STUDY OF THE MUSCARINIC RECEPTOR BY GEL-ELECTROPHORESIS

Muscarinic receptors from the brain of rat, guinea‐pig and frog have been labelled with tritiated propylbenzilylcholine mustard ([3H]‐PrBCM). After solubilisation and sodium dodecyl sulphate (SDS)‐polyacrylamide gel electrophoresis a single radiolabeled peak was seen which was completely suppressed when labelling was carried out in the presence of 10−6 m atropine. The results suggest the presence of a single polypeptide chain with a molecular weight of ∼80,000. In the case of intestinal smooth muscle multiple labelled peaks were found. Precautions against proteolysis led to the identification of a major peak with a molecular weight in the region of 80,000. 1979 British Pharmacological Society