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A photoaffinity ligand of the acetylcholine‐binding site predominantly labels the region 179–207 of the α‐subunit on native acetylcholine receptor from Torpedo marmorata
Author(s) -
Dennis Michael,
Giraudat Jérôme,
Kotzyba-Hibert Florence,
Goeldner Maurice,
Hirth Christian,
Chang Jui-Yoa,
Changeux Jean-Pierre
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)81497-1
Subject(s) - torpedo , cyanogen bromide , acetylcholine receptor , chemistry , protein subunit , binding site , ligand (biochemistry) , acetylcholine , affinity labeling , biochemistry , photoaffinity labeling , stereochemistry , affinity label , receptor , peptide sequence , biology , gene , endocrinology
Regions of the Torpedo marmorata acetylcholine receptor (AChR) α‐subunit involved in the binding of acetylcholine were probed with two different covalent ligands. The sulfhydryl‐directed affinity reagent 4‐( N ‐maleimido)phenyltrimethylammonium iodide labeled a single α‐subunit cyanogen bromide fragment on the reduced AChR which was identified as α 179–207. The novel photoaffinity ligand p ‐( N,N ‐dimethylamino)‐benzenediazonium fluoroborate, on the other hand, labeled three distinct α‐chain cyanogen bromide fragments on the unmodified AChR in a carbamylcholine‐protectable manner. The major radiolabeled species was purified and identified by sequence analysis as α 179–207. The acetylcholine‐binding site on the native AChR may thus involve several distinct portions of the α‐chain, with the region α 179–207 making a major contribution to the site.