Extraction of liver acetylcholinesterase in Oreochromis aurea by aqueous two-phase system

Acetylcholinesterase (AChE, EC3.1.1.7) plays an important role in environmental insecticide detection. Extraction of liverAcetylcholinesterase(AChE) in Oreochromis aurea by aqueous two-phase system (ATPS) was studied. The effects of K2HPO4 concentration,polyethylene glycol 1000 (PEG1000) concentration, pH value and NaCl concentration on the extraction of liver AChE were investigated.Orthogonal experiment was used to optimize the extraction of AChE. The results showed that K2HPO4 concentration, PEG1000 concentration and pH value had important effects on partitioning of AChE. Optimum separation of AChE was obtained with a maximumpartition coefficient 5.65 and recovery 72% under the extraction conditions of 15.0% K2HPO4, 22.0% PEG1000 and pH 7.0 at room temperature. Scaled-up experiments indicated this system was stable in separation of AChE.