Purification and characterization of acetylcholinesterase,a kind of pesticide target

Acetylcholinesterase(AChE) of Bombyx mori Linaeus,separated from the crude extract,was purified to electrophoretic homogeneity by Sephadex G-25 chromatography,DEAE-Sepharose Fast Flow ion-exchange chromatography and Sephacryl S-200 gel filtration,respectively.The Molecular weight of the purified enzyme was 77.8 kDa,measured by SDS-PAGE.The optimum temperature of the AChE was 37 ℃,above which the enzyme would be unstable.It exhibited optimum activity at pH 7.5.The Michaelis constant for acetylthiocholine iodide was 0.392 mmol/L.The optimum concentration of substrate was 1.6 mmol/L,and the enzyme could be inhibitied by high level of acetylthiocholine iodide.