Abstract: The distribution in body and subcellular distributions and purification of cetylcholinesterase (AChE) in insecticide-resistant population of Chilo suppressalis were investigated. AChE was purified from the larvae of the same population by gel filtration and 2 species of affinity chromatography on 3-carboxyphenyl ethyldimethyl ammonium (CEA) and procainamide. The results showed that specific activity of AChE in adults was higher than that in larvae. AChE in larvae was distributed mostly in the head and the thorax; while in adults, AChE activity in thorax was lower than those in the head and the abdomen significantly. The major portion of the total AChE was member-bound (86%) and associated primarily with microsome (46%). Affinity chromatography on CEA was optimum for purification of AChE among 3 species purified methods. The extent of purification reached about 536.05-folds with recoveries of 30.46%.

Key words: Chilo suppressalis, acetylcholinesterase, affinity chromatography, distribution, purification