BIOORGANIC STUDIES OF TRANSMITTER RECEPTORS WITH PHILANTHOTOXIN ANALOGS

Philanthotoxin-433 (PhTX-433), isolated from the venom sac of the wasp Philanthus triangulum, is a noncompetitive antagonist of glutamate an d nicotinic acetylcholine receptors. Extensive structure-activity stud ies performed with approximately 100 synthetic analogs have provided s everal highly active analogs carrying photolabile/radioactive groups a t various sites of this linear molecule. Preliminary photoaffinity lab eling studies of a nicotinic acetylcholine receptor have led to a mode l showing the mode of binding of PhTX to this receptor.