Evidence for and separation of globular hydrophobic and non-hydrophobic forms of acetylcholinesterase from bovine caudate nucleus.

Almost complete removal of the detergent from a purified 10.7S complex consisting of acetylcholinesterase and [3H]Triton X-100 bound to an affinity gel was achieved by extensive washing and subsequent elution of the enzyme. Applying this procedure of detergent removal, the majority of the enzyme could be stabilized by self-aggregation forming soluble 16S and 20S aggregates, which contained small amounts of bound residual Triton X-100 in the range of 0.4-1.6 mol Triton X-100 per mol acetylcholinesterase. Besides these aggregates, a nearly detergent-free 10.5S form was observed, lacking the hydrophobic region responsible for detergent binding and self-aggregation.