Scorpion toxins for the reversal of BoNT-induced paralysis

Bioorg Med Chem Lett. 2013 Dec 15;23(24):6743-6. doi: 10.1016/j.bmcl.2013.10.029. Epub 2013 Oct 25.

Abstract

The botulinum neurotoxins, characterized by their neuromuscular paralytic effects, are the most toxic proteins known to man. Due to their extreme potency, ease of production, and duration of activity, the BoNT proteins have been classified by the Centers for Disease Control as high threat agents for bioterrorism. In an attempt to discover effective BoNT therapeutics, we have pursued a strategy in which we leverage the blockade of K(+) channels that ultimately results in the reversal of neuromuscular paralysis. Towards this end, we utilized peptides derived from scorpion venom that are highly potent K(+) channel blockers. Herein, we report the synthesis of charybdotoxin, a 37 amino acid peptide, and detail its activity, along with iberiotoxin and margatoxin, in a mouse phrenic nerve hemidiaphragm assay in the absence and the presence of BoNT/A.

Keywords: Aminopyridine; Bioterrorism; Botulinum neurotoxin; Phrenic nerve hemidiaphragm; Scorpion toxin.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Botulinum Toxins*
  • Charybdotoxin / chemistry*
  • Charybdotoxin / pharmacology
  • Charybdotoxin / therapeutic use
  • Mice
  • Molecular Sequence Data
  • Muscle Contraction / drug effects
  • Paralysis / chemically induced*
  • Paralysis / drug therapy*
  • Peptides / chemistry
  • Peptides / pharmacology
  • Phrenic Nerve / drug effects*
  • Potassium Channel Blockers / chemistry*
  • Potassium Channel Blockers / pharmacology
  • Potassium Channel Blockers / therapeutic use
  • Resins, Synthetic / chemistry
  • Scorpion Venoms* / chemistry
  • Scorpion Venoms* / pharmacology
  • Scorpion Venoms* / therapeutic use

Substances

  • Peptides
  • Potassium Channel Blockers
  • Resins, Synthetic
  • Scorpion Venoms
  • Charybdotoxin
  • margatoxin
  • iberiotoxin
  • Botulinum Toxins