2019 - Development of Photocrosslinking Probes Based on Huwentoxin-IV to Map the Site of Interaction on Nav1.7
SyncroPatch 768PE (a predecessor model of the SyncroPatch 384/768i) Publication in Cell Chemical Biology (2019)
Authors:
Tzakoniati F., Xu H., Li T., Garcia N., Kugel C., Payandeh J., Koth C.M., Tate E.W.
Journal:
Cell Chemical Biology (2019) In Press, corrected proof doi.org/10.1016/j.chembiol.2019.10.011
Highlights:
- Development of six potent diazirine-containing photoprobes based on Huwentoxin-IV
- Photoprobes specifically photolabel purified bacterial-Nav1.7 VSD2 chimeric channels
- Proteomic mass spectrometry identifies binding site on S1-S2 loop and S3 helix
- Proposed model of HwTx-IV binding reveals importance of K27 and R29
Summary:
Voltage-gated sodium (Nav) channels respond to changes in the membrane potential of excitable cells through the concerted action of four voltage-sensor domains (VSDs). Subtype Nav1.7 plays an important role in the propagation of signals in pain-sensing neurons and is a target for the clinical development of novel analgesics. Certain inhibitory cystine knot (ICK) peptides produced by venomous animals potently modulate Nav1.7; however, the molecular mechanisms underlying their selective binding and activity remain elusive. This study reports on the design of a library of photoprobes based on the potent spider toxin Huwentoxin-IV and the determination of the toxin binding interface on VSD2 of Nav1.7 through a photocrosslinking and tandem mass spectrometry approach. Our Huwentoxin-IV probes selectively crosslink to extracellular loop S1-S2 and helix S3 of VSD2 in a chimeric channel system. Our results provide a strategy that will enable mapping of sites of interaction of other ICK peptides on Nav channels.