First use of a beta-carboline as photoaffinity label for the benzodiazepine receptor.
Photolabelling of benzodiazepine receptors isolated from rat cortex with a new beta-carboline-type photoaffinity label, ethyl 6-azido-beta-carboline-3-carboxylase, at 254 nm produced a 42% decrease in the maximal number of propyl beta-carboline-3-carboxylate binding sites but practically no decrease in the number of flunitrazepam binding sites. Moreover, the binding affinity of ethyl beta-carboline-3-carboxylase was diminished 11-fold by photolabelling while that of diazepam was diminished less than 2-fold. These results provide additional evidence that beta-carbolines and benzodiazepines bind to discrete sites on the benzodiazepine receptor.
Dellouve-Courillon
C
C
Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
Lambolez
B
B
Potier
P
P
Dodd
R H
RH
D000345:Affinity Labels; D000818:Animals; D002243:Carbolines / Q000378:metabolism; D005442:Flumazenil / Q000378:metabolism; D005445:Flunitrazepam / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D010777:Photochemistry; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects*
D000345:Affinity Labels; D002243:Carbolines; D011963:Receptors, GABA-A; D005442:Flumazenil; D005445:Flunitrazepam; C028585:propyl beta-carboline-3-carboxylate