Amino acid residues of both the extracellular and transmembrane domains influence binding of the antiparasitic agent milbemycin to Haemonchus contortus AVR-14B glutamate-gated chloride channels

► Action of antiparasitic milbemycin on mutant glutamate-gated chloride channels. ► Amino acids in extracellular and transmembrane domains influence milbemycin action. ► Milbemycin has two binding sites in the channel.