Cholinesterase (ChE)

Cholinesterase (ChE) is a family of enzymes present in the central nervous system, particularly in nervous tissue, muscle and red cells, which catalyze the hydrolysis of the neurotransmitter acetylcholine into choline and acetic acid, a reaction necessary to allow a cholinergic neuron to return to its resting state after activation. It is one of many important enzymes needed for the proper functioning of the nervous systems of humans.

There are two types: acetylcholinesterase (AChE, acetylcholine hydrolase) and butyrylcholinesterase (BChE, acylcholine acylhydrolase), also known as nonspecific cholinesterase or pseudocholinesterase. AChE is primarily found in the blood on red blood cell membranes, in neuromuscular junctions, and in neural synapses, while BChE is produced in the liver and found primarily in plasma. The difference between the two types of cholinesterase is their relative preferences for substrates: AChE hydrolyzes acetylcholine faster while BChE hydrolyzes butyrylcholine faster.