Molecular sizes of photolabeled GABA and benzodiazepine receptor proteins are identical.
[3H]Muscimol was irreversibly incorporated into rat cerebellar membranes upon irradiation with ultraviolet light. GABA agonists and antagonists inhibited this incorporation. The reversible muscimol-binding decreased after photoaffinity-labeling of the membranes with muscimol. These results indicated that this irreversible incorporation is to the GABA receptor. Photolabeled GABA receptor protein showed its Mr of 50000 +/- 1000 in SDS-polyacrylamide gel electrophoresis. This molecular size is identical to that of the benzodiazepine receptor which was photolabeled with 3H-flunitrazepam.
D000818:Animals; D001569:Benzodiazepines / Q000378:metabolism*; D002531:Cerebellum / Q000378:metabolism*; D005445:Flunitrazepam / Q000378:metabolism; D007700:Kinetics; D009118:Muscimol / Q000378:metabolism; D051381:Rats; D011956:Receptors, Cell Surface / Q000302:isolation & purification / Q000378:metabolism*; D011963:Receptors, GABA-A; D013574:Synaptosomes / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D011956:Receptors, Cell Surface; D011963:Receptors, GABA-A; D001569:Benzodiazepines; D009118:Muscimol; D005680:gamma-Aminobutyric Acid; D005445:Flunitrazepam