Homomeric and native α7 acetylcholine receptors exhibit remarkably similar but non‐identical pharmacological properties, suggesting that the native receptor is a heteromeric protein complex

[摘要]

Sucrose gradient analysis of chick acetylcholine receptor (AChR) α7 subunits expressed in oocytes indicates that they form pharmacologically active homomers of the same size as native α7 AChRs, a size compatible with a complex of five α7 subunits. By immunoisolating the [³⁵S]methionine-labeled α7 subunits we also demonstrate that they do not appear to assemble with endogenous Xenopus AChR subunits. Pharmacological characterization of detergent-solubilized brain α7 AChRs and α7 homomers reveals that they have similar but nonidentical properties. The pharmacological difference is most accentuated for cytisine (~50-fold). Thus, at least in E18 chicken brain, most or all of the native α7 AChRs do not appear to be homomeric.

[学科分类] 生物化学/生物物理

[关键词] Acetylcholine receptor;α-Bungarotoxin;Pharmacology;Xenopus oocyte;Homomeric receptor;α7 subunit;αBgt;α-bungarotoxin;ACh;acetylcholine;AChR;acetylcholine receptor;Carb;carbamylcholine;Deca;decamethonium;EDTA;[ethylenedinitrilo]tetraacetic acid;EGTA;[ethyl-ene-bis(oxyethylenenitrilo)]tetraacetic acid;Hex;hexamethonium;mAb;monoclonal antibody;PBS;phosphate-buffered saline;RIA;radioimmunoassay;TEA;tetraethylammonium;TMA;tetramethylammonium