Abstract: An affinity chromatography column was prepared by cross-linking of 3-carboxyphenyl ethyldimethyl ammonium (CEA) as a ligand with CNBr-Sepharose-4B and used for an investigation into the optimization of elution conditions for affinity chromatography of acetylcholinesterase (AChE) from the gut of sea cucumber (Stichopus japonica). The appropriate balance system was PBS (0.05 mol/L, pH 7.4) containing 0.3 mol/L NaCl, and the appropriate elution system was PBS (0.05 mol/L, pH 7.4) containing 0.2 mol/L tetraethyl ammonium iodide. Under these conditions, AChE was well adsorbed and separated. Three active bands were separated in the native-PAGE pattern of Preliminarily purified AChE, AChE in the gut of sea cucumber may have different forms and display polymorphism.

Key words: sea cucumber, acetylcholinesterase, affinity chromatography, elution conditions