Tetrameric (G4) acetylcholinesterase: structure, localization, and physiological regulation.

Acetylcholinesterase (AChE), a highly conserved enzyme in the animal kingdom, is distributed throughout a wide range of vertebrate tissues where it is expressed as multiple molecular forms comprising different arrangements of catalytic and structural subunits. The major AChE form in the CNS is an amphiphilic globular tetramer (G4 AChE) consisting of four identical catalytic subunits attached to cellular membranes by a hydrophobic noncatalytic subunit (P-subunit). This study focuses primarily on current data involving the structure of the G4 AChE P-subunit, the expression and regulation of G4 AChE during development and adulthood, and its role(s) in certain neurological disorders including Alzheimer's disease.