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Photoaffinity labelling of dopamine D 2 receptors by [ 3 H]azidomethylspiperone
Author(s) -
Niznik Hyman B.,
Grigoriadis Dimitri E.,
Seeman Philip
Publication year - 1986
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(86)81086-9
Subject(s) - labelling , chemistry , receptor , dopamine , d 1 , dopamine receptor , photoaffinity labeling , biophysics , radiochemistry , biochemistry , neuroscience , biology
We have characterized the dopamine D 2 receptor photaffinity probe, [ 3 H]azido‐ N ‐methylspiperone ([ 3 H]AMS). In the absence of light, [ 3 H]AMS bound reversibly and with high affinity ( K d 70 pM) to sites in canine striatal membranes and was competitively inhibited by dopaminergic agonists and antagonists with an appropriate D 2 receptor specificity. Upon photolysis, [ 3 H]AMS covalently incorporated into a peptide of M r 92000 as assessed by fluorography following SDS‐polyacrylamide gel electrophoresis. Labelling of this peptide was specifically and stereoselectively blocked by D 2 antagonists and agonists. Minor specifically labelled peptides of M r 70000‐55000 were observed under some conditions and were the result of proteolytic degradation of the peptide at M r , 92000.