8-Hydroxyquinoline and hydroxamic acid inhibitors of botulinum neurotoxin BoNT/A

Curr Top Med Chem. 2014;14(18):2094-102. doi: 10.2174/1568026614666141022095114.

Abstract

We describe here the state of the art of certain aspects concerning potential small molecule therapy directed toward botulism, by inhibition of the zinc-protease containing light chain (LC) of botulinum neurotoxin BoNT/A from the anaerobic bacillus Clostridium botulinum. Botulinum neurotoxins (BoNTs) are comprised of eight serologically-distinct proteins (A - H), several of which are further divided, such as BoNT/A which has five subtypes. The BoNTs are the most toxic substances known to mankind, causing a form of flaccid paralysis that can be rapid and is often lethal. BoNT/A is comprised of a ~100 kDa heavy chain (HC) attached via a single disulfide Cys-Cys bond to a ~50 kDa LC. The HC mediates transport to and uptake by presynaptic glutamatergic neurons, where the LC cleaves the protein SNAP-25 and thus prevents vesicular trafficking and release of acetylcholine. The Zn-endoprotease activity of the LC of BoNT/A is a target for the development of small molecule inhibitors of BoNT/A-mediated toxicity. A variety of BoNT/A LC inhibitors have been described to date and we focus here primarily on the Zn-binding 8-hydroxyquinoline structural type as well as some of the previously-described hydroxamic acids.

Publication types

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

MeSH terms

  • Animals
  • Antidotes / chemistry
  • Antidotes / pharmacology*
  • Botulinum Toxins, Type A / antagonists & inhibitors*
  • Botulinum Toxins, Type A / chemistry
  • Botulinum Toxins, Type A / toxicity
  • Botulism / drug therapy
  • Botulism / pathology
  • Chelating Agents / chemistry
  • Chelating Agents / pharmacology*
  • Clostridium botulinum / pathogenicity
  • Clostridium botulinum / physiology
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology*
  • Humans
  • Hydroxamic Acids / chemistry
  • Hydroxamic Acids / pharmacology*
  • Models, Molecular
  • Motor Neurons / drug effects
  • Motor Neurons / pathology
  • Oxyquinoline / chemistry
  • Oxyquinoline / pharmacology*
  • Paralysis / drug therapy
  • Paralysis / pathology
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / pharmacology
  • Synaptic Transmission / drug effects
  • Zinc / chemistry
  • Zinc / metabolism

Substances

  • Antidotes
  • Chelating Agents
  • Enzyme Inhibitors
  • Hydroxamic Acids
  • Small Molecule Libraries
  • Oxyquinoline
  • Botulinum Toxins, Type A
  • Zinc