Immunogen sequence: RRSTSTTGKP SQATGPSANW AKAEQLTTCS SYPSSEDEDK PATDPVLQVV YKSQGKESPG EEFSAEETEE TFVKAETEKS DYDTPNYLLS PAAAHR. The muscarinic cholinergic receptors belong to a larger family of G protein-coupled receptors. The functional diversity of thes