Engineered site-directed labeling of nicotinic acetylcholine receptors using reactive epibatidine derivatives: appraisal of epibatidine-docking models in neuronal and muscular receptors

J Mol Neurosci. 2006;30(1-2):35-6. doi: 10.1385/JMN:30:1:35.


We developed an engineered site-directed labeling method (Foucaud et al., 2001) to investigate ligand receptor interactions on the acetylcholine (ACh)- binding site of nicotinic acetylcholine receptors (nAChRs). The method uses cysteine receptor mutants, together with cysteine-reactive ligand analogs, to generate a site-directed covalent reaction within the binding site. We selected epibatidine (EPB) as a prototypical ligand, acting at all types of nAChRs with sufficient affinity to allow this study. Accordingly, we synthesized three cysteine-reactive derivatives, all modified at the C-3 of the pyridine ring of the alkaloid with NCS; -NHCOCH2Cl, and -CH2Cl groups, respectively (Fig. 1). The binding properties have been established on rat brain, alpha7-5HT3 chimera, and Torpedo membranes, respectively, whereas the functional properties were tested on alpha4beta2 and alpha7 receptor expressed in oocytes and Cys-less muscular receptor expressed in HEK cells (Sakr et al., 2005).

MeSH terms

  • Animals
  • Bridged Bicyclo Compounds, Heterocyclic / chemistry
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacokinetics*
  • Cell Line
  • Humans
  • Models, Molecular
  • Mutant Proteins / chemistry
  • Mutant Proteins / metabolism
  • Nicotinic Agonists / chemistry
  • Nicotinic Agonists / pharmacokinetics*
  • Pyridines / chemistry
  • Pyridines / pharmacokinetics*
  • Receptors, Nicotinic / chemistry*
  • Receptors, Nicotinic / physiology*
  • Torpedo


  • Bridged Bicyclo Compounds, Heterocyclic
  • Mutant Proteins
  • Nicotinic Agonists
  • Pyridines
  • Receptors, Nicotinic
  • epibatidine