Identification of covalently bound inositol in the hydrophobic membrane-anchoring domain of Torpedo acetylcholinesterase.
The hydrophobic, membrane-bound form of Torpedo acetylcholinesterase is specifically solubilized by a phosphatidylinositol-specific phospholipase C, suggesting that acetylcholinesterase is bound to the membrane via a direct and specific interaction with phosphatidylinositol (Futerman et al., Biochem. J. (1985) 226, 369-377). Here we demonstrate the presence of covalently bound inositol in the membrane-anchoring domain of purified Torpedo acetylcholinesterase. Upon removal of this domain, levels of inositol are reduced to only 15-20% of those found in the intact enzyme. The results presented strongly support our suggestion that phosphatidylinositol is indeed involved in anchoring acetylcholinesterase to the plasma membrane.
D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D004557:Electric Organ / Q000201:enzymology; D008401:Gas Chromatography-Mass Spectrometry; D007294:Inositol / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism; D012995:Solubility; D014101:Torpedo; D010738:Type C Phospholipases / Q000378:metabolism
D010716:Phosphatidylinositols; D007294:Inositol; D000110:Acetylcholinesterase; D010738:Type C Phospholipases