ω-Conotoxin GVIA mimetics that bind and inhibit neuronal Ca(v)2.2 ion channels

Mar Drugs. 2012 Oct;10(10):2349-68. doi: 10.3390/md10102349. Epub 2012 Oct 22.

Abstract

The neuronal voltage-gated N-type calcium channel (Ca(v)2.2) is a validated target for the treatment of neuropathic pain. A small library of anthranilamide-derived ω-Conotoxin GVIA mimetics bearing the diphenylmethylpiperazine moiety were prepared and tested using three experimental measures of calcium channel blockade. These consisted of a ¹²⁵I-ω-conotoxin GVIA displacement assay, a fluorescence-based calcium response assay with SH-SY5Y neuroblastoma cells, and a whole-cell patch clamp electrophysiology assay with HEK293 cells stably expressing human Ca(v)2.2 channels. A subset of compounds were active in all three assays. This is the first time that compounds designed to be mimics of ω-conotoxin GVIA and found to be active in the ¹²⁵I-ω-conotoxin GVIA displacement assay have also been shown to block functional ion channels in a dose-dependent manner.

Keywords: Ca2+ fluorescence assay; Cav2.2; conotoxin; patch clamp electrophysiology; peptidomimetics; radioligand binding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium Channels, N-Type / genetics
  • Calcium Channels, N-Type / metabolism*
  • Cell Line, Tumor
  • Electrophysiological Phenomena
  • Humans
  • Molecular Structure
  • Patch-Clamp Techniques
  • Structure-Activity Relationship
  • omega-Conotoxin GVIA / chemistry*
  • omega-Conotoxin GVIA / pharmacology*

Substances

  • CACNA1B protein, human
  • Calcium Channels, N-Type
  • omega-Conotoxin GVIA