Characterization of molecular forms of acetyl- and butyrylcholinesterase in human acoustic neurinomas

Acoustic neurinomas were sequentially extracted with saline and saline-Trit on X-100 buffers. Detergent was required to detach the bulk of acetylcholin esterase (AChE), but butyrylcholinesterase (BuChE) was mostly released with saline buffer. Sedimentation analysis and hydrophobic chromatography revea led that neurinomas contain principally amphiphilic AChE tetramers, dimers and monomers, and hydrophilic BuChE tetramers. The AChE dimers and monomers remained amphiphilic after incubation with phosphatidylinositol-specific p hospholipase C (PIPLC), after or without prior treatment with alkaline hydr oxylamine, which shows that, in contrast to the meningioma AChE dimers and monomers, the neurinoma isoforms are devoid of glycolipid. Neurinoma AChE r eacted with the antibodies HR2 and AE1 raised against AChE from human brain or erythrocyte, whereas BuChE bound to a sheep antiserum. (C) 1999 Elsevie r Science Ireland Ltd. All rights reserved.