Abstract:

Acetylcholinesterase (AChE) was purified from porcine brain by consecutive steps including centrifugation,ammonium sulfate fractionation, DEAE-Sepharose chromatography and Superdex-200 gel filtration chromatography. Thepurified AChE exhibited a specific activity of 2.05 U/mg, with 26.97-fold purification and an activity yield of 11.95%. Therelative molecular weight of AChE was 257.30 kD, and the subunit molecular weight was 66.94 kD. The optimal pH andtemperature for the enzyme were 7.4 and 37 ℃, respectively. The enzyme was stable below 40 ℃ and in the pH range of6.0–8.0. At an optimal substrate concentration of 4.0 mmol/L, the apparent Km was 0.94 mmol/L. The activity of AChE wasinhibited by Ba2+ or Zn2+ , but enhanced by Mg2+.

Key words: acetylcholinesterase, porcine brain, isolation and purification, characterization