Purification and Characterization of Cholinesterase from Duck Plasma

摘要

Cholinesterase from duck plasma was isolated and purified to electro-phoretic homogeneity by salting out, ion-exchange chromatography on DEAE-cellulose, and gel filtration on Sephadex G-200. The enzyme was purified 278.5-fold and 17.8 % activity was recovered. Studies on the properties of the Cholinesterase showed that the optimum temperature was 37 °C and the optimum pH was 7.5-8.0. The value of Km was 2.4 × 10~(-5) M and the enzyme was not inhibited by excess bcetylthiocholine iodide. The presence of Ca~(2+), Mg~(2+), and M~(n2+) increase the enzyme activity at a concentration of 5 mM. The study showed that this cholinesterase was a valuable alternative for detecting organophosphate and carbamate pesticides of vegetables and fruits.