Biomaterial Database

Affinity labeling of muscarinic receptors in rat cerebral cortex with a photolabile antagonist. 1982

G Amitai, and S Avissar, and D Balderman, and M Sokolovsky

Highly potent photoaffinity probes for muscarinic binding sites were prepared by the incorporation of an azido group into the benzilic acid moiety in two compound, 3-quinuclidinyl benzilate (3QNB) and N-methyl-4-piperidyl benzilate (4NMPB). Inactivation of muscarinic sites in rat cortex depends on the formation of a reversible complex with the azides prior to their photolytic conversion to the highly reactive nitrenes. During photolysis, radiolabeled azido-4NMPB interacted specifically and with high affinity (Kd = 1.06 nM) with the muscarinic receptors, and the ligand could be covalently incorporated into a macromolecule of about 86,000 Mr, presumably the muscarinic receptor. The incorporation was almost stoichiometric when compared to determination of receptor density by reversible ligands. Atropine (10 microM) afforded specific protection (greater than 83%) of the receptor against inactivation by azido-[3H]4NMPB. This compound and the other ligands described here (i.e., amino-4NMPB, amino-3QNB, and azido-3QNB) represent powerful potential probes for the biochemical isolation and characterization of muscarinic receptors.

UI	MeSH Term	Description	Entries
D010276	Parasympatholytics	Agents that inhibit the actions of the parasympathetic nervous system. The major group of drugs used therapeutically for this purpose is the MUSCARINIC ANTAGONISTS.	Antispasmodic,Antispasmodic Agent,Antispasmodic Drug,Antispasmodics,Parasympathetic-Blocking Agent,Parasympathetic-Blocking Agents,Parasympatholytic,Parasympatholytic Agent,Parasympatholytic Drug,Spasmolytic,Spasmolytics,Antispasmodic Agents,Antispasmodic Drugs,Antispasmodic Effect,Antispasmodic Effects,Parasympatholytic Agents,Parasympatholytic Drugs,Parasympatholytic Effect,Parasympatholytic Effects,Agent, Antispasmodic,Agent, Parasympathetic-Blocking,Agent, Parasympatholytic,Agents, Antispasmodic,Agents, Parasympathetic-Blocking,Agents, Parasympatholytic,Drug, Antispasmodic,Drug, Parasympatholytic,Drugs, Antispasmodic,Drugs, Parasympatholytic,Effect, Antispasmodic,Effect, Parasympatholytic,Effects, Antispasmodic,Effects, Parasympatholytic,Parasympathetic Blocking Agent,Parasympathetic Blocking Agents
D010777	Photochemistry	A branch of physical chemistry which studies chemical reactions, isomerization and physical behavior that may occur under the influence of visible and/or ultraviolet light.	Photochemistries
D010880	Piperidines	A family of hexahydropyridines.
D011812	Quinuclidines	A class of organic compounds which contain two rings that share a pair of bridgehead carbon atoms and contains an amine group.	Quinuclidine
D011813	Quinuclidinyl Benzilate	A high-affinity muscarinic antagonist commonly used as a tool in animal and tissue studies.	Benzilate, Quinuclidinyl
D011950	Receptors, Cholinergic	Cell surface proteins that bind acetylcholine with high affinity and trigger intracellular changes influencing the behavior of cells. Cholinergic receptors are divided into two major classes, muscarinic and nicotinic, based originally on their affinity for nicotine and muscarine. Each group is further subdivided based on pharmacology, location, mode of action, and/or molecular biology.	ACh Receptor,Acetylcholine Receptor,Acetylcholine Receptors,Cholinergic Receptor,Cholinergic Receptors,Cholinoceptive Sites,Cholinoceptor,Cholinoceptors,Receptors, Acetylcholine,ACh Receptors,Receptors, ACh,Receptor, ACh,Receptor, Acetylcholine,Receptor, Cholinergic,Sites, Cholinoceptive
D011976	Receptors, Muscarinic	One of the two major classes of cholinergic receptors. Muscarinic receptors were originally defined by their preference for MUSCARINE over NICOTINE. There are several subtypes (usually M1, M2, M3....) that are characterized by their cellular actions, pharmacology, and molecular biology.	Muscarinic Acetylcholine Receptors,Muscarinic Receptors,Muscarinic Acetylcholine Receptor,Muscarinic Receptor,Acetylcholine Receptor, Muscarinic,Acetylcholine Receptors, Muscarinic,Receptor, Muscarinic,Receptor, Muscarinic Acetylcholine,Receptors, Muscarinic Acetylcholine
D001923	Brain Chemistry	Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.	Chemistry, Brain,Brain Chemistries,Chemistries, Brain
D000345	Affinity Labels	Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.	Affinity Labeling Reagents,Labeling Reagents, Affinity,Labels, Affinity,Reagents, Affinity Labeling
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia