Acetylcholinesterase (Electric eel)

Acetylcholinesterase (Electric eel) (AChE) is a cholinergic enzyme primarily found at neuromuscular junctions and cholinergic synapses. The main function of acetylcholinesterase (Electric eel) is to catalyze the decomposition or hydrolysis of acetylcholine and other acetylcholine esters into acetic acid and choline, thereby terminating signal transmission between neurons and synapses, preventing the diffusion and activation of acetylcholine (ACh) nearby receptors, and is utilized in biochemical research^[1].

Under conditions of 37℃, 0.1 mol/L pH=8.0 phosphate buffer, the enzyme activity of acetylcholinesterase is measured by the amount of enzyme required to decompose 1 μmol of acetylthiocholine iodide (ATCI) per minute, defined as one unit of acetylcholinesterase activity.

Under certain conditions, organophosphates and carbamates inhibit the normal function of cholinesterase. The degree of inhibition is directly proportional to the concentration of pesticides. Normally, the enzyme catalyzes the hydrolysis of the neurotransmitter metabolite (acetylcholine), which reacts with a color developer to produce a yellow substance. The absorbance changes over time are measured using a spectrophotometer, and the inhibition rate is calculated. The presence of organophosphates and carbamates in the product can be determined by the inhibition rate.

References:

[1]. Israel Silman, et al. Acetylcholinesterase: how is structure related to function? Chem Biol Interact. 2008 Sep 25;175(1-3):3-10.

乙酰胆碱酯酶（电鳗鱼）（AChE）是一种胆碱能酶，主要存在于神经肌肉接头和胆碱能型化学突触中。乙酰胆碱酯酶（电鳗鱼）主要作用是催化乙酰胆碱和其他胆碱酯酶分解或水解成乙酸和胆碱，终止神经元传递和突触之间的信号传递，防止乙酰胆碱（Ach）扩散和激活附近的受体，用于生物化学研究^[1]。

在37℃，0.1mol/L pH=8.0磷酸缓冲液条件下，每分钟分解1umol碘化硫代乙酰胆碱（ATCI）的酶量为一个乙酰胆碱酯酶活力单位。

在一定条件下有机磷和氨基甲酸酯类对胆碱酶正常功能有抑制作用，其抑制率与农药浓度成正比关系，正常情况下，酶催化神经传导代谢产物（乙酰胆碱）水解，其水解产物与显色剂反应，产生黄色物质，用分光光度计测定吸光度随时间的变化值，计算出抑制率。通过抑制率可测出产品中是否含有有机磷和氨基甲酸酯类农药的存在。