Dopamine D2 receptors photolabeled by iodo-azido-clebopride.
Iodo-azido-clebopride, a photoaffinity compound for dopamine D2 receptors, had high affinity for canine brain striatal dopamine D2 receptors with a dissociation constant (Kd) of 14 nM. Irradiation of striatal homogenate with iodo-azido-clebopride irreversibly inactivated 50% of dopamine D2 receptors at 20 nM (as indicated by subsequent [3H]spiperone binding). Dopamine agonists and antagonists prevented this photo-inactivation with the appropriate rank-order of potency. Striatal dopamine D1, serotonin (S2), alpha 1- and beta-adrenoceptors were not significantly inactivated following irradiation with iodo-azido-clebopride. Thus, iodo-azido-clebopride is a selective photoaffinity probe for dopamine D2 receptors, the radiolabelled form of which may aid in the molecular characterization of these proteins.
Niznik
H B
HB
Dumbrille-Ross
A
A
Guan
J H
JH
Neumeyer
J L
JL
Seeman
P
P
D000345:Affinity Labels; D000818:Animals; D001667:Binding, Competitive; D003342:Corpus Striatum / Q000032:analysis / Q000378:metabolism; D004285:Dogs; D004298:Dopamine / Q000502:physiology; D018492:Dopamine Antagonists; D010782:Photolysis; D011954:Receptors, Dopamine / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism; D017448:Receptors, Dopamine D2; D012984:Software
D000345:Affinity Labels; D018492:Dopamine Antagonists; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D004298:Dopamine