Acetylcholinesterases from Musca domestica and Drosophila melanogaster brain are linked to membranes by a glycophospholipid anchor sensitive to an endogenous phospholipase.
The sensitivity of acetylcholinesterases (AChEs) from Musca domestica and from Drosophila melanogaster to the phosphatidylinositol-specific phospholipase C from Bacillus cereus and to the glycosylphosphatidylinositol-specific phospholipase C from Trypanosoma brucei was investigated. B. cereus phospholipase C solubilizes membrane-bound AChE, and both phospholipases convert amphiphilic AChEs into hydrophilic forms of the enzyme. The lipases uncover an immunological determinant that is found on other glycosylphosphatidylinositol-anchored membrane proteins after the same treatment. This immunological determinant is also present on the native hydrophilic form of AChE. The polypeptide bearing the active site of the membrane-bound enzyme migrates faster during sodium dodecyl sulfate-polyacrylamide gel electrophoresis than the same polypeptide from the soluble enzyme. We conclude that AChE from insect brain is attached to membranes via a glycophospholipid anchor. This anchor is covalently linked to the polypeptide bearing the active esterase site of the enzyme and can be cleaved by an endogenous lipase.
Fournier
D
D
INRA, Centre de Recherche d'Antibes, France.
Bergé
J B
JB
Cardoso de Almeida
M L
ML
Bordier
C
C
D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D001409:Bacillus cereus / Q000201:enzymology; D001921:Brain / Q000201:enzymology; D002462:Cell Membrane / Q000201:enzymology; D004331:Drosophila melanogaster / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D054800:Glycosylphosphatidylinositol Diacylglycerol-Lyase; D006793:Houseflies / Q000201:enzymology*; D007118:Immunoassay; D007700:Kinetics; D046911:Macromolecular Substances; D008563:Membrane Lipids / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D010716:Phosphatidylinositols / Q000378:metabolism*; D054801:Phosphoinositide Phospholipase C; D010740:Phospholipases / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D012995:Solubility; D014346:Trypanosoma brucei brucei / Q000201:enzymology; D010738:Type C Phospholipases
D046911:Macromolecular Substances; D008563:Membrane Lipids; D008565:Membrane Proteins; D010716:Phosphatidylinositols; D010740:Phospholipases; D000110:Acetylcholinesterase; D010727:Phosphoric Diester Hydrolases; D010738:Type C Phospholipases; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D054800:Glycosylphosphatidylinositol Diacylglycerol-Lyase