C. Floresflores et al., CONVERSION OF ACETYLCHOLINESTERASE HYDROPHILIC TETRAMERS INTO AMPHIPHILIC DIMERS AND MONOMERS, Biochemical and biophysical research communications, 219(1), 1996, pp. 53-58
Exposure of purified hydrophilic tetramers of acetylcholinesterase (AC
hE) from fetal bovine serum to various guanidinium chloride (Gdn) conc
entrations led to inactive tetramers (2 M Gdn) and dimers (6 M Gdn). T
he native tetramers were almost fully monomerized by reduction, a mino
r fraction of the released monomers remaining active. Sedimentation an
alysis and hydrophobic chromatography showed that the modified tetrame
rs, dimers and monomers had amphiphilic properties. Intrinsic fluoresc
ence spectra and binding of the amphiphilic probe, 1-anilino-8-naphtha
lene sulfonate (ANS), revealed that AChE subunits in the modified tetr
amers were in a 'molten globule' structure, the dimers in a denatured
state, and the inactive monomers in a 'native-like' structure. These d
ata show that AChE subunits possess a flexible conformation, which may
be important for generating a full set of molecular forms. In additio
n, the behavior of the active monomers with amphiphiles may explain th
e interactions of type II AChE forms with membranes. (C) 1996 Academic
Press, Inc.