Photoaffinity labeling and quaternary structure of the acetylcholine receptor from Torpedo californica.
AUTOR(ES)
Hucho, F
RESUMO
Membrane fragments from electric tissue of Torpedo californica containing nicotinic acetylcholine receptor are composed of four different polypeptide chains with molecular weights of 40,000 (alpha), 48,000 (beta), 62,000 (gamma), and 66,000 (delta). The alpha and beta chains are still present in all and gamma and delta in some of the receptor preparations after Triton X-100 extraction and purification by affinity chromatography. All components of the receptor react covalently with the photoaffinity label 4-azido-2-nitrobenzyltrimethylammonium fluoroborate, the delta chain incorporating less of the reagent as compared to the alpha and beta chains. Agonists and antagonists containing a quaternary ammonium group protect all chains against the label; the principal neurotoxin from Naja naja siamensis protects the alpha chain only. We conclude that the alpha chain binds the neurotoxin from Naja naja, the alpha and beta chains are involved in the binding of ligands with quaternary ammonium groups, and the function of the gamma and delta chains remains to be determined.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=430700Documentos Relacionados
- Photoaffinity labeling of Torpedo acetylcholine receptor at multiple sites.
- Correlation of polypeptide composition with functional events in acetylcholine receptor-enriched membranes from Torpedo californica.
- Determination of the primary amino acid sequence specifying the alpha-bungarotoxin binding site on the alpha subunit of the acetylcholine receptor from Torpedo californica.
- Nucleotide sequence of an intermediate filament cDNA from Torpedo californica.
- Reconstitution of functional membrane-bound acetylcholine receptor from isolated Torpedo californica receptor protein and electroplax lipids.