Acetylcholinesterase (AChE), a highly conserved enzyme in the animal k
ingdom, is distributed throughout a wide range of vertebrate tissues w
here 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 (G(4) AChE) consisting
of four identical catalytic subunits attached to cellular membranes b
y a hydrophobic noncatalytic subunit (P-subunit). This study focuses p
rimarily on current data involving the structure of the G(4) AChE P-su
bunit, the expression and regulation of G(4) AChE during development a
nd adulthood, and its role(s) in certain neurological disorders includ
ing Alzheimer's disease.