Immunoprecipitation of an affinity-alkylated fragment of the muscarinic acetylcholine receptor with an anti-ligand monoclonal antibody.
A monoclonal antibody raised against the muscarinic acetylcholine affinity-alkylating antagonist propylbenzilylcholine mustard was tested for its ability to recognize affinity-alkylated muscarinic receptors. We demonstrate here that although the antibody will not recognize the mustard when it is covalently linked to the native muscarinic receptor, trypsinization of affinity-labeled membranes releases a proteolytic labeled fragment that can be specifically immunoprecipitated by the antibody. Electrophoretic analysis of the immunoprecipitate indicates that the ligand was associated with a polypeptide of molecular weight 5,000. The recognition of this fragment by the antibody provides a means to immunopurify a portion of the muscarinic receptor that is at or near the ligand binding site.
D000345:Affinity Labels / Q000378:metabolism*; D000477:Alkylating Agents / Q000378:metabolism*; D000818:Animals; D000911:Antibodies, Monoclonal; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay; D008970:Molecular Weight; D010446:Peptide Fragments / Q000378:metabolism; D011438:Propylbenzilylcholine Mustard / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000378:metabolism*; D014357:Trypsin / Q000378:metabolism
D000345:Affinity Labels; D000477:Alkylating Agents; D000911:Antibodies, Monoclonal; D010446:Peptide Fragments; D011950:Receptors, Cholinergic; D011438:Propylbenzilylcholine Mustard; D014357:Trypsin