Enzymatic Ligation of a Pore Blocker Toxin and a Gating Modifier Toxin: Creating Double-Knotted Peptides with Improved Sodium Channel NaV1.7 Inhibition

Bioconjug Chem. 2020 Jan 15;31(1):64-73. doi: 10.1021/acs.bioconjchem.9b00744. Epub 2019 Dec 16.

Abstract

Disulfide-rich animal venom peptides targeting either the voltage-sensing domain or the pore domain of voltage-gated sodium channel 1.7 (NaV1.7) have been widely studied as drug leads and pharmacological probes for the treatment of chronic pain. However, despite intensive research efforts, the full potential of NaV1.7 as a therapeutic target is yet to be realized. In this study, using evolved sortase A, we enzymatically ligated two known NaV1.7 inhibitors-PaurTx3, a spider-derived peptide toxin that modifies the gating mechanism of the channel through interaction with the voltage-sensing domain, and KIIIA, a small cone snail-derived peptide inhibitor of the pore domain-with the aim of creating a bivalent inhibitor which could interact simultaneously with two noncompeting binding sites. Using electrophysiology, we determined the activity at NaV1.7, and to maximize potency, we systematically evaluated the optimal linker length, which was nine amino acids. Our optimized synthetic bivalent peptide showed improved channel affinity and potency at NaV1.7 compared to either PaurTx3 or KIIIA individually. This work shows that novel and improved NaV1.7 inhibitors can be designed by combining a pore blocker toxin and a gating modifier toxin to confer desired pharmacological properties from both the voltage sensing domain and the pore domain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • HEK293 Cells
  • Humans
  • Models, Molecular
  • Mollusk Venoms / chemistry
  • Mollusk Venoms / pharmacology
  • NAV1.7 Voltage-Gated Sodium Channel / metabolism*
  • Peptides / chemistry*
  • Peptides / pharmacology*
  • Snails / chemistry
  • Spider Venoms / chemistry
  • Spider Venoms / pharmacology
  • Spiders / chemistry
  • Voltage-Gated Sodium Channel Blockers / chemistry*
  • Voltage-Gated Sodium Channel Blockers / pharmacology*

Substances

  • Mollusk Venoms
  • NAV1.7 Voltage-Gated Sodium Channel
  • Peptides
  • SCN9A protein, human
  • Spider Venoms
  • Voltage-Gated Sodium Channel Blockers