I.  Biological Significance

     Acetylcholinesterase (AChE) is a serine hydrolyze that hydrolyzes the ester bond of the neurotransmitter acetylcholine to choline and acetate(1).  As a result of this hydrolysis, the nerve impulses sent between neurons in the central and peripheral nervous systems are terminated(2).  The enzyme is bound to cellular membranes of excitable tissue(synaptic junction, endoplasmic reticulum, etc.) (3).  When an electrical impulse reaches the end of one cell, acetylcholine will be released to diffuse through the synaptic gap.  When it reaches its final site, the molecule connects with receptors to trigger a new impulse.  AChE is constantly collecting and hydrolyzing the acetylcholine so the cycle can start over.  Because of this and also how rapid the enzyme works, it is nicknamed "Nature's Vacuum".

     AChE is targeted by such things as nerve agents, insecticides and drugs for treating various neurological diseases.   Recently it has been the focus of drug developers who are searching for a way to handle Alzheimer's disease.