简介:RecombinanthumanGABAAreceptorswereinvestigatedinvitrobycoexpressionofcDNAscodingforα1,β2andγ2subunitsinthebaculovirus/Sf-9insectcellsystem,Asingleaminoacidexchangeα1(asparaticacid151toasparaginorα1(threonine149toglutamine)intheN-terminal,extracellularpartoftheα1subunitinducedabout10folddecreaseinanantagonistpitrazepineaffinity.OtherGABAAreceptorligandshadlittledifferenceintheiraffinity.Itwaslikelythat151and149aminoacidresidueswereessentialforthebindingaffinityandefficacyofpitrazepinetoGABAAreceptorcombinationscontainiαααααααααnganα1subunit.