Acetylcholinesterase and its association with lipid.

Human erythrocyte acetylcholinesterase preparations which vary in lipid content, from lipid-rich to lipid-poor, have been successfully prepared using deoxycholate. It was found that the lipid content of the enzyme decreased gradually as the deoxycholate concentration used in its preparation was increased. The binding of lipid to lipid-poor preparations of the enzyme has been investigated. It was found that the activity of such preparations was highly dependent on their phospholipid contents. Maximum specific activity was associated with a fixed phospholipid content. The lipid-poor enzyme was highly activated by addition of either endogenous(membrane) or exogenous lipid. Based on the data presented, it was concluded that acetylcholinesterase is a phospholipoprotein, and its activity is highly dependent on its phospholipid component.