In muscle, it terminates signal transduction at the neuromuscular junction by rapid hydrolysis of the acetylcholine released into the synaptic cleft. In liver, its function is unclear: it could serve as a safeguard against any diffusion of acetylcholine from synapses into the circulation. In venom, its toxic role is unclear: it could result in less musculatory control by rapidly hydrolyzing acetylcholine, or that it works synergistically with alkaline phosphatase (ALP) in paralyzing prey through hypotension. acetylcholine + H2O = acetate + choline + H(+) Inhibited by active site inhibitors: edrophonium, trimethyl-(m-acetamidopheny1)-ammonium iodide, and trimethyl-(p-acetarnidopheny1)-ammonium iodide (PubMed:4197660, PubMed:9187246). Inhibited by both active and peripheral site inhibitors: decamethonium, and BW284c51 (PubMed:8662867, PubMed:9187246). Inhibited by peripheral site inhibitors: snake acetylcholinesterase fasciculin-2, propidium, gallamine, D-tubocurarine, and tacrine (PubMed:8662867, PubMed:9187246, PubMed:25411244). Also inhibited by antibodies Elec410 and Fab410 (PubMed:25411244). Isoform S is monomeric (PubMed:9545320, PubMed:8674549, PubMed:9187246). Isoform T can form oligomers, including collagen-tailed forms (PubMed:9545320). Liver and muscle contain both isoform T and isoform S. Venom gland predominantly contains isoform S. The N-terminus is blocked. A cleavage of the very basic 8-residue C-terminal fragment occurs upon secretion. Belongs to the type-B carboxylesterase/lipase family. It is uncertain whether Met-1 or Met-9 is the initiator.