Photoaffinity labeling of avermectin binding sites from Caenorhabditis elegans and Drosophila melanogaster Academic Article uri icon


MeSH Major

  • Caenorhabditis
  • Drosophila melanogaster
  • Ivermectin
  • Membrane Proteins
  • Proteins


  • An azido-avermectin analog [4'' alpha-(4-azidosalicylamido-epsilon-caproylamido-beta-alan ylamido)-4''-deoxyavermectin B1a; azido-AVM] was synthesized and used to photoaffinity label avermectin binding sites present in the membranes of Caenorhabditis elegans and Drosophila melanogaster. Azido-AVM was biologically active and behaved like a competitive inhibitor of [3H]ivermectin binding to C. elegans membranes (Ki = 0.2 nM). Radiolabeled azido-AVM bound specifically and with high affinity to C. elegans membranes (Kd = 0.14 nM) and, upon photoactivation, became covalently linked to three C. elegans polypeptides of 53, 47, and 8 kDa. Photoaffinity labeling of a membrane preparation from D. melanogaster heads resulted in labeling of a single major polypeptide of approximately 47 kDa. The proteins that were covalently tagged in these experiments are believed to be associated with avermectin-sensitive chloride channels present in the neuromuscular systems of C. elegans and D. melanogaster. Azido-AVM did not bind to rat brain membranes and therefore was selective for the nematode and insect receptors.

publication date

  • January 1992



  • Academic Article



  • eng

PubMed Central ID

  • PMC525654

Digital Object Identifier (DOI)

  • 10.1073/pnas.89.9.4168

PubMed ID

  • 1315055

Additional Document Info

start page

  • 4168

end page

  • 72


  • 89


  • 9