Terminates signal transduction at the neuromuscular junction by rapid hydrolysis of the acetylcholine released into the synaptic cleft. acetylcholine + H2O = acetate + choline + H(+) Homotetramer; composed of disulfide-linked homodimers. Catalytic forms H (GPI-anchor dimer) and T (asymmetric collagen-tailed), which differ in their C-terminus, account for all types of known ACHE forms (Probable). Interacts with PRIMA1. The interaction with PRIMA1 is required to anchor it to the basal lamina of cells and organize into tetramers (By similarity). Has been found in central nervous system and muscle (PubMed:8417155). Found in embryonic liver and spleen but not in adult liver (PubMed:8417155). May be not functional. Belongs to the type-B carboxylesterase/lipase family.