The kinetic inhibition of acetylcholinesterase from human herytrocyte by tacrine and some tacrine derivatives

The kinetics of the reaction catalyzed by human erythrocyte Acetylcholinesterase (AChE) is studied in the presence of its inhibitor Tacrine (1,2,3,4-tetrahydro-9-acridinamine), and of two newly synthesized compounds, 6-metoxy-Tacrine and N-eptyl-Tacrine. The proposed kinetic model describes the rate of the enzymatic reaction in terms of competitive and uncompetitive mixed inhibition of the three different inhibitors. The kinetic parameters describing the rate of the reaction are obtained. The competitive and uncompetitive inhibition constants of the different inhibitors are reported and the mixed competitive-uncompetitive inhibition is discussed. (C) 1999 Academic Press.