A new method to estimate the butyrylcholinesterase (BChE, EC 3.1.1.8) activity by using capillary electrophoresis (CE) coupled with electrochemiluminescence (ECL) is described. The liberated N,N-dimethylethanolamine (DMEA) that is produced by BChE catalyzed hydrolysis reaction of tetracine hydrochloride was used as ECL coreagent to enhance Ru(bpy)32+ ECL signals efficiently. The detection limit for DMEA was 1.98 × 10−8 M (S/N = 3), which is equal to 6.6 × 10−10 units of BChE used to catalyze substrate for 30 mins. The Michaelis constant Km (1.16 × 10−3 mol/L) and the maximum reaction velocity Vmax (2.71 × 10−7 mol/L/min) of BChE for tetracine hydrochloride are determined. Also, the reaction conditions including the concentration of metal ions, incubation temperature and pH were optimized. This method was successfully applied to detect BChE activity as a bio-marker in plasma and the results were in good agreement with that obtained by the clinical method.
Wang D, Li F, Su M, Sun H. Application of capillary electrophoresis coupling with electrochemiluminescence detection to estimate activity of butyrylcholinesterase. J App Pharm Sci, 2018; 8(04): 007-014.