Expression of recombinant human acetylcholinesterase and its application in screening its inhibitors

This study is designed to obtain recombinant human acetylcholinesterase (rhAChE) and apply it in screening acetylcholinesterase inhibitors. The rhAChE was overexpressed in HEK293 cells transfected by plasmid of pCMV-AChE with the cationic liposome and rhAChE was found to be secreted into cell culture medium. AChE activity was assayed according to modified Ellman method to obtain kinetic parameters. IC₅₀ values for donepezil compounds of rhAChE were calculated to determine their activities of inhibition. The results showed that K_m value was 151.9 祄ol·L^-1, donepezil inhibited rhAChE in a mixed competitive-non-competitive way (K_i = 16.03 nmol·L^-1, K_i' = 18.36 nmol·L^-1) and that most new compounds tested exhibited high activities of inhibition on rhAChE. The study suggests that rhAChE is available to be applied in screening AChE inhibitors in vitro.