Photoaffinity labeling of D-2 dopamine binding subunits from rat striatum, anterior pituitary and olfactory bulb with a new probe, [3H]azidosulpride.
A novel photoaffinity probe [3H] azidosulpride has been developed for biochemical studies of D-2 dopamine receptors. This ligand binds to the receptors with high affinity (Kd = 3.1 +/- 0.2 nM) and, upon photoactivation, about 20% of the radioactivity bound to membranes becomes covalently incorporated. More than 90% of this irreversible binding is protectable by dopaminergic agents including D-2 selective compounds, whereas D-1 selective and non-dopaminergic compounds are ineffective. Analysis by sodium dodecylsulfate polyacrylamide gel electrophoresis reveals a single band at Mr = 85 kDa for labeled receptors in striatum, anterior pituitary or olfactory bulb, where pharmacologically distinct binding sites have been previously detected.
Redouane
K
K
Sokoloff
P
P
Schwartz
J C
JC
Hamdi
P
P
Mann
A
A
Wermuth
C G
CG
Roy
J
J
Morgat
J L
JL
D000345:Affinity Labels / Q000378:metabolism*; D000818:Animals; D001386:Azides / Q000138:chemical synthesis / Q000378:metabolism*; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism*; D007700:Kinetics; D009830:Olfactory Bulb / Q000378:metabolism*; D010777:Photochemistry; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D051381:Rats; D011954:Receptors, Dopamine / Q000378:metabolism*; D017448:Receptors, Dopamine D2; D013469:Sulpiride / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism; D014316:Tritium
D000345:Affinity Labels; D001386:Azides; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D014316:Tritium; D013469:Sulpiride; C046272:4-azidosulpiride