Quaternary Structure of Tetrameric Acetylcholinesterase

Most vertebrates contain a single gene encoding for AChE, and alternative splicing gives rise to two catalytic subunits, H and T. H subunits form GPI-anchored dimers, whereas T subunits can occur as monomers, dimers and tetramers, which are dimers of disulfide-linked dimers. T subunits also associate with structural subunits (P and Q) to form membrane-anchored tetramers and asymmetric forms, in which one to three tetramers are attached to a collagen-like tail (1).