MOLECULAR-FORMS OF ACETYLCHOLINESTERASE AND BUTYRYLCHOLINESTERASE IN HUMAN GLIOMA

Specimens of astrocytoma, oligodendroglioma and medulloblastoma were s equentially extracted with saline and saline-Triton X-100 buffers. Ace tyl- (AChE) and butyrylcholinesterase (BuChE) activities were assayed in the soluble fractions, these being further analyzed to establish th e distribution of molecular forms. All the tumors tested showed AChE a nd BuChE activities, the measured AChE/BuChE ratios being unrelated to the malignant grading. Hydrophilic and amphiphilic AChE and BuChE tet ramers, amphiphilic AChE dimers and monomers, and hydrophilic BuChE mo nomers were identified in all the tumors analyzed. The amphiphilic beh avior of the enzyme forms was assessed by sedimentation analysis and h ydrophobic chromatography on phenyl-Agarose. A small fraction of gliom a AChE monomers was released as, or transformed into, hydrophilic form s by incubation with phosphatidylinositol-specific phospholipase C (PI PLC). These data suggest that AChE monomers bearing distinct hydrophob ic domains coexist in human glioma.