مریم مهاجرانی

Acetylcholinesteras (AChE) function is to catalyze the hydrolysis of acetylcholine.Thus to maintain the homeostasis of this neurotransmitter is necessary in the central and peripheral nervous systems. Hence, AChE is important in both pharmacological and toxicological mechanisms. The present work was designated to purify and study the properties of acetylcholinesterase enzyme from fresh bovine brain. The enzyme was partially purified from bovine brain using homogenization, centrifugation, ammonium sulfate precipitation and dialysis at 4ºC. During purification steps, the enzyme activity was estimated according to Ellman method. The rate of production of thiocholine was measured by following the reaction of thiocholine with 5,5′-dithiobis-(2-nitrobenzoic acid), which produces a yellow colour because of formation of 5-thio-2-nitrobenzoic acid at 412 nm. The specific activity of the partially purified AChE was 2.43 IU/mg. The optimum pH and optimum temperature of the acetylcholinesterase were determined to be 7-8and 40 ºC respectively. Our results suggested that the bovine brain would be considered for study on enzymatic behavior of acetylcholinesterase.