider peptide toxin HwTx-IV engineered to bind to lipid membranes has an increased inhibitory potency at human voltage-gated sodium channel hNaV1.7.
Biochim. Biophys. Acta, 1859:835-844, 2017

PubMed Abstract: The human voltage-gated sodium channel sub-type 1.7 (hNa1.7) is emerging as an attractive target for the development of potent and sub-type selective novel analgesics with increased potency and fewer side effects than existing therapeutics. HwTx-IV, a spider derived peptide toxin, inhibits hNa1.7 with high potency and is therefore of great interest as an analgesic lead. In the current study we examined whether engineering a HwTx-IV analogue with increased ability to bind to lipid membranes would improve its inhibitory potency at hNa1.7. This hypothesis was explored by comparing HwTx-IV and two analogues [E1PyrE]HwTx-IV (mHwTx-IV) and [E1G,E4G,F6W,Y30W]HwTx-IV (gHwTx-IV) on their membrane-binding affinity and hNa1.7 inhibitory potency using a range of biophysical techniques including computational analysis, NMR spectroscopy, surface plasmon resonance, and fluorescence spectroscopy. HwTx-IV and mHwTx-IV exhibited weak affinity for lipid membranes, whereas gHwTx-IV showed improved affinity for the model membranes studied. In addition, activity assays using SH-SY5Y neuroblastoma cells expressing hNa1.7 showed that gHwTx-IV has increased activity at hNa1.7 compared to HwTx-IV. Based on these results we hypothesize that an increase in the affinity of HwTx-IV for lipid membranes is accompanied by improved inhibitory potency at hNa1.7 and that increasing the affinity of gating modifier toxins to lipid bilayers is a strategy that may be useful for improving their potency at hNa1.7.

PubMed: 28115115
DOI: 10.1016/j.bbamem.2017.01.020

Experimental method

SOLUTION NMR