An electrochemical platform for acetylcholinesterase activity assay and inhibitors screening based on Michael addition reaction between thiocholine and catechol-terminated SAMs

• Published in: Analyst (London) 2011-12, Vol.136 (23), p.584-59
• Main Authors: Tian, Yuan, Ye, Siqiu, Shi, Xinhao, Jing, Li, Liang, Cong, Xian, Yuezhong
• Format: Article
• Language: English
• Subjects: Acetylcholinesterase - metabolism; Acetylthiocholine - metabolism; Analytical chemistry; Assaying; Biosensing Techniques; Carbofuran - pharmacology; Catechols - chemistry; Chemistry; Cholinesterase Inhibitors - analysis; Cholinesterase Inhibitors - chemistry; Cholinesterase Inhibitors - pharmacology; Corrosion inhibitors; Cysteine - chemistry; Cysteine - metabolism; Electrical measurements; Electrochemical methods; Electrochemical Techniques - methods; Electrodes; Exact sciences and technology; Glutathione - chemistry; Glutathione - metabolism; Gold; Inhibition; Methyl Parathion - pharmacology; Michael reaction; Platforms; Screening; Tacrine - pharmacology; Thiocholine - chemistry
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/c1an15601b

An electrochemical platform for acetylcholinesterase (AChE) activity assay and its inhibitors screening is developed based on the Michael addition reaction of thiocholine, the hydrolysis product of acetylthiocholine (AsCh) in the presence of AChE, with the electrogenerated o -quinone of catechol-terminated SAMs on a gold electrode. For understanding and confirming the mechanism of the reaction, the electrochemical behaviors of Michael addition reaction of two model compounds, cysteine (CYS) and glutathione (GSH), towards the catechol-terminated SAMs have been studied. The enzyme kinetics and the inhibition effects of three types of AChE inhibitors, which are tacrine, carbofuran and parathion-methyl, have been investigated using an amperometric method. Among these three inhibitors, tacrine exhibits the strongest inhibiting effect, which is reinforced by the resulting data of kinetic studies on each inhibitor's influence upon the enzyme activity. A simple and versatile electrochemical platform for acetylcholinesterase (AChE) activity assay and its inhibitors screening is developed based on the Michael addition reaction of thiocholine with the electrogenerated o -quinone of catechol-terminated SAMs on a gold electrode.