Characterization of acetylcholinesterase activity from Drosophila melanogaster.
The acetylcholinesterase activity of the fruit fly, Drosophila melanogaster, was characterized biochemically. The activity is associated with a glycoprotein which is divided between a detergent-extractable membrane-bound fraction and a soluble fraction. The acetylcholinesterase activity is concentrated in the head of the insect. Through pharmacological methods, greater than 95% of the cholinesterase is judged to be true acetylcholinesterase, and not pseudocholinesterase. As expected for an acetylcholinesterase, the enzyme has a high affinity for acetylthiocholine and is inhibited by excess concentrations of acetylthiocholine. The soluble enzyme is found predominantly as a 7.8 S form; a smaller amount of an approximately 6 S form is also present, and a greater than or equal to 14 S form may exist. The detergent-solubilized acetylcholinesterase has a sedimentation coefficient of 7.5 S in the presence of detergent. The thermal inactivation rates for the soluble and the membrane bound enzymes are markedly different.
Melanson
S W
SW
Yun
C H
CH
Pezzementi
M L
ML
Pezzementi
L
L
D000110:Acetylcholinesterase / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D004331:Drosophila melanogaster / Q000201:enzymology*; D006023:Glycoproteins / Q000302:isolation & purification; D007700:Kinetics; D008970:Molecular Weight; D013379:Substrate Specificity; D014018:Tissue Distribution
D006023:Glycoproteins; D000110:Acetylcholinesterase